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  • Coleoptera  (58)
  • photosynthesis  (52)
  • Springer  (110)
  • American Meteorological Society
  • Periodicals Archive Online (PAO)
  • 1995-1999
  • 1990-1994  (110)
  • 1935-1939
  • 1994  (110)
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  • Springer  (110)
  • American Meteorological Society
  • Periodicals Archive Online (PAO)
  • Wiley-Blackwell  (2)
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  • 1995-1999
  • 1990-1994  (110)
  • 1935-1939
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  • 1
    Electronic Resource
    Electronic Resource
    Abiotic mortality factors of the coffee berry borer (Hypothenemus hampei) (1994)
    Springer
    Entomologia experimentalis et applicata 71 (1994), S. 201-209 
    Details
    ISSN: 1570-7458
    Keywords: Hypothenemus hampei ; coffee berry borer ; abiotic mortality ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Mortality of the coffee berry borer was studied under controlled laboratory conditions in Tapachula, Mexico. For adult female borers subjected to a range of relative humidities (RH) without food at 25°C, the longest mean survival time (20 days) was obtained at 93.5% RH. Adult borer survival was also studied at a range of temperatures for a fixed relative humidity (93.5% RH); at 20°C mean survival time was 28 days. Fecundity and mortality of borer stages in berries was studied for a range of humidities at 25°C. Maximum fecundity was obtained at 90 and 93.5% RH. Immature stages were ejected from the berry at 84% RH and above, which is interpreted as a form of brood hygiene.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02426404
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  • 2
    Electronic Resource
    Electronic Resource
    Behavioral responses of Colorado potato beetle larvae to combinations of temperature and insolation, under field conditions (1994)
    Springer
    Entomologia experimentalis et applicata 72 (1994), S. 255-263 
    Details
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; behavior ; thermal biology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In short-term field trials at combinations of ambient temperature (°C) and insolation (W·m−2), larval Colorado potato beetles (Leptinotarsa decemlineata [Say] [Coleoptera: Chrysomelidae]) were observed after their release on the adaxial surface of leaflets on potato plants (Solanum tuberosum L. Solanaceae). The larvae either began feeding or moved under the leaflet; mean interval from release to expression of these behaviors (2.9±0.05 min [n =358]) was independent of air temperature and insolation. Proportion of larvae moving under the leaflet increased logistically with both air temperature and insolation. A 1 W·m−2 change in insolation (P) evoked the same effect on this proportion as a 0.0838 °C change in air temperature (T a ), so the two quantities were combined as T*=T a +P·0.0838 °C/(W·m−2), which has units of °C. The proportion of larvae moving under the leaflet increased logistically with T*. In 1-day field trials we monitored air temperature, insolation and proportion of larvae under the leaflet, and compared the latter to predictions from the logistic regression derived from the short-term trials. Consistently more larvae occurred under leaflets than predicted from the logistic regression; this bias diminished as T* increased until at T*≥40 °C, observed and predicted proportions were equal. This pattern of deviation from the predictions of the logistic regression is consistent with a thermoregulatory strategy in which larvae move away from hostile conditions, rather than seek optimal conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02383813
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  • 3
    Electronic Resource
    Electronic Resource
    Examination of anAspergillus flavus resistant inbred of maize for crossresistance to sap beetle vectors (1994)
    Springer
    Entomologia experimentalis et applicata 71 (1994), S. 177-180 
    Details
    ISSN: 1570-7458
    Keywords: aflatoxin ; Carophilus ; Zea mays ; corn ; plant resistance ; Coleoptera ; Nitidulidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382385
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  • 4
    Electronic Resource
    Electronic Resource
    Glandular trichomes ofSolanum berthaultii alter host preference of the Colorado potato Beetle,Leptinotarsa decemlineata (1994)
    Springer
    Entomologia experimentalis et applicata 70 (1994), S. 217-225 
    Details
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; plant resistance ; glandular trichomes ; host preference ; behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Choice and no-choice studies were conducted to determine how the glandular trichomes of the wild potato,Solanum berthaultii Hawkes, affect host preference of the Colorado potato beetle,Leptinotarsa decemlineata (Say). Given a feeding choice betweenS. tuberosum andS. berthaultii, larvae and adults preferred the foliage ofS. tuberosum, but adults were more discriminating. When foliage ofS. berthaultii was appressed toS. tuberosum leaflets, fewer adults fed on the appressed leaflets. When given a choice between ‘trichome-intact’ and ‘trichome-removed’S. berthaultii foliage, adults preferred to feed on the latter. The preference for ‘trichome-removed’ foliage and the percent of adults initiating feeding, increased with the degree of trichome removal. These studies provide evidence that the resistance ofS. berthaultii is associated with feeding deterrents localized in the glandular trichomes, thatS. berthaultii possesses more than one mechanism of resistance to the Colorado potato beetle, and that the expression of resistance is dependent on the developmental stage of the insect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02380555
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  • 5
    Electronic Resource
    Electronic Resource
    The role of symbiotes in flight activity ofSitophilus weevils (1994)
    Springer
    Entomologia experimentalis et applicata 70 (1994), S. 201-208 
    Details
    ISSN: 1570-7458
    Keywords: Sitophilus oryzae ; S. zeamais ; Coleoptera ; Curculionidae ; flight activity ; symbiosis ; vitamin ; amino acid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Résumé Les performances de vol de nombreuses souches deSitophilus oryzae L. etS. zeamais Mots. (Coleoptera, Curculionidae) ont été comparées sur blé. Il s’avère que les mâles sont plus actifs que les femelles et queS. zeamais possède une meilleure aptitude au vol queS. oryzae. De plus, dans les deux espèces élevées sur blé, seuls les charançons normalement symbiotiques sont capables de voler, tandis que les aposymbiotiques ont perdu ce pouvoir. En complémentant la nourriture avec des vitamines (acide pantothénique et riboflavine) et certains acides aminés (phénylalanine et proline), cette activité a pu être restaurée en partie. L’influence de la symbiose sur l’aptitude au vol du charançon du genreSitophilus est commentée en fonction du métabolisme énergétique (coenzymes, proline) et du rôle joué par la symbiose dans ce comportement qui permet d’augmenter la dissémination de l’espèce.
    Notes: Abstract The flight activity (take-off) of various strains ofSitophilus oryzae L. andS. zeamais Mots. (Coleoptera, Curculionidae) have been compared on wheat. It was shown that males are more active than females and thatS. zeamais, is more active thanS. oryzae. Furthermore, in the two species, when reared on wheat kernels, only symbiotic weevils were able to fly, while aposymbiotic insects did not. By supplementation of the diet with vitamins (pantothenic acid, riboflavin) and amino acids (phenylalanine and proline), this activity could be restored in part. The influence of symbiosis on the flight ability ofSitophilus weevil is discussed in relation to the energy metabolism (coenzymes, proline), the role played by symbiosis in this behaviour and its possible effect on the dissemination of the species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02380553
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  • 6
    Electronic Resource
    Electronic Resource
    Disrupting spring colonization of Colorado potato beetle to nonrotated potato fields (1994)
    Springer
    Entomologia experimentalis et applicata 73 (1994), S. 39-50 
    Details
    ISSN: 1570-7458
    Keywords: Leptinotarsa decemlineata ; Coleoptera ; Chrysomelidae ; distribution ; overwintering ; diapause ; cultural control ; trap cropping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Overwintering Colorado potato beetles (Leptinotarsa decemlineata (Say)) were concentrated primarily within woody borders, and mortality was lower in borders than in potato fields. After overwintering, only 15–44% of live beetles were in the potato fields. In experiments with small plots, colonization of fields from woody borders was reduced ∼60% by a trap crop, either treated with adulticide or with beetles collected daily. Such trap crops, or simply pitfall traps to prevent colonization from woody borders, could significantly reduce early-season adult numbers and subsequent larval populations. However, success is dependent on the local densities of overwintered beetles, and the prevalence of arrestment behavior in the case of trap crops.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02382512
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  • 7
    Electronic Resource
    Electronic Resource
    Selection response of the Colorado potato beetle for adaptation to the resistant potato,Solanum berthaultii (1994)
    Springer
    Entomologia experimentalis et applicata 73 (1994), S. 101-109 
    Details
    ISSN: 1570-7458
    Keywords: Coleoptera ; Chrysomelidae ; Leptinotarsa decemlineata ; Colorado potato beetle ; Solanaceae ; Solanum berthaultii ; potato ; plant resistance ; selection ; adaptation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Thirty cohorts of the Colorado potato beetle (CPB) were reared for ten consecutive generations on the cultivated potato,Solanum tuberosum, and on two accessions (PI 473331 and PI 473334) of the resistant wild species,S. berthaultii. At each generation, selection was imposed for increased survival, decreased development time, and for increased fecundity. Although several parameters responded to selection, net replacement rate (R0) onS. berthaultii was consistently less than 1/3 that on cultivated potato. At the tenth generation, eachS. tuberosum strain female replaced herself with 110 daughters, whereas females from strains reared on PI 473334 and PI 473331 produced an average of 30 and 7 daughters, respectively. Slopes of the R0 regression lines for populations reared onS. tuberosum andS. berthaultii did not differ from zero, indicating no significant response to selection. Our findings suggest that populations of the Colorado potato beetle may have genetic variability in some performance traits for adaptation toS. berthaultii, but that adaptation is unlikely to occur as rapidly as previously reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02383415
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  • 8
    Electronic Resource
    Electronic Resource
    Flash behavior of femalePhoturis versicolor fireflies (Coleoptera: Lampyridae) in simulated courtship and predatory dialogues (1994)
    Springer
    Journal of insect behavior 7 (1994), S. 843-858 
    Details
    ISSN: 1572-8889
    Keywords: firefly ; entrainment ; insect communication ; Coleoptera ; aggressive mimicry ; bioluminescence ; Lampyridae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract FemalePhoturis versicolor fireflies attempt to capture males by responding to heterospecific flash patterns. A mating-dependent switch occurs which affects response timing and frequency of female flashes. We examined the switch using females of known age, mating status, and flash experience to assess how accurate mimicry is, what factors influence it, and what mechanism produces it. Presentations of simulated male flash patterns before and after mating revealed elements of an entrainment mechanism controlling female responsiveness. Unmated females preferentially answered conspecific patterns with variable latencies, averaging 1 s. Mating induced changes in both response frequency and response latency: Females answered heterospecific patterns more frequently, and latencies elicited by conspecific patterns shifted away from the unmated range. Heterogeneity in mean and variance of response latency among individuals indicates that females do not share a discrete reply to a given pattern. Little correspondence exists between latencies of sympatric species andP. versicolor females, suggesting that the flash response mechanism produces entriainment to any rhythmic pattern, not a one-to-one matching between prey and predator latencies. Different selective scenarios underlie strict mimicry versus entrainment mimicry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01997130
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  • 9
    Electronic Resource
    Electronic Resource
    Effect of nickel on certain physiological and biochemical behaviors of an acid tolerantChlorella vulgaris (1994)
    Springer
    BioMetals 7 (1994), S. 193-200 
    Details
    ISSN: 1572-8773
    Keywords: Chorella vulgaris ; acid tolerance ; ATPase ; nickel toxicity ; nutrient uptake ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This study concerns the inhibitory effects of acid pH and nickel on growth, nutrient (NO3 - and NH4 +) uptake, carbon fixation, O2 evolution, electron transport chain and enzyme (nitrate reductase and ATPase) activities of acid tolerant and wild-type strains of Chlorella vulgaris. Though a general reduction in all these variables was noticed with decreasing pH, the tolerant strain was found to be metabolically more active than the wild-type. A reduced cation (NH4 +, Na+, K+ and Ca2+) uptake, coupled with a facilitated influx of anions (NH4 +, PO4 3- and HCO3 -), suggested the development of a positive membrane potential in acid tolerant Chlorella. Nevertheless, a tremendous increase in ATPase activity at decreasing pH revealed the involvement of superactive ATPase in exporting H+ ions and keeping the internal pH neutral. A difference in Na+ and K+ efflux of the two strains at decreasing pH suggests there is a difference in membrane permeability. The low toxicity of Ni in the acid tolerant strain may be due to the low Ni uptake brought about by a change in membrane potential as well as in permeability. Hence, the development of superactive ATPase and a change in both membrane potential and permeability not only offers protection against acidity, but also co-tolerance to metals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00140491
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  • 10
    Electronic Resource
    Electronic Resource
    Comparison of the insecticidal effects of water extracted and intact aromatic plants onAcanthoscelides obtectus, a bruchid beetle pest of kidney beans (1994)
    Springer
    Chemoecology 5-6 (1994), S. 1-5 
    Details
    ISSN: 1423-0445
    Keywords: adult mortality ; oviposition inhibition ; larval mortality ; aromatic hydrodistillated and non hydrodistillated plants ; Coleoptera ; Bruchidae ; Acanthoscelides obtectus ; Lamiaceae ; Origanum ; Thymus ; Satureia ; Rosmarinus ; Mentha ; Myrtaceae ; Eucalyptus ; Lauraceae ; Laurus ; Poaceae ; Cymbopogon
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01259966
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  • 11
    Electronic Resource
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    Ladybird defence alkaloids: Structural, chemotaxonomic and biosynthetic aspects (Col.: Coccinellidae) (1994)
    Springer
    Chemoecology 5-6 (1994), S. 173-183 
    Details
    ISSN: 1423-0445
    Keywords: chemical defence ; sequestration ; reflex bleeding ; alkaloids ; chemotaxonomy ; biosynthesis ; repellency ; toxicity ; Coleoptera ; Coccinellidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The defensive mechanisms which protect ladybird beetles (Coccinellidae) against predators are reviewed. Besides behavioural mechanisms, such as thanatosis and reflex bleeding, chemical defence mechanisms are playing a prevalent role. Indeed, ladybirds are protected not only by their smell, but also by repulsive alkaloids, most of which are considered to be of autogenous origin. In a few cases, dietarily-acquired substances are also involved. Particular emphasis is laid on the repellent alkaloids which are contained in the haemolymph of many species. The structures of 34 nitrogen-containing compounds isolated so far are presented, and their distribution within the family is discussed in the light of the most widely accepted classification of these beetles. To conclude, the mode of release of the alkaloids, their variation through the life cycle and their repellent and toxic properties are discussed, as well as the few biosynthetic data yet available.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01240602
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  • 12
    Electronic Resource
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    Chemoecological studies of the exocrine glandular larval secretions of two chrysomelid species (Coleoptera):Phaedon cochleariae andChrysomela lapponica (1994)
    Springer
    Chemoecology 5-6 (1994), S. 185-189 
    Details
    ISSN: 1423-0445
    Keywords: oviposition ; repellents ; larval secretion ; Coleoptera ; Chrysomelidae ; Phaedon cochleariae ; Chrysomela lapponica
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The exocrine glandular secretions of larvae of the subfamily Chrysomelinae are known to repel conspecific adults, other competitive phytophagous insects and natural enemies. InPhaedon cochleariae, the intraspecific activity of tlc fractions of the larval secretion was tested in order to examine the ecological significance of two fractions containing minor components and a fraction containing the major compound, the cyclopentanoid monoterpene (epi)chrysomelidial. InChrysomela lapponica, the defensive activity of the larval secretion against ants is known from specimens feeding upon willow or birch. The feeding preferences of larvae and adults ofC. lapponica from a Finnish and a Czech population were tested. The Finnish individuals significantly preferred feeding uponSalix borealis, whereas they hardly fed upon birch. The Czech specimens clearly preferred birch (Betula pubescens) to willow species. Application of salicin onto leaves of a willow species free of this phenolglycoside revealed that the Finnish individuals preferred feeding upon leaves with salicin. On the other hand, the Czech individuals avoided feeding upon leaves ofB. pubescens treated with salicin. The chemical composition of the glandular secretion of the Finnish larvae differed from the one of the Czech larvae. GC-MS-analyses of the secretions revealed that salicylaldehyde was the only major component of the secretion of Finnish larvae feeding upon the salicin-containing willowS. borealis. The glandular secretion of the Czech larvae feeding upon birch contained numerous esters of isobutyric acid and 2-methylbutyric acid. When Czech larvae had fed upon a salicin-containing willow (S. fragilis), the major compounds of their secretion were benzoic acid, salicylalcohol and benzoic acid esters; salicylaldehyde was only detected in traces. Thus,C. lapponica individuals from the Finland population adapted so closely to a salicincontaining willow that they clearly prefer this plant for food and that they obviously derive their main larval defensive compound (salicylaldehyde) from their host-plant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01240603
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  • 13
    Electronic Resource
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    Sexual dimorphism in the lipid fraction of the defensive secretion ofGastrophysa viridula (Coleoptera: Chrysomelidae) (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 766-770 
    Details
    ISSN: 1420-9071
    Keywords: Gastrophysa viridula ; Chrysomelidae ; Coleoptera ; chemical defence ; acetates ; hydrocarbons ; gas-liquid chromatography ; gas chromatography-mass spectrometry ; sexual dimorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The lipid fraction of the defensive secretion of adultGastrophysa viridula was analyzed by gas-liquid chromatography and gas chromatography-mass spectrometry. Three long chain acetates and two methyl-branched hydrocarbons were identified and their amounts in the secretion of single field-collected and laboratory-reared beetles determined. The composition of the secretion was affected by the sex, reproductive status, and age of the beetle. The ratio of (Z)-11-eicosenyl acetate to (Z)-13-docosenyl acetate ranged from 0.30 to 0.78 in male beetles and from 1.05 to 2.06 in female beetles. The biological significance of this sexual dimorphism is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01919379
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  • 14
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    Female sex pheromone of the longhorn beetleMigdolus fryanus Westwood: N-(2′S)-methylbutanoyl 2-methylbutylamine (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 853-856 
    Details
    ISSN: 1420-9071
    Keywords: Migdolus fryanus ; Coleoptera ; Cerambycidae ; N-2′-methylbutanoyl 2-methylbutylamine ; N-formyll-isoleucine methyl ester ; sex pheromone ; chiral resolution ; dose-response
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The first known long-range female-released sex pheromone for the family Cerambycidae is reported fromMigdolus fryanus, a sugarcane pest in South America. Although two female-specific compounds, namely, N-(2′S)-methylbutanoyl 2-methylbutylamine and N-formyll-isoleucine methyl esters were identified, field tests with synthetic chemicals revealed that only the amide was active and that the amino acid derivative neither increased or decreased trap catches by the amide. This is the first identification of amide as a sex pheromone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01956471
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  • 15
    Electronic Resource
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    Field tests of a balloon-suspended trap system for studying insects in the canopy of tropical rainforests (1994)
    Springer
    Ecological research 9 (1994), S. 357-360 
    Details
    ISSN: 1440-1703
    Keywords: balloon system ; Coleoptera ; pollinators ; tree canopy ; wood borers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A system of suspending traps from a movable balloon was developed and tested on pollinating and wood boring Coleoptera in a tropical rainforest canopy in Pasoh Forest Reserve, Peninsular Malaysia. The balloons, 2.5 m in diameter, were filled with helium gas for levitation and moored in different directions by three pieces of thin rope. Traps in which benzyl acetate and ethanol were used as attractants for the pollinators and wood borers, respectively, were suspended from the balloon at different heights. The trapping results show that the balloon system can be used for studying canopy insects and their vertical distribution on a spatial and temporal scale.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02348423
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  • 16
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    Evidence for volatile chemical attractants in the beetleMaladera matrida argaman (Coleoptera: Scarabaeidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2673-2685 
    Details
    ISSN: 1573-1561
    Keywords: Maladera matrida ; Coleoptera ; Scarabaeidae ; collection of volatiles ; field trapping ; olfactometer ; attractants ; host plant volatiles ; synergism ; aggregation ; sex pheromone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract TheMaladera matrida beetle (Coleoptera, Scarabaeidae, Melolonthinae), a relatively new species to science, was first identified in Israel in 1983. In the course of field observations it was found that adultM. matrida beetles emerged from the soil at sunset to feed and mate. During the first 20 min of flight, most of the beetles were males. The females emerged shortly afterwards, and aggregations numbering 20–30 individuals with equal proportions of males and females were eventually formed on peanut plants. Laboratory olfactometer bioassays showed that peanut leaves (food) attracted both males and females. Field-trapping experiments and olfactometer studies showed thatM. matrida beetles were highly attracted by live virgin females in the presence of food (cut-up peanut leaves). Another set of field trapping experiments indicated that airborne volatiles produced by live virgin females plus food had the same attracting ability as live virgin females plus food. The attraction exerted by the combination of live virgin females and peanut leave volatiles suggests a synergism effect. Accordingly, we propose a two-stage mechanism of chemical communication in theM. matrida beetles: first, the males cause mechanical damage to the host plant to attract both sexes; later, the females emit attractants (sex pheromone) while eating or shortly thereafter.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02036200
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  • 17
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    Mechanism of aggregation behavior inMaladera matrida Argaman (Coleoptera: Scarabaeidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 361-371 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Scarabaeidae ; Maladera matrida ; aggregation ; plant volatiles ; olfactometer ; attractant ; behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract AdultMaladera matrida Argaman (Coleoptera: Scarabaeidae: Melolonthinae) males emerge from soil for an active period at dusk, a few minutes before the females. Adults are found during most of the active hours on the foliage in aggregations composed of an equal sex ratio. The mechanism of aggregation behavior ofM. matrida beetles was studied in a Y-shaped olfactometer. No evidence was found for the existence of an aggregation pheromone released either by males or by females, but behavior tests indicate that adultM. matrida beetles, males as well as females, are attracted to volatiles of an injured host plant. The following scenario is suggested: Males emerge daily from soil at dusk, a few minutes before the females, and immediately start feeding. Additional males are attracted to the injured host's volatiles and form aggregations. When females emerge from soil, the attractant volatiles are concentrated in spots, and the females join the aggregations, forming an equal sex ratio.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02064443
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  • 18
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    Tasting green leaf volatiles by larvae and adults of Colorado potato beetle,Leptinotarsa decemlineata (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 753-769 
    Details
    ISSN: 1573-1561
    Keywords: Contact chemoreception ; electrophysiology ; taste ; leaf alcohols ; galeal sensilla ; feeding behavior ; host selection ; gustatory coding ; Colorado potato beetle ; Leptinotarsa decemlineata ; Coleoptera ; Chrysomelidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Larvae and adults of the Colorado potato beetle,Leptinotarsa decemlineata (Say), are shown to have galeal gustatory cells that are highly sensitive to distillate of potato leaf extracts, (E)-2-hexen-1-ol, (E)-2-hexenal, and other saturated and unsaturated six-carbon alcohols. In larvae and adults, the sensory response patterns elicited by leaf homogenate, leaf distillate and a mixture of these two extracts differ in subtle ways. Beetle larvae feed most readily on Millipore disks treated with leaf homogenate and the mixture, but they did not feed on disks treated with leaf distillate. The differences in behavioral response and sensory input are used to derive a potential gustatory code that may stimulate different levels of feeding. This code may be disrupted by compounds present in nonhost leaves, thus leading to reduced feeding. Possible interactions of sapid leaf volatiles, amino acids, sugars, and potentially deterrent plant compounds are discussed.
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    URL: http://dx.doi.org/10.1007/BF02059611
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    Reduced offspring production in bark beetleTomicus piniperda in pine bolts baited with ethanol and α-pinene, which attract antagonistic insects (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1429-1444 
    Details
    ISSN: 1573-1561
    Keywords: Tomicus piniperda ; Thanasimus formicarius ; Rhizophagus depressus ; Rhizophagus ferrugineus ; Epuraea spp. ; Acanthocinus aedilis ; predators ; competitors ; attractants ; α-pinene ; ethanol ; Scolytidae ; Cleridae ; Rhizophagidae ; Cerambycidae ; Coleoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Bolts of Scots pine,Pinus sylvestris L., attacked by the bark beetleTomicus piniperda (L.) were baited with ethanol and α-pinene to attract antagonistic insects and thereby enhance their detrimental effects on the production of bark beetle progeny. Unbaited and caged bolts were included in the experiments as controls. Attraction of beetles to the bolts and subsequent emergence were estimated using traps. Six phloem-feeding species (potential competitors ofT. piniperda) and four predatory species were caught in significantly higher numbers at the baited bolts than at the unbaited ones. The number of offspring and the productivity ofT. piniperda were four to seven times higher in unbaited bolts than in baited bolts. Exclusion of other insects, by using cages, resulted in a nine-fold increase in the number ofT. piniperda offspring per square meter and productivity (offspring per egg gallery) compared with unbaited, exposed bolts.Hylurgops palliatus (Gyll.) (Scolytidae) andRhagium inquisitor (L.) (Cerambycidae) attacked both the baited and unbaited bolts, whereasAcanthocinus aedilis (L.) (Cerambycidae) andPytho depressus (L.) (Pythidae) reproduced almost exclusively in the baited ones. Large numbers of larvae ofThanasimus (Cleridae) andRhizophagus (Rhizophagidae) emerged from both the baited and unbaited bolts. Adults ofPlegaderus vulneratus (Panzer) andCylister linearis (Er.) (Histeridae) emerged almost exclusively from the baited bolts. The low progeny production ofT. piniperda in the baited bolts was attributed largely to the influence of adults ofRhizophagus andEpuraea (Nitidulidae), and larvae ofThanasimus andA. aedilis.
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    URL: http://dx.doi.org/10.1007/BF02059871
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    Male-produced aggregation pheromone ofCarpophilus obsoletus (Coleoptera: Nitidulidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1483-1493 
    Details
    ISSN: 1573-1561
    Keywords: Carpophilus obsoletus ; sap beetle ; Coleoptera ; Nitidulidae ; aggregation pheromone ; hydrocarbon ; tetraene ; date
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Males ofCarpophilus obsoletus Erichson produce an aggregation pheromone to which both sexes respond. The pheromone was identified by GC-MS as (2E,4E,6E,8E)-3,5,7-trimethyl-2,4,6,8-undecatetraene (1), which is also a minor constituent of the pheromone blends ofC. hemipterus (L.),C. freemani Dobson, andC. lugubris Murray. The pheromone was synergized in wind-tunnel bioassays by propyl acetate, a “host-type” coattractant. In a dose-response study, 50 pg of1, plus propyl acetate, was significantly more attractive than just propyl acetate. Pheromone emission from groups of 65 males, feeding on artificial diet, averaged 2.2 ng/male/day. Emissions from individual males were larger, averaging 72 ng/day and ranging as high as 388 ng/day. Synthetic1 was tested in a date garden in southern California (500 µg/rubber septum), using fermenting whole-wheat bread dough as the coattractant. The pheromone plus dough attracted significantly more beetles than dough alone (means were 4.2 and 0.0 beetles per week per trap). Captured beetles were 54% females. Field trap catches were highest during the months of July and August.
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    URL: http://dx.doi.org/10.1007/BF02059874
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    Identification and synthesis of female sex pheromone of Oriental beetle,Anomala orientalis (Coleoptera: Scarabaeidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2415-2427 
    Details
    ISSN: 1573-1561
    Keywords: Anomala orientalis ; Oriental beetle ; Coleoptera ; Scarabaeidae ; sex pheromone ; (Z)- and (E)-7-tetradecen-2-one ; DMDS derivatization ; flight tunnel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Females of the Oriental beetle,Anomala orientalis (Waterhouse), release a sex pheromone composed of a 9:1 blend of (Z)- and (E)-7-tetradecen-2-one. The double-bond position of the pheromone was determined by DMDS derivatization and interpretation of the fragmentation patterns produced by monounsaturated ketones. In a sustained-flight tunnel, males responded by flying toward female beetles and attempting to copulate with them. Both effluvium and whole-body extracts of OB females were analyzed, and the activity was found only in the airborne extracts. Flight-tunnel bioassays also showed that a synthetic 90:10Z/E blend on a rubber septum was attractive and that the responses of males to this blend were equivalent toZ isomer alone, but much better than to the singleE isomer.
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    URL: http://dx.doi.org/10.1007/BF02033210
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    Modification of carbonic anhydrase activity by antisense and over-expression constructs in transgenic tobacco (1994)
    Springer
    Plant molecular biology 25 (1994), S. 377-385 
    Details
    ISSN: 1573-5028
    Keywords: carbonic anhydrase ; antisense ; over-expression ; tobacco ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The activity and location of carbonic anhydrase has been modified by transformation of tobacco with antisense and over-expression constructs. Antisense expression resulted in the inhibition of up to 99% of carbonic anhydrase activity but had no significant impact on net CO2 assimilation. Stomatal conductance and susceptibility to water stress appeared to increase in response to the decline in carbonic anhydrase activity. An over-expression construct designed to increase cytosolic carbonic anhydrase abundance resulted in a significant increase in net activity, a small increase in stomatal conductance but little impact on CO2 assimilation. Chloroplastic carbonic anhydrase activity was enhanced by the expression of an additional construct which targeted the polypeptide to the organelle. The increase in chloroplastic carbonic anhydrase appeared to be accompanied by a concomitant increase in Rubisco activity.
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    URL: http://dx.doi.org/10.1007/BF00043867
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    Over-production of the D1 protein of photosystem II reaction centre in the cyanobacterium Synechococcus sp. PCC 7942 (1994)
    Springer
    Plant molecular biology 26 (1994), S. 709-721 
    Details
    ISSN: 1573-5028
    Keywords: gene expression ; photosynthesis ; protein turnover ; psbA ; tac promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The unicellular cyanobacterium Synechococcus sp. PCC 7942 has three psbA genes encoding two different forms of the photosystem II reaction centre protein D1 (D1:1 and D1:2). The level of expression of these psbA genes and the synthesis of D1:1 and D1:2 are strongly regulated under varying light conditions. In order to better understand the regulatory mechanisms underlying these processes, we have constructed a strain of Synechococcus sp. PCC 7942 capable of over-producing psbA mRNA and D1 protein. In this study, we describe the over-expression of D1:1 using a tac-hybrid promoter in front of the psbAI gene in combination with lacI Q repressor system. Over-production of D1:1 was induced by growing cells for 12 h at 50 μmol photons m-2 s-1 in the presence of 40 or 80 μg/ml IPTG. The amount of psbAI mRNA and that of D1:1 protein in cells grown with IPTG was three times and two times higher, respectively. A higher concentration of IPTG (i.e., 150 μg/ml) did not further increase the production of the psbAI message or D1:1. The over-production of D1:1 caused a decrease in the level of D1:2 synthesised, resulting in most PSII reaction centres containing D1:1. However, the over-production of D1:1 had no effect on the pigment composition (chlorophyll a or phycocyanin/number of cells) or the light-saturated rate of photosynthesis. This and the fact that the total amounts of D1 and D2 proteins were not affected by IPTG suggest that the number of PSII centres within the membranes remained unchanged. From these results, we conclude that expression of psbAI can be regulated by using the tac promoter and lacI Q system. However, the accumulation of D1:1 protein into the membrane is regulated by the number of PSII centres.
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    Iron deprivation in cyanobacteria (1994)
    Springer
    Journal of applied phycology 6 (1994), S. 199-210 
    Details
    ISSN: 1573-5176
    Keywords: cyanobacteria ; iron deficiency ; photosynthesis ; siderophores ; flavodoxin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Iron is an essential component of electron transport in almost all living organisms. It is particularly important to phototrophs like cyanobacteria because 22–23 irons are required for a complete functional photosynthetic apparatus. Since the low solubility of Fe+++ above neutral pH in oxic ecosystems severely limits the biological availability of iron to aquatic microorganisms, cyanobacteria and other microbes have developed a number of responses to cope with iron deficiency. Cyanobacterial responses to iron stress include the synthesis of an efficient, siderophore-based system to scavenge iron and the substitution of ferredoxin with flavodoxin. An additional response in cyanobacteria involves the alteration of the light-harvesting apparatus that includes the appearance of a new, iron-stress-induced, photosystem II, chlorophyll-binding protein. Although cytochromec-553 has a potential non-iron-containing replacement in plastocyanin, a copper-containing protein, iron stress appears to favor the utilization of cytochromec-553 because siderophores also bind copper and form a complex that is excluded from the cell. This paper is intended primarily as a review of molecular and physiological responses of actively growing cyanobacterial cultures to conditions of iron stress, where iron is present but essentially insoluble, and to differentiate these responses from iron starvation, where the amount of iron in the system is not sufficient for cell growth.
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    Use of chlorophyll fluorescence to estimate the effect of photoinhibition in outdoor cultures ofSpirulina platensis (1994)
    Springer
    Journal of applied phycology 6 (1994), S. 31-34 
    Details
    ISSN: 1573-5176
    Keywords: fluorescence ; photoinhibition ; photosynthesis ; Spirulina ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Chlorophyll fluorescence measurements were used to evaluate the effect of temperature on photoinhibition inSpirulina platensis cultures grown in tubular reactors outdoors. Cultures grown at 35 °C during the day time showed a lower reduction in the Fv/Fm ratio as compared to cultures grown at 25 °C. It is demonstrated that the lower temperature photoinhibited cells can undergo a complete recovery once transferred to low light and higher temperature. This recovery does not take place when 100 µg ml-1 chloramphenicol is added to cells. The recovery is light dependent and cells incubated in the dark at low temperature do not show a recovery in the Fv/Fm ratio. The data presented strongly support the hypothesis that photoinhibition takes place in outdoorSpirulina cultures. At the same time it is demonstrated that fluorescence measurements can be used as a fast reliable indication for photoinhibition in outdoor algal cultures.
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    Use of macroalgae for marine biomass production and CO2 remediation: a review (1994)
    Springer
    Journal of applied phycology 6 (1994), S. 45-60 
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    ISSN: 1573-5176
    Keywords: biofilter ; biofuels ; CO2 ; macroalgae ; marine biomass ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Biomass production from macroalgae has been viewed as important mainly because of the need for pollution abatement. Environmental considerations will increasingly determine product and process acceptability and drive the next generation of economic opportunity. Some countries, including Japan, are actively promoting "green" technologies that will be in demand worldwide in the coming decades. Should an international agreement on CO2-reduction be ratified, its effective use for energy production would be of high priority. This report shows that macroalgae have great potential for biomass production and CO2 bioremediation. Macroalgae have high productivity, as great or greater than the most productive land plants, and do not compete with terrestrial crops for farm land. The review focuses on recent data on productivity, photosynthesis, nutrient dynamics, optimization and economics. Biomass from macroalgae promises to provide environmentally and economically feasible alternatives to fossil fuels. Nevertheless, the techniques and technologies for growing macroalgae on a large-scale and for converting feedstocks to energy carriers must be more fully developed.
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    URL: http://dx.doi.org/10.1007/BF02185904
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    What kind of lamp for the cultivation of algae? (1994)
    Springer
    Journal of applied phycology 6 (1994), S. 309-313 
    Details
    ISSN: 1573-5176
    Keywords: light source ; emission spectrum ; photosynthesis ; algae ; absorption ; efficiency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A method for quantitative evaluation of light sources from the point of their suitability for algal cultivation is described. Two parameters are used for the evaluation: (1) amount of photons emitted in the spectral region absorbed by algae per consumed unit of electrical energy; (2) fraction of photons intercept by the algae that got effectively transformed into chemical energy. The value of parameter (2) depends on the emission spectrum of the light source, the absorption spectrum of the algae, quantum capacity of the algae and on conditions of cultivation. The method permits the assessment of the differences in algal productivity under light of various light sources with respect to other recent methods for comparison.
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    URL: http://dx.doi.org/10.1007/BF02181944
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    Turbulence in mass algal cultures and the role of light/dark fluctuations (1994)
    Springer
    Journal of applied phycology 6 (1994), S. 331-335 
    Details
    ISSN: 1573-5176
    Keywords: turbulence ; photosynthesis ; Chlorella ; light/dark cycles ; mass transfer rates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In mass algal cultures, some form of agitation is usually provided; among other effects, this moves the organisms though an optically dense profile and provides mixing. During this transport, medium frequency fluctuations in the light energy supply are perceived by the algae, which are of the order of 1 Hz and less. It has been suggested that turbulence with the resultant light/dark cycles of medium frequency enhances productivity. However, turbulence has two major influences in a well mixed system: it facilitates fluctuating light regimes and increases the transfer rates between the growth medium and the cultured organism. An estimation of productivity as oxygen liberation was measured under laminar and turbulent flow rates, and varying light/dark ratios. Increased turbulence, which increased exchange rates of nutrients and metabolites between the cells and their growth medium, together with increased light/dark frequencies, increased productivity and photosynthetic efficiency.
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    URL: http://dx.doi.org/10.1007/BF02181947
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    Reproductive biology ofFrangula alnus (Rhamnaceae) in southern Spain (1994)
    Springer
    Plant systematics and evolution 193 (1994), S. 173-186 
    Details
    ISSN: 1615-6110
    Keywords: Rhamnaceae ; Frangula ; Diptera ; Coleoptera ; Hymenoptera ; Mecoptera ; Breeding system ; phenology ; pollination biology ; protandry ; reproductive success ; self-incompatibility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Various aspects of the reproductive biology of the perennial hermaphroditeFrangula alnus Mill. were studied in two populations located in the province of Cádiz, southern Spain. Flowering extends from the second week of May to early July. The small, whitegreenish, entomophilous flowers are incompletely protandrous and last 8–10 days, but pollen transfer takes place only on days 1–3. A very weak, pleasant odour along with nectar and pollen attract over 45 insect species, of which 21 are probable pollinators. These are mainlyDiptera but also includeHymenoptera and the unusual (as flower visitors)Mecoptera. Reproduction is exclusively sexual and strictly xenogamous, with pollen transfer depending solely on insect vectors. Although flower morphology and individual flower phenology do not fully prevent self-pollination, and geitonogamy can easily take place, the level of autogamy was negligible. Therefore, some self-incompatibility mechanism is operative in this species. Only 2.8% of open-pollinated flowers set fruit. At the flower level, fruit initiation was apparently limited by availability of cross-pollen, which in turn seemed influenced by the structure of the population. The seed/ovule ratio in ripe fruits was ca. 50%. Predispersal (maternal) reproductive success (percent ovules becoming filled seeds) was 1.42%. For mature individuals this corresponded to ca. 430 to 1560 potential offspring per year.
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    Analysis of divergence of Alphitobius diaperinus satellite DNA — roles of recombination, replication slippage and gene conversion (1994)
    Springer
    Molecular genetics and genomics 242 (1994), S. 297-304 
    Details
    ISSN: 1617-4623
    Keywords: Repetitive sequences ; Sequence variability ; Satellite DNA evolution ; Coleoptera ; X70332
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Satellite DNA is highly abundant in Alphitobius diaperinus (Tenebrionidae, Coleoptera), comprising 25% of the total genomic DNA. Sequence analysis reveals an average GC content of 50.8% and the presence of three different groups of satellite monomer variants, tH1, tH2 and tH3 with corresponding lengths of 123, 128 and 126 bp. Their mutual homologies range between 65 and 81 %. Sequence comparison shows that the monomer variant tH2 has been formed by a recombination process between tH1 and tH3, which have a low average homology of only 65.15%. The longest stretch of 100% homology between the recombining units is 17 bp and is located 3′ to the predicted recombination site. There is also an indication from sequence analysis that replication slippage and gene conversion play a part in the formation of satellite units and contribute to their divergence. The tH1, tH2 and tH3 monomer variants are organized in higher order repeating structures: a dimer, composed of tH1, and tH3, and a trimer containing tH1, tH2 and tH3 in series. The dimeric and trimeric repeat units furthermore create three higher order satellite subfamilies. Two of them contain either tandemly arranged dimers or trimers, while the third one is composed of both types of repeats, mutually interspersed.
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    Genetic variation in pigeon pea (Cajanus cajan (L.) Mill sp.) in response to successive cycles of water stress (1994)
    Springer
    Plant and soil 158 (1994), S. 193-201 
    Details
    ISSN: 1573-5036
    Keywords: photosynthesis ; osmotic adjustment ; stomatal conductance ; relative water content ; water potential ; water relations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Four pigeon pea [Cajanus cajan (L.) Mill sp.] cultivars were studied during two cycles of development of water stress and recovery. During these two cycles the genetic variation in vegetative development, leaf water potential, relative water content, photosynthesis, and stomatal conductance was followed. Plants were grown in a greenhouse and irrigated every seventh day. On two occasions (30 days and 80 days from sowing) water was withheld for 13 days in one group of plants and 16 days in another. Control plants were irrigated as usual. The four cultivars differed in their response to drought, with ICPL 215 being the most tolerant cultivar. In the plants exposed to the 13-day water stress, the first stress cycle resulted in preconditioning of plants such that higher values for carbon dioxide exchange rate and relative water content were observed in the second stress cycle. The longer stress period (16 days) resulted in some damage to the photosynthetic capacity and in a slow recovery rate in both cycles. During the second drought cycle the plants retained a water content above the critical value, possibly due to osmotic adjustment. It seems that water status parameters, especially relative water content, may serve as indicators of drought tolerance in pigeon pea varieties and may be useful in breeding programs for cultivation of pigeon pea under semiarid conditions.
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    Model studies of chlorophyll fluorescence reabsorption at chloroplast level under different exciting conditions (1994)
    Springer
    Photosynthesis research 40 (1994), S. 67-74 
    Details
    ISSN: 1573-5079
    Keywords: light conditions ; theoretical model ; barley leaf ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A theoretical model is presented describing the distortion of chlorophyll fluorescence spectra of a chloroplast or a group of chloroplasts by the effect of fluorescence reabsorption. Model calculations using the experimental data show that the primary reabsorption effect occurs already within one chloroplast and the spectral distortion depends significantly on the excitation regime of the chloroplast. A theoretical dependence of the distortion function, defined as a change in the F(685)/F(735) fluorescence band ratio, on the mean chlorophyll concentration in a chloroplast is predicted for different light excitation regimes. The distortion of measured chlorophyll fluorescence spectra at 77 K of chloroplast suspension adsorbed on filter papers of two strongly different diffusive reflectivities and at different mean chlorophyll concentrations are discussed with the help of the presented theory.
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    UV-B damage and protection at the molecular level in plants (1994)
    Springer
    Photosynthesis research 39 (1994), S. 475-489 
    Details
    ISSN: 1573-5079
    Keywords: DNA repair ; flavonoids ; gene expression ; oxidative stress ; photosynthesis ; promoter
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Influx of solar UV-B radiation (280–320 nm) will probably increase in the future due to depletion of stratospheric ozone. In plants, there are several targets for the deleterious UV-B radiation, especially the chloroplast. This review summarizes the early effects and responses of low doses of UV-B at the molecular level. The DNA molecules of the plant cells are damaged by UV due to the formation of different photoproducts, such as pyrimidine dimers, which in turn can be combatted by specialized photoreactivating enzyme systems. In the chloroplast, the integrity of the thylakoid membrane seems to be much more sensitive than the activities of the photosynthetic components bound within. However, the decrease of mRNA transcripts for the photosynthetic complexes and other chloroplast proteins are among very early events of UV-B damage, as well as protein synthesis. Other genes, encoding defence-related enzymes, e.g., of the flavonoid biosynthetic pathway, are rapidly up-regulated after commencement of UV-B exposure. Some of the cis-acting nucleotide elements and trans-acting protein factors needed to regulate the UV-induced expression of the parsley chalcone synthase gene are known.
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    Photosynthetic electrogenic events in native membranes ofChloroflexus aurantiacus. Flash-induced charge displacements within the reaction center-cytochromec 554 complex (1994)
    Springer
    Photosynthesis research 41 (1994), S. 135-143 
    Details
    ISSN: 1573-5079
    Keywords: photosynthesis ; electrometry ; membrane potential ; electron transfer ; charge displacement ; electrostatic ; Chloroflexus aurantiacus ; Rhodopseudomonas viridis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The thermophilic phototrophChloroflexus aurantiacus possesses a photosynthetic reaction center (RC) containing a pair of menaquinones as primary (QA) and secondary (QB) electron acceptors and a bacteriochlorophyll dimer (P) as a primary donor. A tetraheme cytochromec 554 with two high(H)- and two low(L)-potential hemes operates as an immediate electron donor for P. The following equilibrium Em,7 values were determined by ESR for the hemes in whole membrane preparations: 280 mV (H1), 150 mV (H2), 95 mV (L1) and 0 mV (L2) (Van Vliet et al. (1991) Eur. J. Biochem. 199: 317–323). Partial electrogenic reactions induced by a laser flash inChl. aurantiacus chromatophores adsorbed to a phospholipid-impregnated collodion film were studied electrometrically at pH 8.3. The photoelectric response included a fast phase of ΔΨ generation (τ 〈 10 ns, phase A). It was ascribed to the charge separation between P+ and QA − as its amplitude decreased both at high and low Eh values (Em,high=360±10 mV, estimated Em,low∼\s-160 mV) in good agreement with Em values for P/P+ and QA/QA − redox couples. A slower kinetic component appeared upon reduction of the cytochromec 554 hemes (phase C). With H1 reduced before the flash the amplitude of phase C was equal to 15–20% of that of phase A and its rise time was 1.2–1.3 μs: we attribute this phase to the electrogenic electron transfer from H1 to P+. Pre-reduction of H2 decreased the τ value to about 700–800 ns and increased the amplitude of phase C to 30–35% of that of phase A. Pre-reduction of L1 further accelerated phase C (up to τ of 500 ns) and induced a reverse electrogenic phase with τ of 12 μs and amplitude equal to 10% of phase A. Upon pre-reduction of L2 the rise time of phase C was decreased to about 300 ns and its amplitude decreased by 30%. The acceleration in the onset of phase C is explained by the acceleration of the rate-limiting H1 ⇒ P electrogenic reaction after reduction of the other hemes due to their electrostatic influence; a P-H1-(L1-L2)-H2 alignment of redox centers with an approximately rhombic arrangement of the cytochromec 554 hemes is proposed. The observed reverse phase is ascribed to the post-flash charge redistribution between the hemes. Redox titration of the amplitude of phase C yielded the Em,8.3 values of H1, H2 and L2 hemes: 340±10 mV for H1, 160±20 mV for H2 and −40±40 mV for L2.
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    Pigment interactions in chlorosomes of various green bacteria (1994)
    Springer
    Photosynthesis research 41 (1994), S. 175-180 
    Details
    ISSN: 1573-5079
    Keywords: Chlorobium ; Chloroflexus ; chlorophyll ; light-harvesting ; photosynthesis ; resonance Raman
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Resonance Raman experiments were performed on different green bacteria. With blue excitation, i.e. under Soret resonance or preresonance conditions, resonance Raman contributions were essentially arising from the chlorosome pigments. By comparing these spectra and those of isolated chlorosomes, it is possible to evaluate how the latter retain their native structure during the isolation procedures. The structure of bacteriochlorophyll oligomers in chlorosomes was interspecifically compared, in bacteriochlorophyllc- and bacteriochlorophylle- synthesising bacteria. It appears that interactions assumed by the 9-keto carbonyl group are identical inChlorobium limicola, Chlorobium tepidum, andChlorobium phaeobacteroides. In the latter strain, the 3-formyl carbonyl group of bacteriochlorophylle is kept free from intermolecular interactions. By contrast, resonance Raman spectra unambiguously indicate that the structure of bacteriochlorophyll oligomers is slightly different in chlorosomes fromChloroflexus auranticus, either isolated or in the whole bacteria.
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    The formation and characterization of the in vitro polymeric aggregates of bacteriochlorophyllc homologs fromChlorobium limicola in aqueous suspension in the presence of monogalactosyl diglyceride (1994)
    Springer
    Photosynthesis research 41 (1994), S. 235-243 
    Details
    ISSN: 1573-5079
    Keywords: bacteriochlorophyll ; chlorosomeChlorobium limicola ; green bacteria ; photosynthesis ; monogalactosyl diglyceride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Artificial aggregates of bacteriochlorophyllc (BChlc) were formed in an aqueous medium in the presence of a lipid, monogalactosyl diglyceride (MGDG), and the optical properties of those aggregates were studied by absorption and circular dichroism (CD) mainly. Four BChlc homologs, ([E,E]BChlc F, [P,E]BChlc F, [E,M]BChlc F and [I,E]BChlc F), were isolated from the green photosynthetic bacteriumChlorobium limicola strain 6230. Above 0.0004%, MGDG induced a red-shift of the absorption maxima of BChlc aggregates. At 0.003% MGDG BChlc aggregates showed absorption maxima in the range of 724 to 745 (±3) nm with a shift of 12 to 24 (±3) nm depending on the homolog species. Four kinds of BChlc-MGDG aggregates showed characteristic CD spectra. [E,M]BChlc F gave rise to a CD spectrum similar to that of chlorosomes, while the other three gave spectra of opposite sign. These aggregates are sensitive to 1-hexanol treatment; in a saturating amount (0.85%) of 1-hexanol, all the homologs gave a monomer-like absorption spectrum peaking at 670nm. At an intermediate concentration (0.5%), [E,M]BChlc F showed an enhanced CD intensity, as observed in native chlorosomes. Resonance Raman spectra of the monomer-like BChlc samples indicated that the keto vibrational band at ca. 1640 cm−1 was considerably weakened by the 0.85% 1-hexanol treatment, however the 1680 cm−1 band characteristic of a free keto group did not appear. These results indicate that the artificial aggregates formed by purified BChlc homologs and MGDG are good models for studying chlorosomes structure.
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    Sensitivity of the relative Fpl level of chlorophyll fluorescence induction in leaves to the heat stress (1994)
    Springer
    Photosynthesis research 39 (1994), S. 201-204 
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    ISSN: 1573-5079
    Keywords: automatic determination ; fluorescence parameters ; fluorometer ; induction curve ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The (Fpl-Fo)/Fv value of the fluorescence induction curve is shown to be a more suitable parameter to detect a wider range of heat stress damage to thylakoid membranes as compared to quantities t 1/2 (time of fluorescence rise from Fo to (Fo+Fm)/2 level) and % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0Jf9crFfpeea0xh9v8qiW7rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaacq% aHepaDaaaaaa!39D5!\[\overline \tau \] (the fluorescence induction time defined as the area above the induction curve normalized to Fv=1). A method for exact and automatic Fpl determination is presented. A break point in the quality and behaviour of the fluorescence induction curve of barley leaves incubated at 49°C was reached at the moment (about 240 s) when the transformation of PS II active (QB-reducing) to PS II inactive (QB-non-reducing) centres was completed. The meaning of the standard Fv and Fv/Fm parameter was then changed. The method of Fpl determination described here may help to increase the analytical value of the standard chlorophyll fluorometers.
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    The role of iron in phytoplankton photosynthesis, and the potential for iron-limitation of primary productivity in the sea (1994)
    Springer
    Photosynthesis research 39 (1994), S. 275-301 
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    ISSN: 1573-5079
    Keywords: chlorosis ; diagnostic ; flavodoxin ; iron-limitation ; photosynthesis ; phytoplankton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Iron supply has been suggested to influence phytoplankton biomass, growth rate and species composition, as well as primary productivity in both high and low NO3 − surface waters. Recent investigations in the equatorial Pacific suggest that no single factor regulates primary productivity. Rather, an interplay of bottom-up (i.e., ecophysiological) and top-down (i.e., ecological) factors appear to control species composition and growth rates. One goal of biological oceanography is to isolate the effects of single factors from this multiplicity of interactions, and to identify the factors with a disproportionate impact. Unfortunately, our tools, with several notable exceptions, have been largely inadequate to the task. In particular, the standard technique of nutrient addition bioassays cannot be undertaken without introducing artifacts. These so-called ‘bottle effects’ include reducing turbulence, isolating the enclosed sample from nutrient resupply and grazing, trapping the isolated sample at a fixed position within the water column and thus removing it from vertical movement through a light gradient, and exposing the sample to potentially stimulatory or inhibitory substances on the enclosure walls. The problem faced by all users of enrichment experiments is to separate the effects of controlled nutrient additions from uncontrolled changes in other environmental and ecological factors. To overcome these limitations, oceanographers have sought physiological or molecular indices to diagnose nutrient limitation in natural samples. These indices are often based on reductions in the abundance of photosynthetic and other catalysts, or on changes in the efficiency of these catalysts. Reductions in photosynthetic efficiency often accompany nutrient limitation either because of accumulation of damage, or impairment of the ability to synthesize fully functional macromolecular assemblages. Many catalysts involved in electron transfer and reductive biosyntheses contain iron, and the abundances of most of these catalysts decline under iron-limited conditions. Reductions of ferredoxin or cytochrome f content, nitrate assimilation rates, and dinitrogen fixation rates are amongst the diagnostics that have been used to infer iron limitation in some marine systems. An alternative approach to diagnosing iron-limitation uses molecules whose abundance increases in response to iron-limitation. These include cell surface iron-transport proteins, and the electron transfer protein flavodoxin which replaces the Fe-S protein ferredoxin in many Fe-deficient algae and cyanobacteria.
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    Molecular topology of the Photosystem II chlorophyll a binding protein, CP 43: Topology of a thylakoid membrane protein (1994)
    Springer
    Photosynthesis research 40 (1994), S. 11-19 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; membrane protein ; protein structure ; light harvesting
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have used antibodies generated against synthetic peptides to determine the topology of the 43 kD chlorophyll a binding protein (CP 43) of Photosystem II. Based on the pattern of proteolytic fragments detected (on western blots) by peptide specific antibodies, a six transmembrane span topological model, with the amino and carboxyl termini located on the stromal membrane surface, is predicted. This structure is similar to that predicted for CP 47, a PS II chlorophyll a binding protein (Bricker T (1990) Photosynth Res 24: 1–13). The model is discussed in reference to the possible location of chlorophyll binding sites.
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  • 40
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    The Wageningen Rhizolab — a facility to study soil-root-shoot-atmosphere interactions in crops (1994)
    Springer
    Plant and soil 161 (1994), S. 275-287 
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    ISSN: 1573-5036
    Keywords: crop growth ; gas exchange ; minirhizotrons ; nutrients ; photosynthesis ; respiration ; rhizotron ; root observation ; root growth ; water balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A research facility is described for the integrated study of soil-root-shoot-atmosphere relationships in crops. The Wageningen Rhizolab has been in use since 1990, and consists of two rows, each with eight below-ground compartments aligned along a corridor. A rain shelter automatically covers the experimental area at the start of rainfall. Compartments are 125 cm × 125 cm and 200 cm deep. Each compartment has a separate drip irrigation system. Crop canopy photosynthesis, respiration, and transpiration can be measured simultaneously and continuously on four out of eight compartments at a time. Each compartment can be filled with a selected soil material (repacked soil) and is accessible from the corridor over its full depth. Multiple sensors for measuring soil moisture status, electrical conductivity, temperature, soil respiration, trace gases and oxygen are installed in spatial patterns in accordance with the requirements of the experiments. Sensors are connected to control and data-acquisition devices. Likewise, provisions have been made to sample manually the soil solution and soil atmosphere. Root observation tubes (minirhizotrons) are installed horizontally at depth intervals ranging from 5 cm (upper soil layers) to 25 cm (below 1 m). The facility is at present in use to study growth and development of vegetation (crops) in relation to drought, nutrient status, soil-borne diseases, and underground root competition. One important application is the study of elevated CO2 concentration and climate change and the way they affect crops and their carbon economy. Growth and development of field grown vegetables and winter cover crops are also evaluated. The common aspect of those studies is to gain a better understanding of crop growth under varying environmental conditions, and to collect datasets that may help to improve mechanistic crop growth simulation models that can address suboptimal growth conditions.
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    Effects of nitrogen supply on the acclimation of photosynthesis to elevated CO2 (1994)
    Springer
    Photosynthesis research 39 (1994), S. 389-400 
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    ISSN: 1573-5079
    Keywords: elevated CO2 ; nitrogen supply ; photosynthesis ; acclimation ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A common observation in plants grown in elevated CO2 concentration is that the rate of photosynthesis is lower than expected from the dependence of photosynthesis upon CO2 concentration in single leaves of plants grown at present CO2 concentration. Furthermore, it has been suggested that this apparent down regulation of photosynthesis may be larger in leaves of plants at low nitrogen supply than at higher nitrogen supply. However, the available data are rather limited and contradictory. In this paper, particular attention is drawn to the way in which whole plant growth response to N supply constitutes a variable sink strength for carbohydrate usage and how this may affect photosynthesis. The need for further studies of the acclimation of photosynthesis at elevated CO2 in leaves of plants whose N supply has resulted in well-defined growth rate and sink activity is emphasised, and brief consideration is made of how this might be achieved.
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    The influence of ammonia on the growth and photosynthesis of Ruppia drepanensis Tineo from Doñana National Park (SW Spain) (1994)
    Springer
    Hydrobiologia 275-276 (1994), S. 219-231 
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    ISSN: 1573-5117
    Keywords: Ruppia drepanensis ; ammonia toxicity ; temperature effects ; photosynthesis ; growth
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In a laboratory experiment, Ruppia drepanensis Tineo seedlings from a brackish marsh in Southern Spain were grown at 20 and 30 °C, at three different nitrogen levels. These levels were obtained by the addition of a slow release fertilizer (23% NH4NO3 by weight) to a sediment mixture of sand and clay (3:1). Several morphometric parameters were recorded during the first five weeks of the experiment, and photosynthesis and respiration were measured after 7 weeks of growth. Results showed a significant reduction of growth and development with increasing nitrogen and temperature levels. Dark respiration increased strongly at high nitrogen levels. At the same time, net photosynthesis at 250 and 500 µE m-2 s-1, Pm, Km and LCP were not affected by either factor. We attribute these phenomena to ammonia toxicity, since relatively high total ammonia (NH3 + NHf4 p+) levels were found in the interstitial water.
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    Environmental control of phytoplankton productivity in turbulent turbid systems (1994)
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    Hydrobiologia 289 (1994), S. 65-72 
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    ISSN: 1573-5117
    Keywords: photosynthesis ; selective environments ; resuspension ; disturbance ; rivers ; shallow lakes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Factors affecting phytoplankton productivity are analysed in turbid systems, such as shallow lakes and rivers. When resuspension from the sediment or loading from the catchment significantly increases inorganic (non-algal) turbidity and hence light attenuation potentials for high production are not realised. Energy available for phytoplankton growth is strongly regulated by underwater light availability which depends on the critical mixing depth, fluctuating light intensities and algal circulation patterns. Higher production rates in shallow waters are often compensated by greater algal respiration due to higher water temperatures when compared to deeper lakes. Total daily integral production of turbulent, turbid environments can be predicted from a combination of easily measured variables such as maximum photosynthetic rates, algal biomass, surface irradiance and some measure of underwater light attenuation.
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    Effects of homobrassinolide application on plant metabolism and grain yield under irrigated and moisture-stress conditions of two wheat varieties (1994)
    Springer
    Plant growth regulation 14 (1994), S. 173-181 
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    ISSN: 1573-5087
    Keywords: homobrassinolide ; irrigated ; membrane stability ; moisture-stress ; nitrate reductase activity ; photosynthesis ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Homobrassinolide (BR) was applied either as a seed treatment or foliar spray to two contrasting wheat varieties, viz. C306 (drought tolerant) and HD2329 (drought susceptible), to examine its effects on plant metabolism and grain yield under irrigated and moisture-stress/rainfed conditions. BR application resulted in increased relative water content, nitrate reductase activity, chlorophyll content and photosynthesis under both conditions. BR application also improved membrane stability (lower injury). These beneficial effects resulted in higher leaf area, biomass production, grain yield and yield related parameters in the treated plants. All the treatments were significantly better than the untreated control. Generally, 0.05 ppm either as a seed treatment or foliar spray was more effective than the 0.01 ppm treatment. The drought-tolerant genotype C306 showed more response to BR application under moisture-stress/rainfed condition than HD 2329. Increased water uptake, membrane stability and higher carbon dioxide and nitrogen assimilation rates under stress seemed to be related to homobrassinolide-induced drought tolerance.
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    Development and ecological importance of phytoplankton in a large lowland river (River Meuse, Belgium) (1994)
    Springer
    Hydrobiologia 289 (1994), S. 139-155 
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    ISSN: 1573-5117
    Keywords: potamoplankton ; regulated river ; transport of carbon and nutrients ; photosynthesis ; respiration ; dynamics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ecological importance of the River Meuse phytoplankton with regard to carbon and nutrient transport has been examined in two reaches of the Belgian course of the river. Field measurements of total particulate organic carbon (POC), particulate organic nitrogen (PON) and particulate phosphorus (PP) show that the large autochtonous production of organic matter strongly affects the carbon and nutrient budget of the aquatic system. During the growing season, phytoplankton accounts for nearly 60% of the POC and dominates the PON. Calculations of the carbon and oxygen budget in the upper reach of the Belgian Meuse demonstrates that the ecosystem is autotrophic, i.e. that autochtonous FPOM (fine particulate organic matter) production is the major carbon input. This suggests that in large lowland rivers, primary production (P) may exceed community respiration (R), i.e. P:R〉1, whereas they are assumed to be heterotrophic (P:R〈1) in the River Continuum concept. The question of maintenance of phytoplankton in turbid mixed water columns is also addressed, and the case of the River Meuse is treated on the basis of studies of photosynthesis and respiration (ETS measurements). The results suggest that the potamoplankton may show some low-light acclimation, through an increase of chlorophyll a relative to biomass, when it comes to deep downstream reaches, and that algal respiration rate may be reduced. A simulation of the longitudinal development of the algal biomass shows the different phases of algal growth and decline along the river and brings support to the ‘importation hypothesis’ for explaining maintenance of potamoplankton in the downstream reaches.
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    An active Mehler-peroxidase reaction sequence can prevent cyclic PS I electron transport in the presence of dioxygen in intact spinach chloroplasts (1994)
    Springer
    Photosynthesis research 41 (1994), S. 429-437 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; ascorbate peroxidase ; Mehler reaction ; cyclic PS I ; chlorophyll fluorescence ; 9-aminoacridine fluorescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Simultaneous measurements of 9-aminoacridine (9-AA) fluorescence quenching, O2-uptake and chlorophyll fluorescence of intact spinach chloroplasts were carried out to assess the relationship between the transthylakoidal ΔpH and linear electron flux passing through Photosystem II. Three different types of O2-dependent electron flow were investigated: (1) Catalysed by methyl viologen; (2) in the absence of a catalyst and presence of an active ascorbate peroxidase (Mehler-peroxidase reaction); (3) in the absence of a catalyst and with the ascorbate peroxidase being inhibited by KCN (Mehler reaction). The aim of this study was to assess the relative contribution of ΔpH-formation which is not associated with electron flow through Photosystem II and, which should reflect Photosystem I cyclic flow under the different conditions. The relationship between the extent of 9-AA fluorescence quenching and O2-uptake rate was found to be almost linear when methyl viologen was present. In the absence of methyl viologen (Mehler reaction) an increase of 9-AA fluorescence quenching to a value of 20% at low light intensities was associated with considerably less O2-uptake than in the presence of methyl viologen, indicating the involvement of cyclic flow. These findings are in agreement with a preceding study of Kobayashi and Heber (1994). However, when no KCN was added, such that the complete Mehler-peroxidase reaction sequence was operative, the relationship between 9-AA fluorescence quenching and the flux through PS II, as measured via the chlorophyll fluorescence parameter ΔF/Fm′ × PAR, was identical to that observed in the presence of methyl viologen. Under the assumption that methyl viologen prevents cyclic flow, it is concluded that there is no significant contribution of cyclic electron flow to ΔpH-generation in intact spinach chloroplasts.
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    Aggregation pheromones inDryocoetes affaber (Mann.) (Coleoptera: Scolytidae): stereoisomerism and species specificity (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 111-124 
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    ISSN: 1573-1561
    Keywords: Semiochemicals pheromones ; Dryocoetes affaber ; Dryocoetes confusus ; Coleoptera ; Scolytidae ; enantiomers ; diastereoisomers ; exo-brevicomin ; endo-brevicomin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Chemical analysis of whole body extracts and volatiles produced by feeding malesDryocoetes affaber (Mann.) disclosed (+)-exo-brevicomin and (+)-endo-brevicomin [(+)EXOB and (+)ENDOB], as the major insect-produced potential pheromones. Laboratory bioassays and field-trapping experiments demonstrated that (+)ENDOB is the main pheromone component, and (-)ENDOB has an inhibiting effect. EXOB either as (+) or (±) appears to be a multifunctional pheromone. It has a synergistic effect in blends of EXOB and ENDOB in ratios up to 1:1, and it is inhibitory at higher ratios. (-)EXOB was inactive. The most attractive blend forD. affaber was a 1:2 blend of (+)EXOB and (+)ENDOB. When this blend was compared with a 9:1 blend, the best known blend forDryocoetes confusus Swaine, the responses by beetles of each of the two species were highly specific, providing evidence for pheromonal exclusion between the two congenerics. We conclude that the combined effect of chirality and the ratio of geometrical isomers of brevicomin determines both the level of response and the species-specificity of the chemical signal inD. affaber.
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    Comparison of walking locomotory reactions of two forms ofCallosobruchus maculatus males subjected to female sex pheromone stimulation (Coleoptera: Bruchidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2917-2930 
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    ISSN: 1573-1561
    Keywords: Callosobruchus maculatus ; Coleoptera ; Bruchidae ; flightless form ; flight form ; tubular olfactometer ; walking behavior ; intermittent stimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A comparison of the walking locomotory reactions of flightless and flight formCallosobruchus maculatus males when subjected to an air current scented with female sex pheromone was undertaken in a tubular olfactometer. The pheromone was delivered to the males either as short pulses or as a continuous flow. To analyze the males' reactions, three behavioral sequences were defined (sequence 1: male sensitivity/arousal; sequence 2: male reactivity; sequence 3; male progression and source location). Although flightless and flight form males were sensitive and reactive in all experiments, their locomotory displacement differed depending on the stimulus conditions. The flightless form males' response remained roughly the same whatever the stimulus conditions (i.e., they always reached the pheromone source). In contrast, the flight form males displayed a markedly reduced response when subjected to a continuous stimulation, indicating that intermittent on-off pheromone stimulation is required in order to sustain their upwind walking progress. This effect could be the result of sensory adaptation and/or habituation in the central nervous system of the flight form, requiring a flickering signal that is unnecessary for the flightless one.
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    Aggregation pheromone of palmetto weevil,Rhynchophorus cruentatus (F.) (Coleoptera: Curculionidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 505-515 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Curculionidae ; Rhynchophorus cruentatus ; palmetto weevil ; S. palmetto ; aggregation pheromone ; 5-methyl-4-octanol ; cruentol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 5-Methyl-4-octanol is the major aggregation pheromone of the palmetto weevil,Rhynchophorus cruentatus (F.). The pheromone (cruentol) was identified by coupled gas chromatographic-electroantennographic (GC-EAD) analysis of male-produced volatiles, coupled GC-mass spectrometry (MS) in electron impact and chemical ionization mode, and coupled GC-high resolution MS. In laboratory and field assays, a diastereomeric mixture of synthetic cruentol greatly enhanced attraction of weevils to cabbage palmetto,Sabal palmetto (Walter), stem tissue, indicating that cruentol and host volatiles are synergistically attractive. An attractive lure in combination with efficient traps should facilitate development of semiochemical-based management forR. cruentatus.
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  • 50
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    Oxidative responses in soybean foliage to herbivory by bean leaf beetle and three-cornered alfalfa hopper (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 639-650 
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    ISSN: 1573-1561
    Keywords: Soybean ; lipoxygenase ; peroxidase ; polyphenol oxidase ; trypsin inhibitor ; ascorbate oxidase ; oxidative stress ; Lepidoptera ; Noctuidae ; Helicoverpa zea ; corn earworm ; Cerotoma trifurcata ; bean leaf beetle ; Coleoptera ; Chrysomelidae ; Spissistilus festinus ; three-cornered alfalfa hopper ; Homoptera ; Membracidae ; induced resistance ; interspecific competition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Variation in induced responses in soybean is shown to be dependent, in part, upon herbivore species. Herbivory by the phloem-feeding three-cornered alfalfa hopper caused increases in the activities of several oxidative enzymes including lipoxygenases, peroxidases, ascorbate oxidase, and polyphenol oxidase. Bean leaf beetle defoliation caused increased lipoxygenase activity, but had little effect upon peroxidase, polyphenol oxidase, ascorbate oxidase, or trypsin inhibitor levels in either field or greenhouse studies. In one field experiment, prior herbivory by the bean leaf beetle subsequently reduced the suitability of foliage to the corn earwormHelicoverpa zea. The contribution of these findings to emerging theories of insect-plant interactions is discussed.
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    Influence of white pine watering regimes on feeding preferences of spring and fall adults of the white pine weevilPissodes strobi (Peck) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 831-847 
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    ISSN: 1573-1561
    Keywords: Pissodes strobi ; white pine weevil ; Coleoptera ; Curculionidae ; Pinus strobus ; white pine ; plant vigor ; water stress
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Spring and fall adults of the white pine weevil,Pissodes strobi (Peck), were exposed in no-choice and two-choice tests to bark from water-stressed and non-water-stressed white pine (Pinus strobus L.), which had also been exposed or not exposed to weevil attack. This experiment demonstrated that the weevils could discriminate between bark from water-stressed white pine and preferred bark from the nonstressed plants. The weevils also preferred bark from nonstressed plants that were previously exposed to weevil damage. Spring and fall adults displayed the same feeding preferences. No sex differences were found in feeding preferences. Less nitrogen, phosphorus, and potassium were found in bark from the nonstressed plants, and the potassium level was higher in damaged plants. We expect that the biological performance of the weevil should be favored by vigorously growing plants rather than by stressed plants.
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    Identification of branched alkanes in lipids ofLeptinotarsa decemlineata say andTribolium destructor by GC-MS: A comparison of main-beam and link-scanned spectra (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2197-2212 
    Details
    ISSN: 1573-1561
    Keywords: Insects hydrocarbons ; alkanes ; Colorado beetle ; Leptinotarsa decemlineata Say ; Tribolium destructor ; Coleoptera ; Teneboionidae ; choysomelidae ; mass spectrometry ; linked scanning
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Branched hydrocarbons were identified in the lipids ofLeptinotarsa decemlineata Say andTribolium destructor by gas chromatography, ordinary electron impact mass spectrometry, and linked, scanned, daughterion monitoring. This methodology allowed us to revise our earlier results based only on GC-MS data confirming the existence of only monomethyl-, dimethyl-, and trimethylalkanes in the hydrocarbons ofL. decemlineata Say. The hydrocarbons fromTribolium destructor consist ofn-alkanes, 3-methylalkanes, internally branched monomethylalkanes and dimethylalkanes. Daughter-ion monitoring can be particularly important for distinguishing between incidentally overlapped GC peaks of hydrocarbons from different series. A trace, for example, of dimethylalkane coeluating withn-alkane was easily identified in GC peak of hydrocarbon mixture ofT. destructor. Link scans confirmed also molecular weights for the compounds without molecular ions in the mass spectra. Structural assignment of the compounds were verified by comparison of the experimental and calculated values of the GC retention Kovats indexes (KI).
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    Studies on Bacillus thuringiensis strains isolated from Swedish soils: insect toxicity and production of B. cereus-diarrhoeal-type enterotoxin (1994)
    Springer
    World journal of microbiology and biotechnology 10 (1994), S. 406-409 
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    ISSN: 1573-0972
    Keywords: Bacillus cereus-diarrhoeal-type enterotoxin ; Bacillus thuringiensis ; Coleoptera ; Diptera ; Lepidoptera ; thuringiensin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract At moderate concentration, 23 of 40 strains of Bacillus thuringiensis isolated from Sweden were toxic to Trichoplusia ni and five were toxic to Aedes aegypti. Five of the strains were toxic to Diabrotica undecimpunctata at high concentration, two were toxic to Heliothis virescens at low concentration and five produced thuringiensin (formerly called β-exotoxin). No strain was toxic towards the beet armyworm Spodoptera exigua at low concentration. Twenty-three of the strains produced a B. cereus-diarrhoeal-type enterotoxin.
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    Release of ethylene from pruned olive logs: Influence on attack by bark beetles (Coleoptera, Scolytidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2513-2521 
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    ISSN: 1573-1561
    Keywords: Semiochemicals ; kairomones ; ethylene ; ethrel ; Olea europaea ; olive tree ; Phloeotribus scarabaeoides ; Coleoptera ; Scolytidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract In recently pruned olive logs, an increase in ethylene release has been observed between 48 and 72 hr after pruning. The values reached, as well as the duration of ethylene release, varied greatly from one log to another. PioneerPhloeotribus scarabaeoides females have shown a preference for logs in which ethylene emission was higher. In logs treated with ethrel, a significant increase in ethylene emission was observed, together with a greater period of release. Therefore, the use of logs treated with ethrel could be of great importance in the control of this pest of olive trees.
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    2-(E)-nonen-1-ol: Male attractant for chafersAnomala vitis Fabr. andA. dubia Scop. (Coleoptera: Scarabaeidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2481-2487 
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    ISSN: 1573-1561
    Keywords: Anomala vitis ; Anomala dubia ; chafer ; Coleoptera ; Scarabaeidae ; Melolonthidae ; Rutelinae ; attractant ; 2-(E)-nonen-1-ol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Traps baited with 2-(E)-nonen-1-ol alone or in combination with other compounds caught large numbers of males of both the vine chafer,Anomala vitis Fabr. and the margined vine chafer,A. dubia Scop. (Coleoptera: Scarabaeidae), vineyard and orchard pests. In a dosage test, the largest numbers were caught by traps baited with 10 mg of 2-(E)-nonen-1-ol, which was the highest dosage tested. This is the first report on male attractants for chafer species occurring in Europe.
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    Repeatability of female response to ipsdienol enantiomeric mixtures by pine engraver,Ips pini (Coleoptera: Scolytidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2611-2622 
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    ISSN: 1573-1561
    Keywords: Ips pini ; Coleoptera ; Scolytidae ; repeatability ; female choice ; response phenotype ; bark beetle ; pheromone ; communication systems ; multiple measurements ; individual variation ; ipsdienol ; enantiomers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Repeatability, a measure of the proportion of variance in a character that occurs among rather than within individuals, is assessed for the phenotypic trait of female response preference for enantiomeric blends of ipsdienol inIps pini at two pheromone concentrations—1 µg and 5 μg of ipsdienol. Average female response shows greater repeatability at the higher pheromone dosage when females are tested in two successive sets of five assays than when assayed in three successive sets or at the lower dosage. Repeatability within each set of five assays is highest for the first set and decreases thereafter. Thus the response phenotype of females for enantiomeric blends of ipsdienol in this experiment is context dependent; female choice of an enantiomeric blend differed between dosages and among sets of assays.
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    Response ofDendroctonus brevicomis Le Conte (Coleoptera: Scolytidae) to different release rates and ratios of aggregation semiochemicals and the inhibitors verbenone and ipsdienol (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2931-2941 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Dendroctonus brevicomis ; western pine beetle ; aggregation ; verbenone ; ipsdienol ; inhibitors ; antiaggregants ; doseresponse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The response of western pine beetle,Dendroctonus brevicomis Le Conte, to different release rates of the aggregation semiochemicals (attractants)exo-brevicomin, frontalin, and myrcene and the inhibitors verbenone and ipsdienol was investigated. Release rates of verbenone ranging from 0.18 mg/ 24 hr to 1.2 mg/24 hr did not result in significant reductions in mean trap catch ofD. brevicomis. In contrast, very low release rates of ipsdienol (0.02–0.4 mg/24 hr) significantly reduced trap catch compared to controls. The combination of verbenone and ipsdienol, released at rates above 0.09 and 0.02 mg/24 hr, respectively, resulted in significantly lower trap catches ofD. brevicomis in attractant-baited traps. Results of an experiment testing a factorial combination of different release rates of verbenone and attractants suggest that response is not ratio-specific. The response curve ofD. brevicomis to the levels of verbenone was similar across all levels of attractants, while the response to equivalent ratios of attractants to verbenone was not similar, suggesting that the behavior of the beetles is primarily influenced by the absolute release rate of verbenone.
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    Aggregation pheromone of Australian SAP beetle,Carpophilus davidsoni (Coleoptera: Nitidulidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 3207-3219 
    Details
    ISSN: 1573-1561
    Keywords: Aggregation pheromone ; triene ; tetraene ; hydrocarbon ; Coleoptera ; Nitidulidae ; Carpophilus davidsoni ; Australian sap beetle ; trapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A male-produced aggregation pheromone was identified for the Australian sap beetle,Carpophilus davidsoni Dobson (Coleoptera: Nitidulidae), by bioassay-guided fractionation of volatiles collected from feeding beetles. The most abundant components were: (2E,4E,6E)-5-ethyl-3-methyl-2,4,6-nonatriene, (3E,5E,7E)-6-ethyl-4-methyl-3,5,7-decatriene, (2E,4E,6E,8E)-3,5,7-trimethyl-2,4,6,8-undecatetraene, and (2E,4E,6E,8E)-7-ethyl-3,5-dimethyl-2,4,6,8-undecatetraene. The relative abundance of these components in collections from individual males feeding on artificial diet was 100:7:9:31, respectively. Pheromone production began within several days after males were placed onto diet medium and continued for at least 20 weeks. Peak production was 〉3 µg total pheromone per male per day. Males in groups of 50–60 emitted less pheromone (the peak level was 0.09 µg per beetle per day), and the emissions from groups contained relatively little tetraene (proportions of the components listed above were 100:7:2:7, respectively). Three additional trienes and one additional tetraene were identified in minor amounts; the entire eight-component male-specific blend is qualitatively identical and quantitatively similar to that of the North American sibling species,C. freemani Dobson. A synthetic blend of the four major components on rubber septa, prepared to emit in the same proportions as from individual males, was highly attractive in the field when synergized with fermenting whole-wheat bread dough. Cross-attraction was observed in the field involving the pheromones ofC. davidsoni, C. hemipterus (L.), andC. mutilatus Erichson. Potential uses of the pheromones in pest management are discussed.
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    Long-chain free fatty acids: Semiochemicals for host location by western corn rootworm larvae (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 3335-3344 
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    ISSN: 1573-1561
    Keywords: Diabrotica virgifera virgifera ; fatty acids ; linoleic acid ; oleic acid ; stearic acid ; semiochemical ; attractants ; western corn rootworm ; host location ; Coleoptera ; Chrysomelidae ; Zea mays ; kairomone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A bioassay-driven sequential fractionation scheme was used to isolate fractions of a crude dichloromethane maize seedling extract behaviorally active to larvae of the western corn rootworm,Diabrotica virgifera virgifera LeConte. (Z,Z)-9,12-Octadecadienoic (linoleic) acid, (Z)-9-octadecenoic (oleic) acid, and octadecanoic (stearic) acid were identified from a purified fraction of maize extract that was attractive to western corn rootworm larvae in choice tests with equal levels of carbon dioxide on both sides of the choice. When synthetic linoleic, oleic, and stearic acids were tested together in the amounts and proportions found in the attractive fraction (1000, 800, and 300 ng of linoleic, oleic, and stearic acids, respectively), significantly more western corn rootworm larvae were found on the side with synthetic free fatty acids plus carbon dioxide than on the side with carbon dioxide alone. Results of the choice-test bioassays were not significantly different when the synthetic blend of free fatty acids was substituted for the purified maize fraction. Neither the purified extract nor the synthetic blend was behaviorally active in preliminary single-choice experiments without carbon dioxide. Linoleic, oleic, and stearic acids were also tested individually in the choice test bioassay with carbon dioxide on both sides of the choice to determine a dose-response curve. Linoleic and oleic acid each had one dose that was significantly attractive in conjunction with carbon dioxide on both sides of the choice, but stearic acid was not active in the doses tested.
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    Production of cardenolides versus sequestration of pyrrolizidine alkaloids in larvae ofOreina species (Coleoptera, Chrysomelidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 555-568 
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    ISSN: 1573-1561
    Keywords: Oreina spp. ; Coleoptera ; Chrysomelidae ; larval defense ; cardenolides ; pyrrolizidine alkaloids ; sequestration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Adult leaf beetles of the genusOreina are known to be defended either by autogenously produced cardenolides or by pyrrolizidine alkaloids (PAs) sequestered from the food plant, or both. In this paper we analyze larvae of differentOreina species and show that the larvae contain the same defensive toxins as the adults in quantities similar to those released in the adults' secretion. Both classes of toxins are found in the body and hemolymph of the larvae, despite their different origins and later distribution in the adults. Larvae of sequestering species differed in their PA patterns, even though they fed on the same food plants. The concentration in first-instar larvae of a PA-sequestering species was similar to that in fourth-instar larvae. In all stages examined, the amount of PAs per larva did not greatly exceed the estimated uptake of one day. Eggs of two oviparous species contained large concentrations of the adult's toxins, while neonates of a sequestering larviparous species had no PAs.
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    Ethyl propionate: Synergistic kairomone for african palm weevil,Rhynchophorus phoenicis L. (Coleoptera: Curculionidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 889-897 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Rhynchophorus phoenicis ; Elaeis quineensis ; kairomone ; synergism ; oil palm ; palm weevil ; palm volatiles ; host selection ; primary attraction ; aggregation pheromone ; 3-methyl-octan-4-ol ; ethyl acetate ; ethyl propionate ; isobutyl propionate ; ethyl butyrate ; ethyl isobutyrate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Small trunk pieces of a freshly felled 10-year-old oil palm,Elaeis quineensis (Jacq.), were placed in a modified Nalgene desiccator, and volatiles captured for six days on Porapak Q. Gas chromatographic (GC) analysis of Porapak-Q-trapped volatiles with both flame ionization (FID) and electroantennographic detection (EAD) using male or femaleR. phoenicis antennae revealed several EAD-active compounds. They were identified as: ethyl acetate, ethyl propionate, isobutyl propionate, ethyl butyrate, and ethyl isobutyrate. In field experiments in the La Me Research Station, Côte d'Ivoire, ethyl propionate (50 mg/24 hr) but not all esters combined (50 mg/24 hr each) significantly increased capture ofR. phoenicis in pheromone-baited (3 mg/24 hr) traps. One kilogram of 1- to 3-day-old palm tissue was significantly more effective than ethyl propionate in enhancing pheromone attraction. Superior attraction of palm tissue may be attributed to additional as yet unknown semiochemicals. Alternatively, release rates and/or ratios of synthetic volatiles differed from those of palm tissue at peak attraction.
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    Effects of two sesquiterpene lactones isolated fromArtemisia annua on physiology ofLemna minor (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 969-978 
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    ISSN: 1573-1561
    Keywords: Artemisinin ; arteannuic acid ; photosynthesis ; respiration ; chlorophyll ; Lemna minor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The effects of artemisinin and arteannuic acid extracted fromArtemisia annua on the physiology ofLemna minor were evaluated. Changes in frond production, growth, dry weight, and chlorophyll content ofL. minor were determined. Photosynthesis and respiration were evaluated with a differential respirometer. Artemisinin (5 µM) inhibitedL. minor frond production and dry weight 82 and 83%, relative to methanol controls. Chlorophyll content was reduced 44% by artemisinin (2.5 µM). Arteannuic acid (10 µM) was less active, inhibiting frond production 61% and reducing chlorophyll content 66% at 5 µM. Artemisinin (1 µM) reducedL. minor photosynthesis 30% and 2.5 µM reduced respiration 39%. Arteannuic acid had no significant effect on photosynthesis or respiration at the levels tested.
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    Behavioral and electrophysiological response of cabbage seed weevils (Ceutorhynchus assimilis) to conspecific odor (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 979-989 
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    ISSN: 1573-1561
    Keywords: Ceutorhynchus assimilis ; Coleoptera ; Curculionidae ; olfactometer ; sex pheromone ; aggregation pheromone ; electroantennogram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The responses ofCeutorhynchus assimilis Payk. (Coleoptera, Curculionidae) to the odor of overwintered and new generation weevils were studied using an olfactometer, choice tests in a laboratory cage, field tests using sticky traps baited with live weevils, and by electroantennograms (EAG's). Unmated male weevils and, to a lesser extent, female weevils of the overwintered generation were attracted to the odor of live unmated over-wintered female weevils. New generation weevils exhibited no behavioral response to conspecific odor. Male and female weevils of the overwintered generation exhibited positive EAGs to hexane extracts of overwintered female weevils, whereas EAGs of new-generation weevils of either sex were unresponsive to these extracts. This suggests that the unmated female weevils from the overwintered generation produce a volatile chemical or chemicals that attracts unmated male and female weevils. The new generation of female weevils does not produce this attractive chemical before overwintering, and male and female weevils of this generation can not detect the chemical(s) via their antennal chemoreceptors until they have undergone their overwintering period.
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    Repellent, toxic, and food protectant effects of pithraj,Aphanamixis polystachya extracts against pulse beetle,Callosobruchus chinensis in storage (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 899-908 
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    ISSN: 1573-1561
    Keywords: Aphanamixis polystachya ; pithraj ; repellent ; contact toxicity ; food protectant ; Callosobruchus chinensis ; Coleoptera ; Bruchidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Ground leaves, bark, seeds, and four seed extracts of pithraj,Aphanamixis polystachya (family Meliaceae), a locally grown plant in Bangladesh, were evaluated for their repellency, contact toxicity, and food protectant efficacy against adult pulse beetle (Callosobruchus chinensis L.). The seed extracts showed poor repellent effects, but high contact toxicity to adults at 72 hr after application. The ground leaves, bark, and seeds provided good protection for mung beans against pulse beetles, and the seed powder greatly reduced the F1 progeny and seed damage rates.
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    Leaf surface extracts ofSolanum berthaultii hawkes deter colorado potato beetle feeding (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 991-1007 
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    ISSN: 1573-1561
    Keywords: Leptinotarsa decemlineata ; Colorado potato beetle ; Coleoptera ; Chrysomelidae ; Solanum berthaultii ; glandular trichomes ; feeding deterrents ; host preference ; plant resistance to insects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Leaf rinses ofS. berthaultii PI 473334 with methylene chloride were deterrent to feeding by the Colorado potato beetle when applied toS. tuberosum tuber and leaf disks. When the leaf rinse was separated into its nonvolatile and volatile fractions and applied to tuber disks, the nonvolatile fraction was highly deterrent, while the volatile fraction reduced consumption, but not significantly compared to the controls. A hexane leaf rinse was not deterrent to feeding, while an acetone rinse was approximately twofold more deterrent than the methylene chloride rinse when applied to leaf disks. Three cycles of bioassay-guided, reversed-phase open-column fractionation of an acetone leaf rinse yielded a relatively polar fraction with low deterrent activity, and two nonpolar fractions exhibiting higher specific activity. Reversed-phase preparative HPLC of these fractions yielded seven active fractions among the 10 assayed. Subsequent analytical HPLC indicated that two fractions each contained a single UV-absorbing compound, while another represented a mixture of at least four compounds. The remaining fractions were composed of complex mixtures of possibly ionic or polymeric compounds that were poorly resolved by HPLC.
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    Composition of larval secretion ofChrysomela lapponica (Coleoptera, Chrysomelidae) and its dependence on host plant (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1075-1093 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Chrysomelidae ; Chrysomela lapponica ; larval secretion ; defense
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The defensive secretion ofChrysomela lapponica larvae, which is produced by nine pairs of exocrine dorsal glands, has been chemically analyzed. TheC. lapponica larvae were kept in the laboratory on leaves of either birch (Betula pendula), alder (Alnus glutinosa), or willow (Salix fragilis). Larvae developed normally on birch and willow, whereas those on alder died within a few days. GC-MS analyses of the secretion of larvae on birch and willow revealed that the composition of this secretion differs distinctly from the known ones of several otherChrysomela species feeding exclusively on Salicaceae. In the exocrine secretion of larvae on birch, 69 compounds were identified, which included the main components isobutyric acid, 2-methylbutyric acid, and esters of the two. Several of the esters have not been reported previously from nature. The alcoholic components of the esters may be hydrolysis products ofBetula glycosides. Most components of the secretion of larvae feeding on birch were also found in the secretion of larvae feeding on willow. In addition, major amounts of benzoic acid and salicylalcohol were present in the secretion of the larvae feeding on willow.C. lapponica obviously acquires salicylalcohol by hydrolysis of salicin from willow leaves. However, in contrast to otherChrysomela species,C. lapponica larvae oxidize only traces of salicylalcohol to salicylaldehyde. The repellent activity of single authentic compounds of the secretion of larvae feeding on birch and willow, respectively, was tested in laboratory bioassays with ants (Myrmica sabuleti). Biosynthetic pathways to some identified compounds are suggested and discussed under evolutionary and functional aspects.
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    A new bioassay for testing plant extracts and pure compounds using red flour beetleTribolium castaneum Herbst (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1161-1177 
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    ISSN: 1573-1561
    Keywords: Bioassay ; red flour beetle ; Tribolium castaneum ; Coleoptera ; Tenebrionidae ; ECI ; Minthostachis mollis ; Melaleuca quinquenervia ; Sapindus saponaria ; α-pinene ; β-pinene ; eugenol ; kaurenic acid ; sparteine ; phagodepression ; phagostimulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We designed a new bioassay to test plant extract activity against stored product pests. Plant compounds were added to feed disks composed of wheat flour and yeast and fed to the red flour bettle (Tribolium castaneum). By measuring insect mass, disk mass, and insect mortality over time it was possible to calculate a phagodepression index, an antifeedant index, the amount of treatment chemical ingested by the beetles, the mortality rate, and the efficiency of conversion of ingested food. The assay was performed for 60 hr to allow for possible habituation effects and to discriminate between phagodeterrency and physiological stress caused by treatments. α- and β-Pinene, eugenol, kaurenic acid, sparteine, essential oils ofMinthostachis mollis andMelaleuca quinquenervia, and extracts ofSapindus saponaria were tested. Using this assay we detected the presence of both phagodepressant and phagostimulant compounds inS. saponaria extracts, and we quantified the pronounced effects of sparteine onT. castaneum.
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    The scarab beetleAnomala albopilosa sakishimana utilizes the same sex pheromone blend as a closely related and geographically isolated species,Anomala cuprea (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1667-1676 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scarabaeidae ; (R,Z)-5-(−)-oct-1-enyl)oxacyclopentan-2-one ; (R,Z)-5-(−)-(dec-1-enyl)oxacyclopentan-2-one ; (R,E)-5-(−)-(oct-1-enyl)oxacyclopentan-2-one ; Anomala albopilosa sakishimana ; Anomala octiescostata ; Anomala cuprea ; pheromone release ; GC-EAD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Two components were identified in the sex pheromone system of the green chafter,Anomala albopilosa sakishimana Nomura: (R,Z)-5-(−)-(oct-1-enyl)oxacyclopentan-2-one (buibuilactone) and (R,Z)-5-(−)-(dec-1-enyl)oxyacyclopentan-2-one (japonilure), which have been previously identified as sex pheromone constituents ofA. cuprea andA. octiescostata. A female-specific minor component, (R,E)-5-(−)-(oct-1-enyl)oxacyclopentan-2-one, did not seem to be involved in pheromonal communication because it was not EAD active, but its role remained unclear. A synthetic blend of the two components captured significantly more beetles than any other treatments. Nevertheless, the fact that both the synthetic sex pheromone and field-captured female beetles were weak lures convinced us that the sex pheromone system may be only part of a complex communication system, probably involving plant volatiles. Although the sex pheromone was released during both the scotophase and photophase, there was an increase of 60% in the photophase.
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    Kairomone from dandelion,Taraxacum officinale, attractant for scarab beetleAnomala octiescostata (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1697-1704 
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    ISSN: 1573-1561
    Keywords: cis-3-Hexenyl acetate ; benzaldehyde ; phenylacetaldehyde ; benzyl alcohol ; phenethyl alcohol ; phenylacetonitrile ; benzyl benzoate ; anethol ; geraniol ; phenethyl propionate ; kairomone ; sex pheromone ; dandelion ; Taraxacum officionale ; Coleoptera ; Scarabidae ; Anomala oritescostata ; scarab beetle
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The attraction of the scarab beetleAnomala octiescostata to dandelion,Taraxacum officinale, was demonstrated to be chemically mediated by a mixture ofcis-3-hexenyl acetate, benzaldehyde, phenylacetaldehyde, benzyl alcohol, phenethyl alcohol, phenylacetonitrile, and benzyl benzoate, in the ratio 4:8:14:3:5:19:11. Combination of the synthetic kairomone and sex pheromone (buibuilactone + japonilure, 8:2), significantly increased the total catches ofA. octiescostata. Catches of male (but not female) beetles were significantly higher with the kairomone-pheromone blend than with kairomone alone. The synergistic effect of the kairomone from dandelion on the attractiveness did not significantly differ from that of a food-type lure, anethol, geraniol, and phenethyl propionate (9:0.5:0.5). The latter combined with the synthetic sex pheromone resulted in better attraction of female (but not male)A. octiescostata than the sex pheromone alone.
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    URL: http://dx.doi.org/10.1007/BF02059891
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    Sex pheromone of oriental beetle,Exomala orientalis: Identification and field evaluation (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1705-1718 
    Details
    ISSN: 1573-1561
    Keywords: Exomala orientalis ; Blitopertha orientalis ; Phyllopertha orientalis ; Coleoptera ; Scarabaeidae ; Oriental beetle ; 7-tetradecen-2-one ; 6-tetradecen-2-one ; 5-tetradecen-2-one ; 2-(E)-nonenol ; japonilure ; GC-EAD ; GC-BB
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A gas chromatograph coupled with a behavioral bioassay was used to identify two sex pheromone components, 7-(Z)- and 7-(E)-tetradecen-2-one of the Oriental beetle (OB),Exomala orientalis. Field experiments showed that the blend of the two isomers (Z:E, 7:1) was not significantly more attractive than theZ component alone. The best performance of traps baited with the synthetic sex pheromone was achieved when they were set with the pheromone device at 30 cm above the ground. Catches in traps baited with 1 and 10 mg were not significantly different, but they were higher (2.9-fold) than captures in traps loaded with 0.1 mg of the pheromone. Further investigations by GC-EAD revealed the presence of a possible minor component, but the small amount of material prevented its identification. 2-(E)-Nonenol, with the same retention time as the natural product, did not affect the attractancy of the synthetic sex pheromone. GC-EAD screening of previously identified sex pheromones of scarab beetles showed that male antennae of the Oriental beetle responded to japonilure, but it showed neither synergism nor inhibition to the OB sex pheromone.
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    URL: http://dx.doi.org/10.1007/BF02059892
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    Repellent properties of the host compound 4-allylanisole to the southern pine beetle (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1595-1615 
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    ISSN: 1573-1561
    Keywords: Coleoptera ; Scolytidae ; Dendroctonus frontalis ; Pinus ; host compound ; 4-allylanisole ; repellent ; semiochemical ; verbenone ; inhibitor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The phenylpropanoid 4-allylanisole is a compound produced by loblolly pines (Pinus taeda L.), an abundant species in southern pine forests and a preferred host of southern pine beetle (Dendroctonus frontalis Zimmermann). Repellency of individual beetles was demonstrated in laboratory behavioral assays ofD. frontalis and other scolytids. Inhibition was demonstrated in natural populations ofD. frontalis using baited traps. In both tests, response to the inhibitory pheromone verbenone was used for comparison. In the laboratory, a higher proportion of newly emerged and reemergedD. frontalis responded negatively to 4-allylanisole than to verbenone. However, fewer reemergent than newly emerged individuals responded to either compound. In all field trials, the response ofD. frontalis to its attractant pheromone in funnel traps was significantly reduced by simultaneous release of 4-allylanisole. In most trials total reduction did not differ from verbenone; however, unlike verbenone, 4-allylanisole reduced male and female catches proportionally. Both compounds together did not significantly further reduce trap catch. The response of a major predator,Thanasimus dubius (F.), to the attractant pheromone ofD. frontalis, did not differ with the simultaneous release of either verbenone or 4-allylanisole. The results of preliminary field applications are presented and discussed.
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    URL: http://dx.doi.org/10.1007/BF02059883
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    Influence of aggregation inhibitors (verbenone and ipsidenol) on landing and attack behavior ofDendroctonus brevicomis (Coleoptera: Scolytidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 1617-1629 
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    ISSN: 1573-1561
    Keywords: Dendroctonus brevicomis ; Coleoptera ; Scolytidae ; Pinus ponderosa ; aggregation ; verbenone ; ipsdienol ; pheromone ; inhibitors ; tree protection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The influence of the aggregation inhibitors verbenone and ipsdienol on the response of western pine beetle,Dendroctonus brevicomis, to attractive host trees was investigated. Paired ponderosa pine trees (Pinus ponderosa) were baited with aggregation semiochemicals to stimulate mass attack. One tree in each pair received an inhibitor treatment consisting of five sets of two verbenone and two ipsdienol dispensers spaced 1 m apart vertically along the tree bole. Beetle landing was monitored with sticky traps on the tree bole, and attack density was assessed from bark samples removed four or seven days after baiting. The inhibitor treatment resulted in a significant reduction of both the numbers of beetles landing on trees and the density of attacking beetles compared to control trees (without inhibitors). The ratios of beetle landing density to attacking density were not different between inhibitor-treated and control trees, nor were the vertical distributions of beetles landing or attacking, suggesting that beetle behavior was primarily influenced at a longer range, prior to landing on the tree. Although the application of verbenone and ipsdienol did not preventD. brevicomis from attacking baited trees, our results suggest that when applied to unattacked (and unbaited) trees, their effectiveness at reducing the attack pressure might allow trees having a certain amount of resistance to survive attack by pioneer beetles.
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    Isolation of 8-hydroxygeraniol-8-O-β-d-glucoside, a probable intermediate in biosynthesis of iridoid monoterpenes, from defensive secretions ofPlagiodera versicolora andGastrophysa viridula (Coleoptera: Chrysomelidae) (1994)
    Springer
    Journal of chemical ecology 20 (1994), S. 2089-2097 
    Details
    ISSN: 1573-1561
    Keywords: Coleoptera ; Chrysomelidae ; defensive secretion ; Plagiodera versicolora ; Gastrophysa viridula ; β-glucosidase ; oxidase ; 8-hydroxygeraniol ; 8-hydroxygeraniol-8-O-β-d-glucoside
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 8-Hydroxygeraniol and its 8-O-β-d-glucoside have been found as trace components in the defensive secretions ofPlagiodera versicolora andGastrophysa viridula larvae. This discovery supports the hypothesis that the evolution of the utilization of plant precursors by some chrysomelid species was favored by the plesiomorphic occurrence of aβ-glucosidase and an oxidase in the defensive secretion of iridoid-producing species.
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    URL: http://dx.doi.org/10.1007/BF02066245
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    Photosynthetic electron transport and anaerobic metabolism in purple non-sulfur phototrophic bacteria (1994)
    Springer
    Antonie van Leeuwenhoek 66 (1994), S. 151-164 
    Details
    ISSN: 1572-9699
    Keywords: purple non-sulfur bacteria ; Rhodobacter ; photosynthesis ; CO2 fixation ; anaerobic respiration ; gene expression
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Purple non-sulfur phototrophic bacteria, exemplifed byRhodobacter capsulatus andRhodobacter sphaeroides, exhibit a remarkable versatility in their anaerobic metabolism. In these bacteria the photosynthetic apparatus, enzymes involved in CO2 fixation and pathways of anaerobic respiration are all induced upon a reduction in oxygen tension. Recently, there have been significant advances in the understanding of molecular properties of the photosynthetic apparatus and the control of the expression of genes involved in photosynthesis and CO2 fixation. In addition, anaerobic respiratory pathways have been characterised and their interaction with photosynthetic electron transport has been described. This review will survey these advances and will discuss the ways in which photosynthetic electron transport and oxidation-reduction processes are integrated during photoautotrophic and photoheterotrophic growth.
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    URL: http://dx.doi.org/10.1007/BF00871637
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    Protein structure, electron transfer and evolution of prokaryotic photosynthetic reaction centers (1994)
    Springer
    Antonie van Leeuwenhoek 65 (1994), S. 311-329 
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    ISSN: 1572-9699
    Keywords: photosynthesis ; chlorophyll ; bacteriochlorophyll ; reaction center ; electron transfer ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Photosynthetic reaction centers from a variety of organisms have been isolated and characterized. The groups of prokaryotic photosynthetic organisms include the purple bacteria, the filamentous green bacteria, the green sulfur bacteria and the heliobacteria as anoxygenic representatives as well as the cyanobacteria and prochlorophytes as oxygenic representatives. This review focuses on structural and functional comparisons of the various groups of photosynthetic reaction centers and considers possible evolutionary scenarios to explain the diversity of existing photosynthetic organisms.
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    URL: http://dx.doi.org/10.1007/BF00872216
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    Genetic variation for resistance to low-temperature photoinhibition of photosynthesis in maize (Zea mays L.) (1994)
    Springer
    Euphytica 80 (1994), S. 85-93 
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    ISSN: 1573-5060
    Keywords: maize ; Zea mays ; photoinhibition ; photosynthesis ; low-temperature adaptation ; breeding
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Sixty-seven inbred lines of maize were evaluated for resistance to low-temperature photoinhibition of photosynthesis, using a pulse-modulated chlorophyll fluorescence technique. The evaluation procedure was based on leaf discs, which were exposed to a high irradiance (1000 µmol/m2/s) at 7°C. The efficiency of open PSII reaction centres as a reflection of overall photosynthesis was measured before and after a photoinhibition-inducing treatment. Exposure of leaf discs to photoinhibitory condition for 2, 4, and 8 hours resulted in an efficiency reduction of 30, 53 and 83%, respectively. Testing of inbred lines showed large differences for photoinhibition susceptibility. The difference in photosynthetic efficiency between the most extreme lines after a treatment of eight hours was 39%. Resistance to photoinhibition was shown to be relevant under cool field conditions. It proved to be a trait strongly amenable to selection.
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    Optimal acclimation of the C3 photosynthetic system under enhanced CO2 (1994)
    Springer
    Photosynthesis research 39 (1994), S. 401-412 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; elevated CO2 ; source-sink interactions ; Rubisco
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A range of studies of C3 plants have shown that there is a change in both the carbon flux and the pattern of nitrogen allocation when plants are grown under enhanced CO2. This paper examines evidence that allocation of nitrogen both to and within the photosynthetic system is optimised with respect to the carbon flux. A model is developed which predicts the optimal relative allocation of nitrogen to key enzymes of the photosynthetic system as a function of CO2 concentration. It is shown that evidence from flux control analysis is broadly consistent with this model, although at high nitrogen and under certain conditions at low nitrogen experimental data are not consistent with the model. Acclimation to enhanced CO2 is also assessed in terms of resource allocation between photosynthate sources and sinks. A means of assessing the optimisation of this source-sink allocation is proposed, and several studies are examined within this framework. It is concluded that C3 plants probably possess the genetic feedback mechanisms required to efficiently ‘smooth out” any imbalance within the photosynthetic system caused by a rise in atmospheric CO2.
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    URL: http://dx.doi.org/10.1007/BF00014594
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    Biochemical and molecular basis for impairment of photosynthetic potential (1994)
    Springer
    Photosynthesis research 39 (1994), S. 453-462 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; Rubisco ; ozone ; oxidative stress ; rbcS mRNA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ozone induces reductions in net photosynthesis in a large number of plant species. A primary mechanism by which photosynthesis is reduced is through impact on carbon dioxide fixation. Ozone induces loss in Rubisco activity associated with loss in concentration of the protein. Evidence is presented that ozone may induce oxidative modification of Rubisco leading to subsequent proteolysis. In addition, plants exposed to ozone sustain reduction in rbcS, the mRNA for the small subunit of Rubisco. This loss in rbcS mRNA may lead to a reduced potential for synthesis of the protein. The regulation of O3-induced loss of Rubisco, and implications of the decline in this protein in relation to accelerated senescence are discussed.
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    URL: http://dx.doi.org/10.1007/BF00014598
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    Reminiscence about‘Chloropseudomonas ethylicum’ and the FMO-protein (1994)
    Springer
    Photosynthesis research 41 (1994), S. 3-5 
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    ISSN: 1573-5079
    Keywords: bacteriochlorophylla-protein ; green sulfur bacteria ; Prosthecochloris aestuarii ; Chlorobium limicola ; photosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In 1961 the green sulfur bacterium-containing mixed culture known as‘Chloropseudomonas ethylicum’ was brought to Brookhaven National Laboratory (USA) from Moscow State University (USSR). The water-soluble bacteriochlorophylla-protein (FMO-protein) was extracted, purified and characterized by absorption and circular dichroism spectroscopy, by X-ray crystallography and by primary structure determination.
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    URL: http://dx.doi.org/10.1007/BF02184138
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    Rates of vectorial proton transport supported by cyclic electron flow during oxygen reduction by illuminated intact chloroplasts (1994)
    Springer
    Photosynthesis research 41 (1994), S. 419-428 
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    ISSN: 1573-5079
    Keywords: 9-aminoacridine fluorescence ; cyclic electron transport ; Mehler reaction ; photosynthesis ; photosystems ; transthylakoid proton gradient
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The light-dependent quenching of 9-aminoacridine fluorescence was used to monitor the state of the transthylakoid proton gradient in illuminated intact chloroplasts in the presence or absence of external electron acceptors. The absence of appreciable light-dependent fluorescence quenching under anaerobic conditions indicated inhibition of coupled electron transport in the absence of external electron acceptors. Oxygen relieved this inhibition. However, when DCMU inhibited excessive reduction of the plastoquinone pool in the absence of oxygen, coupled cyclic electron transport supported the formation of a transthylakoid proton gradient even under anaerobiosis. This proton gradient collapsed in the presence of oxygen. Under aerobic conditions, and when KCN inhibited ribulose bisphosphate carboxylase and ascorbate peroxidase, fluorescence quenching indicated the formation of a transthylakoid proton gradient which was larger with oxygen in the Mehler reaction as electron acceptor than with methylviologen at similar rates of linear electron transport. Apparently, cyclic electron transport occured simultaneously with linear electron transport, when oxygen was available as electron acceptor, but not when methylviologen accepted electrons from Photosystem I. The ratio of cyclic to linear electron transport could be increased by low concentrations of DCMU. This shows that even under aerobic conditions cyclic electron transport is limited in isolated intact chloroplasts by excessive reduction of electron carriers. In fact, P700 in the reaction center of Photosystem I remained reduced in illuminated isolated chloroplasts under conditions which resulted in extensive oxidation of P700 in leaves. This shows that regulation of Photosystem II activity is less effective in isolated chloroplasts than in leaves. Assuming that a Q-cycle supports a H+/e ratio of 3 during slow linear electron transport, vectorial proton transport coupled to Photosystem I-dependent cyclic electron flow could be calculated. The highest calculated rate of Photosystem I-dependent proton transport, which was not yet light-saturated, was 330 μmol protons (mg chlorophyll h)−1 in intact chloroplasts. If H+/e is not three but two proton transfer is not 330 but 220 μmol (mg Chl H)−1. Differences in the regulation of cyclic electron transport in isolated chloroplasts and in leaves are discussed.
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    Pigment orientation changes accompanying the light state transition in Synechococcus sp. PCC 6301 (1994)
    Springer
    Photosynthesis research 40 (1994), S. 35-44 
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    ISSN: 1573-5079
    Keywords: allophycocyanin ; chlorophyll a ; linear dichroism ; phycobilisome ; photosynthesis ; state transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Low temperature (77 K) linear dichroism spectroscopy was used to characterize pigment orientation changes accompanying the light state transition in the cyanobacterium, Synechococcus sp. PCC 6301 and those accompanying chromatic acclimation in Porphyridium cruentum in samples stabilized by glutaraldehyde fixation. In light state 2 compared to light state 1 intact cells of Synechococcus showed an increased alignment of allophycocyanin parallel to the cells' long axis whereas the phycobilisomethylakoid membrane fragments exhibited an increased allophycocyanin alignment parallel to the membrane plane. The phycobilisome-thylakoid membrane fragments showed less alignment of a short wave-length chlorophyll a (Chl a) Qy transition dipole parallel to the membrane plane in state 2 relative to state 1. To aid identification of the observed Chl a orientation changes in Synechococcus, linear dichroism spectra were obtained from phycobilisome-thylakoid membrane fragments isolated from red light-grown (increased number of PS II centres) and green light-grown (increased number of PS I centres) cells of the red alga Porphyridium cruentum. An increased contribution of short wavelength Chl a Qy transition dipoles parallel to the long axis of the membrane plane was directly correlated with increased levels of PS II centres in red light-grown P. cruentum. Our results indicate that the transition to state 2 in cyanobacteria is accompanied by an increase in the orientation of allophycocyanin and a decrease in the orientation of Chl a associated with PS II with respect to the thylakoid membrane plane.
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    Photoinhibition of photosynthesis in chilled potato leaves is not correlated with a loss of Photosystem-II activity (1994)
    Springer
    Photosynthesis research 40 (1994), S. 75-92 
    Details
    ISSN: 1573-5079
    Keywords: chilling temperature ; oxygen toxicity ; photoinhibition ; photosynthesis ; photosystems ; superoxide dismutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When 23 °C-grown potato leaves (Solanum tuberosum L.) were irradiated at 23 °C with a strong white light, photosynthetic electron transport and Photosystem-II (PS II) activity were inhibited in parallel. When the light treatment was given at a low temperature of 3 °C, the photoinhibition of photosynthesis was considerably enhanced, as expected. Surprisingly, no such stimulation of photoinhibition was observed with respect to the PS II function. A detailed functional analysis of the photosynthetic apparatus, using in-vivo fluorescence, absorbance, oxygen and photoacoustic measurements, and artificial electron donors/acceptors, showed a pronounced alteration of PS I activity during light stress at low temperature. More precisely, it was observed that both the pool of photooxidizeable reaction center pigment (P700) of PS I and the efficiency of PS I to oxidize P700 were dramatically reduced. Loss of P700 activity was shown to be essentially dependent on atmospheric O2 and to require a continued flow of electrons from PS II, suggesting the involvement of the superoxide anion radical which is produced by the interaction of O2 and the photosynthetic electron-transfer chain through the Mehler reaction. Mass spectrometric measurements of O2 exchange by potato leaves under strong illumination did not reveal, however, any stimulation of the Mehler reaction at low temperature, thus leading to the conclusion that O2 toxicity mainly resulted from a chilling-induced inhibition of the scavenging system for O2-radicals. Support for this interpretation was provided by the light response of potato leaves infiltrated with an inhibitor (diethyldithiocarbamate) of the chloroplastic Cu-Zn superoxide dismutase. It was indeed possible to simulate the differential inhibition of the PS II photochemical activity and the linear electron transport observed during light stress at low temperature by illuminating at 23 °C diethyldithiocarbamate-poisoned leaves. The experimental data presented here suggests that (i) the previously reported resistance of PS I to photoinhibition damage in-vivo is not an intrinsic property of PS I but results from efficient protective systems against O2 toxicity, (ii) PS I is photoinhibited in chilled potato leaf due to the inactivation of this PS I defence system and (iii) PS I is more sensitive to superoxide anion radicals than PS II.
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    Sixty years in algal physiology and photosynthesis (1994)
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    Photosynthesis research 40 (1994), S. 207-221 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; unicellular algae ; ion effects ; manganese ; blue light ; synchronized growth ; algal mass cultures
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This personal perspective records research experiences in chemistry and biology at four German universities, two before and two after World War II. The research themes came from cytophysiology of green unicellular algae, in particular their photosynthesis. The function of inorganic ions in photosynthesis and dark respiration was investigated at different degrees of specific mineral stress (deficiencies), and the kinetics of recovery followed after the addition of the missing element. Two types of recovery of photosynthesis were observed: indirect restitution via growth processes and immediate normalisation. From the latter case (K+, phosphate, Mn++) the effect of manganese was emphasized as its role in photosynthetic O2 evolution became established during our research. Other themes of our group, with some bearing on photosynthesis were: synchronization of cell growth by light-dark change and effects of blue (vs. red) light on the composition of green cells. Some experiences in connection with algal mass cultures are included. Discussion of several editorial projects shows how photosynthesis, as an orginally separated field of plant biochemistry and biophysics, became included into general cell physiology and even ecophysiology of green plants. The paper contains an appreciation of the authors' main mentor Kurt Noack (1888–1963) and of Ernst Georg Pringsheim (1881–1970), founder of experimental phycology.
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    Gene nomenclature recommendations for green photosynthetic bacteria and heliobacteria (1994)
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    Photosynthesis research 41 (1994), S. 27-28 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; reaction center ; green bacteria ; heliobacteria ; gene ; chlorosome ; cytochrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Recommendations are given for naming of genes coding for reaction center, antenna and electron transport proteins in green photosynthetic bacteria and heliobacteria
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    URL: http://dx.doi.org/10.1007/BF02184142
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    Redox effects on the bacteriochlorophyll α-containing Fenna-Matthews-Olson protein fromChlorobium tepidum (1994)
    Springer
    Photosynthesis research 41 (1994), S. 89-96 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; Chlorobium tepidum ; antenna ; bacteriochlorophylla protein ; energy transfer ; chlorosome ; green bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The BChla-containing Fenna-Matthews-Olson (FMO) protein from the green sulfur bacteriumChlorobium tepidum was purified and characterized. Fluorescence spectra indicate that efficient excited state quenching occurs at neutral or oxidizing redox potentials. The major fluorescence lifetime at room temperature is approximately 60 ps in samples that are in neutral or oxidizing conditions, and approximately 2 ns in samples where the strong reductant sodium dithionite has been added. A similar change is observed in pump-probe picosecond absorbance difference experiments, where the long life time component increases after dithionite addition. A 16 Gauss wide EPR signal with g factor =2.005 is observed in samples without dithionite. This signal largely disappears upon addition of dithionite. Dithionite induces large reversibile changes in the 77 K absorbance spectra of the purified FMO protein and in whole cells. These results indicate that the FMO protein contains redox active groups, which may be involved in the regulation of energy transfer. Room temperature circular dichroism and low temperature absorption spectra show that dithionite also induces conformational or structural changes of the FMO protein complex.
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    Responses to drought and flooding in tropical forage grasses (1994)
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    Plant and soil 164 (1994), S. 97-105 
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    ISSN: 1573-5036
    Keywords: alcohol dehydrogenase ; drought ; flooding ; photosynthesis ; tropical grasses ; water potential
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Long dry seasons or permanent flooding, typical of tropical savannas, severely limit the growth of pasture plants. This study compares the responses of water relations, carbon assimilation and alcohol dehydrogenase (ADH) activity to drought and flooding in four perennial C4 grasses: the tufted or caespitose Hyparrhenia rufa and Andropogon gayanus (CIAT 621) and the stoloniferous Brachiaria mutica and Echinochloa polystachya. Plants of the four species were subjected to medium term flooding (20–25 days) and moderate drought in a greenhouse. Leaf water potential (Ψ), stomatal conductance (Gs) and photosynthesis rate (Pn) were measured throughout the experiment and ADH activity was measured in flooded and control plants. Moderate drought produced similar effects in all grasses reducing Gs which caused reduced Pn. Net photosynthesis compensation point was reached at the lowest Ψ in A. gayanus which was considered as the most drought tolerant. The responses to flooding varied across species. Andropogon gayanus and H. rufa showed early stomatal closure without concurrent decrease in Ψ and leaf turgor. This low Gs was responsible of reduced Pn and growth rate. There was a slight increase of Gs in the middle of the flooding period and both grasses recovered pre-stress Gs and Pn after drainage. ADH activity increased markedly only in A. gayanus under flooding suggesting that this grass was the most flood-sensitive. Stomatal aperture, Pn and ADH activity in B. mutica and E. polystachya were not affected by flooding. The higher flood-tolerance in these grasses might be attributed to enhanced oxygen diffusion to the roots through the hollow stolons, development of advantitious rootlets and large aerenchyma in the roots which compensate for the reduction of soil oxygen and permit the maintenance of root activity.
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    Gene action and heritability for photosynthetic activity in two wheat crosses (1994)
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    Euphytica 76 (1994), S. 235-238 
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    ISSN: 1573-5060
    Keywords: Triticum aestivum ; wheat ; photosynthesis ; gene action ; heritability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Gene action and heritability for photosynthetic activity were estimated from generation means in two wheat crosses during two stages (5 th leaf and flag leaf between 2 and 5 days after anthesis). Six generations were available for each cross: parents (P1 and P2), F1, F2 and backcrosses (BC1 and BC2). Correlations between some morphophysiological characters and photosynthetic activity of the flag leaf was also determined. The joint scaling test described by Mather & Jinks was used to determine the gene action. It showed that them; [d]; [h]; [i], [l] (mean, additivity, dominance, additive x additive interallelic interaction effects, dominance x dominance interallelic interaction effects) model fits the two crosses at both measurement times. All the model genetic components were significant for the flag leaf, however for the 5 th leaf only [h]; [i] and [l] were significant. The presence of additive and additive x additive effects suggested the possibility of selecting for this character using the flag leaf so as to obtain pure inbred lines. Dominance effects [h] were negative and dominance x dominance effects [l] were positive. Broad sense heritability values were medium to low. There were no correlations between the studied morphophysiological characters and the photosynthetic activity.
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    URL: http://dx.doi.org/10.1007/BF00022168
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    Singlet oxygen production in thylakoid membranes during photoinhibition as detected by EPR spectroscopy (1994)
    Springer
    Photosynthesis research 39 (1994), S. 191-199 
    Details
    ISSN: 1573-5079
    Keywords: photoinhibition ; photosynthesis ; protein degradation ; singlet oxygen ; TEMP (2,2,6,6-tetramethylpiperidine) ; thylakoid
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Exposure of isolated spinach thylakoids to high intensity illumination (photoinhibition) results in the well-characterized impairment of Photosystem II electron transport, followed by degradation of the D1 reaction centre protein. In the present study we demonstrate that this process is accompanied by singlet oxygen production. Singlet oxygen was detected by EPR spectroscopy, following the formation of stable nitroxide radicals from the trapping of singlet oxygen with a sterically hindered amine TEMP (2,2,6,6-tetramethylpiperidine). There was no detectable singlet oxygen production during anaerob photoinhibition or in the presence of sodium-azide. Comparing the kinetics of the loss of PS II function and D1 protein with that of singlet oxygen trapping suggests that singlet oxygen itself or its radical product initiates the degradation of D1.
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    URL: http://dx.doi.org/10.1007/BF00029386
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  • 89
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    Changes in the antenna size of Photosystem I and Photosystem II in Synechococcus sp. strain PCC 7942 grown in the presence of SANDOZ 9785 — a Photosystem II inhibitor (1994)
    Springer
    Photosynthesis research 41 (1994), S. 303-313 
    Details
    ISSN: 1573-5079
    Keywords: cyanobacteria ; excitation energy ; herbicide ; photochemical apparatus ; photosynthesis ; pyridazinone
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract SANDOZ 9785, also known as BASF 13.338, is a pyridazinone derivative that inhibits Photosystem II (PS II) activity leading to an imbalance in the rate of electron transport through the photosystems. Synechococcus sp. strain PCC 7942 cells grown in the presence of sublethal concentration of SANDOZ 9785 (SAN 9785) for 48 hours exhibited a 20% decrease in Chl a per cell. However, no changes were observed in the content of phycocyanin per cell, the size of the phycobilisomes or in the PS II:PS I ratio. From an estimate of PS II electron transport rate under varying light intensities and spectral qualities and analysis of room temperature Chl a fluorescence induction, it was deduced that growth of Synechococcus PCC 7942 in the presence of SAN 9785 leads to a redistribution of excitation energy in favour of PS II. Though the redistribution appears to be primarily caused by changes affecting the Chl a antenna of PS II, the extent of energetic coupling between phycobilisomes and PS II is also enhanced in SAN 9785 grown Synechococcus PCC 7942 cells. There was a reduction in the effective size of PS I antenna based on measurement of P700 photooxidation kinetics. These results indicate that when PS II is partially inhibited, the structure of photosynthetic apparatus alters to redistribute the excitation energy in favour of PS II so that the efficiency of utilization of light energy by the two photosystems is optimized. Our results suggest that under the conditions used, drastic structural changes are not essential for redistribution of excitation energy between the photosystems.
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    URL: http://dx.doi.org/10.1007/BF00019408
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  • 90
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    Acclimation of photosynthesis to increasing atmospheric CO2: The gas exchange perspective (1994)
    Springer
    Photosynthesis research 39 (1994), S. 351-368 
    Details
    ISSN: 1573-5079
    Keywords: CO2 enrichment ; gas exchange ; greenhouse effect ; photosynthesis ; responses to CO2
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The nature of photosynthetic acclimation to elevated CO2 is evaluated from the results of over 40 studies focusing on the effect of long-term CO2 enrichment on the short-term response of photosynthesis to intercellular CO2 (the A/Ci response). The effect of CO2 enrichment on the A/Ci response was dependent on growth conditions, with plants grown in small pots (〈 5 L) or low nutrients usually exhibiting a reduction of A at a given Ci, while plants grown without nutrient deficiency in large pots or in the field tended to exhibit either little reduction or an enhancement of A at a given Ci following a doubling or tripling of atmospheric CO2 during growth. Using theoretical interpretations of A/Ci curves to assess acclimation, it was found that when pot size or nutrient deficiency was not a factor, changes in the shape of A/Ci curves which are indicative of a reallocation of resources within the photosynthetic apparatus typically were not observed. Long-term CO2 enrichment usually had little effect or increased the value of A at all Ci. However, a minority of species grown at elevated CO2 exhibited gas exchange responses indicative of a reduced amount of Rubisco and an enhanced capacity to metabolize photosynthetic products. This type of response was considered beneficial because it enhanced both photosynthetic capacity at high CO2 and reduced resource investment in excessive Rubisco capacity. The ratio of intercellular to ambient CO2 (the Ci/Ca ratio) was used to evaluate stomatal acclimation. Except under water and humidity stress, Ci/Ca exhibited no consistent change in a variety of C3 species, indicating no stomatal acclimation. Under drought or humidity stress, Ci/Ca declined in high-CO2 grown plants, indicating stomata will become more conservative during stress episodes in future high CO2 environments.
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    URL: http://dx.doi.org/10.1007/BF00014591
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    Effects of UV-B radiation on photosynthesis and growth of terrestrial plants (1994)
    Springer
    Photosynthesis research 39 (1994), S. 463-473 
    Details
    ISSN: 1573-5079
    Keywords: global climate change ; ozone depletion ; photosynthesis ; Photosystem II ; productivity ; UV-B radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The photosynthetic apparatus of some plant species appears to be well-protected from direct damage from UV-B radiation. Leaf optical properties of these species apparently minimizes exposure of sensitive targets to UV-B radiation. However, damage by UV-B radiation to Photosystem II and Rubisco has also been reported. Secondary effects of this damage may include reductions in photosynthetic capacity, RuBP regeneration and quantum yield. Furthermore, UV-B radiation may decrease the penetration of PAR, reduce photosynthetic and accessory pigments, impair stomatal function and alter canopy morphology, and thus indirectly retard photosynthetic carbon assimilation. Subsequently, UV-B radiation may limit productivity in many plant species. In addition to variability in sensitivity to UV-B radiation, the effects of UV-B radiation are further confounded by other environmental factors such as CO2, temperature, light and water or nutrient availability. Therefore, we need a better understanding of the mechanisms of tolerance to UV-B radiation and of the interaction between UV-B and other environmental factors in order to adequately assess the probable consequences of a change in solar radiation.
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    URL: http://dx.doi.org/10.1007/BF00014599
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  • 92
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    State adaptations in the cyanobacterium Synechcoccus 6301 (PCC): Dependence on light intensity or spectral composition? (1994)
    Springer
    Photosynthesis research 40 (1994), S. 107-117 
    Details
    ISSN: 1573-5079
    Keywords: photosynthesis ; state adaptations ; shade adaptation ; cyanobacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A profile of high light to intense self-shading conditions was constructed using a white light source and cultures of the cyanobacterium Synechococcus 6301; this profile approximates to a natural self-shading gradient of decreasing light intensity and PS II/PS I excitation ratio. Samples of S.6301 were placed along this profile and allowed to state adapt. To separate the effects of light intensity and wavelength on state adaptation, samples were also placed in a shade profile produced by a white light source and neutral density filters. After adaptation, samples were fixed in their resulting state by the addition of glutaraldehyde, and fluorescence measurements were made at 35° C or –160 °C. It is concluded: 1. Under conditions of deep shade (〈5 μmol m−2s−1 PAR) and weak shade (〉200 μmol m−2s−1 PAR), cells adapt to a low PS II fluorescence state (state 2); in moderate shade (20–60 μmol m−2s−1PAR) cells adapt to a high PS II fluorescence state (state 1). We suggest these findings provide evidence for the operation of different factors on the control of state adaptations in cyanobacteria; one set operates at low light and another at high light intensities. 2. Under conditions of self-shading, there is little evidence to support the contention that state adaptations in cyanobacteria are produced by wavelength-dependent changes in the PS II/PS I excitation ratio, instead, it appaers they are produced by changes in the intensity of incident irradiation. 3. The observed fluorescence changes do not appear to involve major changes in the phycobilisome sensitisation of PS II and PS I. Instead, it appears that these changes are effected by alterations in ΦF of PS II (i.e. changes in PS II excitation density caused by alterations in the rate constants controlling spillover to PS I, photochemistry, fluorescence emission or thermal deactivation.
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    URL: http://dx.doi.org/10.1007/BF00019049
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    An enzyme and13C-NMR study of carbon metabolism in heliobacteria (1994)
    Springer
    Photosynthesis research 41 (1994), S. 75-88 
    Details
    ISSN: 1573-5079
    Keywords: photosynthesis ; carbon assimilation ; photosynthetic bacteria ; citric-acid cycle ; pyruvate synthase ; fermentation ; heliobacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Heliobacteria are a group of anoxygenic phototrophs that can grow photoheterotrophically in defined minimal media on only a limited range of organic substrates as carbon sources. In this study the mechanisms which operate to assimilate carbon and the routes employed for the biosynthesis of cellular intermediates were investigated in a newHeliobacterium strain, HY-3. This was achieved using two approaches (1) by measuring the activities of key enzymes in cell-free extracts and (2) by the use of13C nuclear magnetic resonance (NMR) spectroscopy to analyze in detail the labelling pattern of amino-acids of cells grown on [13C] pyruvate and [13C] acetate.Heliobacterium strain HY-3 was unable to grow autotrophically on CO2/H2 and neither (ATP)-citrate lyase nor ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBPcase) were detectable in cell-free extracts. The enzyme profile of pyruvate grown cells indicated the presence of a pyruvate:acceptor oxidoreductase at high specific activity which could convert pyruvate to acetyl-Coenzyme A. No pyridine nucleotide dependent pyruvate dehydrogenase complex activity was detected. Of the citric-acid cycle enzymes, malate dehydrogenase, fumarase, fumarate reductase and an NADP-specific isocitrate dehydrogenase were readily detectable but no aconitase or citrate synthase activity was found. However, the labelling pattern of glutamate in long-term 2-[13C] acetate incorporation experiments indicated that a mechanism exists for the conversion of carbon from acetyl-CoA into 2-oxoglutarate. A 2-oxoglutarate:acceptor oxidoreductase activity was present which was also assayable by isotope exchange, but no 2-oxoglutarate dehydrogenase complex activity could be detected. Heliobacteria appear to use a type of incomplete reductive carboxylic acid pathway for the conversion of pyruvate to 2-oxoglutarate but are unable to grow autotrophically using this metabolic route due to the absence of ATP-citrate lyase.
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    URL: http://dx.doi.org/10.1007/BF02184147
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    Spectroscopic evidence for the presence of an iron-sulfur center similar to Fx of Photosystem I inHeliobacillus mobilis (1994)
    Springer
    Photosynthesis research 41 (1994), S. 115-123 
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    ISSN: 1573-5079
    Keywords: photosynthesis ; bacteriochlorophyll ; electron acceptor ; iron-sulfur center ; Photosystem I ; heliobacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Treatment of membranes ofHeliobacillus mobilis with high concentrations of the chaotropic agent urea resulted in the removal of the iron-sulfur centers FA and FB from the reaction center, as indicated by EPR spectra under strongly reducing conditions. In urea-treated membranes, transient absorption measurements upon a laser flash indicated a recombination between the photo-oxidized primary donor P798+ and a reduced acceptor with a time constant of 20 ms at room temperature. Benzylviologen, vitamin K-3 and methylene blue were found to accept electrons from the reduced acceptor efficiently. A differential extinction coefficient of 225–240 mM−1 cm−1 at 798 nm was determined from experiments in the presence of methylene blue. Transient absorption difference spectra between 400 and 500 nm in the presence and absence of artificial acceptors indicated that the electron acceptor involved in the 20 ms recombination has an absorption spectrum similar to that of an iron-sulfur center. This iron-sulfur center was assigned to be analogous to FX of Photosystem I. Our results provide evidence in support of the presence of FX in heliobacteria, which was proposed on the basis of the reaction center polypeptide sequence (Liebl et al. (1993) Proc. Natl. Acad. Sci. USA 90: 7124–7128). Implications for the electron transfer pathway in the reaction center of heliobacteria are discussed.
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    URL: http://dx.doi.org/10.1007/BF02184151
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    Molecular organization of bacteriochlorophyll in chlorosomes of the green photosynthetic bacteriumChloroflexus aurantiacus: Studies of fluorescence depolarization accompanied by energy transfer processes (1994)
    Springer
    Photosynthesis research 41 (1994), S. 181-191 
    Details
    ISSN: 1573-5079
    Keywords: energy transfer ; green bacteria ; photosynthesis ; picosecond spectroscopy ; pigment system ; (Chloroflexus aurantiacus)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Examination was made of changes in fluorescence polarization plane by energy transfer in the chlorosomes of the green photosynthetic bacterium,Chloroflexus aurantiacus. Fluorescence anisotropy in the picosecond (ps) time region was analyzed using chlorosomes suspended in solution as well as those oriented in a polyacrylamide gel. When the main component of BChlc was preferentially excited, the decay of fluorescence anisotropy was found to depend on wavelength. In the chlorosome suspension, the anisotropy ratio of BChlc changed from 0.31 to 0.24 within 100 ps following excitation. In the baseplate BChla region, this ratio decreased to a negative value (−0.09) from the initial 0.14. In oriented samples, the degree of polarization remained at 0.68 for BChlc, and changed from 0.25 to −0.40 for the baseplate BChla by excitation light whose electric vector was parallel to the longest axis of chlorosomes. In the latter case, there was a shift from 0.30 to −0.55 by excitation perpendicular to the longest axis. Time-resolved fluorescence polarization spectra clearly indicated extensive changes in polarization plane accompanied by energy transfer. The directions of polarization plane of emission from oriented samples were mostly dependent on chlorosome orientation in the gel but not on that of the polarization plane of excitation light. Orientations of the dipole moment of fluorescence components was consistent with that of absorption components as determined by the linear dichroism (Matsuura et al. (1993) Photochem. Photobiol. 57: 92–97). A model for molecular organization of BChlc anda in chlorosomes is proposed based on anisotropic optical properties.
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    URL: http://dx.doi.org/10.1007/BF02184159
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    Evolution of heliobacteria: Implications for photosynthetic reaction center complexes (1994)
    Springer
    Photosynthesis research 41 (1994), S. 285-294 
    Details
    ISSN: 1573-5079
    Keywords: heliobacteria ; reaction center ; photosynthesis ; 16S rRNA sequence ; cyanobacteria ; Gram-positive bacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The evolutionary position of the heliobacteria, a group of green photosynthetic bacteria with a photosynthetic apparatus functionally resembling Photosystem I of plants and cyanobacteria, has been investigated with respect to the evolutionary relationship to Gram-positive bacteria and cyanobacteria. On the basis of 16S rRNA sequence analysis, the heliobacteria appear to be most closely related to Gram-positive bacteria, but also an evolutionary link to cyanobacteria is evident. Interestingly, a 46-residue domain including the putative sixth membrane-spanning region of the heliobacterial reaction center protein shows rather strong similarity (33% identity and 72% similarity) to a region including the sixth membrane-spanning region of the CP47 protein, a chlorophyll-binding core antenna polypeptide of Photosystem II. The N-terminal half of the heliobacterial reaction center polypeptide shows a moderate sequence similarity (22% identity over 232 residues) with the CP47 protein, which is significantly more than the similarity with the Photosystem I core polypeptides in this region. An evolutionary model for photosynthetic reaction center complexes is discussed, in which an ancestral homodimeric reaction center protein (possibly resembling the heliobacterial reaction center protein) with 11 membrane-spanning regions per polypeptide has diverged to give rise to core of Photosystem I, Photosystem II, and of the photosynthetic apparatus in green, purple, and heliobacteria.
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    URL: http://dx.doi.org/10.1007/BF02184169
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    The photoproduction of superoxide radicals and the superoxide dismutase activity of Photosystem II. The possible involvement of cytochrome b559 (1994)
    Springer
    Photosynthesis research 41 (1994), S. 327-338 
    Details
    ISSN: 1573-5079
    Keywords: photosynthesis ; Photosystem II ; superoxide radical ; superoxide dismutase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In the present study the light induced formation of superoxide and intrinsic superoxide dismutase (SOD) activity in PS II membrane fragments and D1/D2/Cytb559-complexes from spinach have been analyzed by the use of ferricytochrome c (cyt c(III)) reduction and xanthine/xanthine oxidase as assay systems. The following results were obtained: 1.) Photoreduction of Cyt c (III) by PS II membrane fragments is induced by addition of sodium azide, tetracyane ethylene (TCNE) or carbonylcyanide-p-trifluoromethoxy-phenylhydrazone (FCCP) and after removal of the extrinsic polypeptides by a 1M CaCl2-treatment. This activity which is absent in control samples becomes completely inhibited by the addition of exogenous SOD. 2.) The TCNE induced cyt c(III) photoreduction by PS II membrane fragments was found to be characterized by a half maximal concentration of c1/2=10 μM TCNE. Simultaneously, TCNE inhibits the oxygen evolution rate of PS II membrane fragments with c1/2≈ 3 μM. 3.) The photoproduction of O2 − is coupled with H+-uptake. This effect is diminished by the addition of the O2 −-trap cyt c(III). 4.) D1/D2/Cytb559-complexes and PS II membrane fragments deprived of the extrinsic proteins and manganese exhibit no SOD-activity but are capable of producing O2 − in the light if a PS II electron donor is added. Based on these results the site(s) of light induced superoxide formation in PS II is (are) inferred to be located at the acceptor side. A part of the PS II donor side and Cyt b559 in its HP-form are proposed to provide an intrinsic superoxide dismutase (SOD) activity.
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    URL: http://dx.doi.org/10.1007/BF00019410
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    Thermoluminescence as a probe of Photosystem II in intact leaves: Non-photochemical fluorescence quenching in peas grown in an intermittent light regime (1994)
    Springer
    Photosynthesis research 41 (1994), S. 371-379 
    Details
    ISSN: 1573-5079
    Keywords: photosynthesis ; chlorophyll fluorescence ; high energy-state quenching ; calcium release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We have measured thermoluminescence (TL) and chlorophyll fluorescence from leaves of peas grown under an intermittent light regime (IML) and followed changes in those leaves during greening. IML peas show low variable fluorescence and a certain capacity for reversible non-photochemical quenching. It has been suggested that reversible quenching may be caused by pH-dependent release of Ca2+ from Photosystem II (PS II) (Krieger and Weis (1992) Photosynthetica 27: 89–98). Under conditions in which reversible non-photochemical quenching occurs, a TL band at around 50 °C is observed, in the presence of DCMU, in IML leaves. A band in this temperature range has previously been observed in PS II depleted of Ca2+ (Ono and Inoue (1989) Biochimica et Biophysica Acta 973: 443–449). The 50 °C band disappears upon dark adaptation. In mature leaves, no significant band is seen at 50 °C. It is concluded that, in IML leaves, reversible quenching may be related to the release of Ca2+ from Photosystem II. However, it seems that in the mature system, under most conditions, such release does not contribute significantly to quenching
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    URL: http://dx.doi.org/10.1007/BF02183039
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    Measurements of mesophyll conductance, photosynthetic electron transport and alternative electron sinks of field grown wheat leaves (1994)
    Springer
    Photosynthesis research 41 (1994), S. 397-403 
    Details
    ISSN: 1573-5079
    Keywords: electron transport rate ; mesophyll conductance to CO2 diffusion ; photosynthesis ; photorespiration
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Photosynthetic electron transport drives the carbon reduction cycle, the carbon oxidation cycle, and any alternative electron sinks such as nitrogen reduction. A chlorophyll fluorescence— based method allows estimation of the total electron transport rate while a gas-exchange-based method can provide estimates of the electron transport needed for the carbon reduction cycle and, if the CO2 partial pressure inside the chloroplast is accurately known, for the carbon oxidation cycle. The gas-exchange method cannot provide estimates of alternative electron sinks. Photosynthetic electron transport in flag leaves of wheat was estimated by the fluorescence method and gasexchange method to determine the possible magnitude of alternative electron sinks. Under non-photorespiratory conditions the two measures of electron transport were the same, ruling out substantial alternative electron sinks. Under photorespiratory conditions the fluorescence-based electron transport rate could be accounted for by the carbon reduction and carbon oxidation cycle only if we assumed the CO2 partial pressure inside the chloroplasts to be lower than that in the intercellular spaces of the leaves. To further test for the presence of alternative electron sinks, carbon metabolism was inhibited by feeding glyceraldehyde. As carbon metabolism was inhibited, the electron transport was inhibited to the same degree. A small residual rate of electron transport was measured when carbon metabolism was completely inhibited which we take to be the maximum capacity of alternative electron sinks. Since the alternative sinks were small enough to ignore, the comparison of fluorescence and gas-exchange based methods for measuring the rate of electron transport could be used to estimate the mesophyll conductance to CO2 diffusion. The mesophyll conductance estimated this way fell as wheat flag leaves senesced. The age-related decline in photosynthesis may be attributed in part to the reduction of mesophyll conductance to CO2 diffusion and in part to the estimated decline of ribulose 1,5-bisphosphate carboxylase amount.
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    URL: http://dx.doi.org/10.1007/BF02183042
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  • 100
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    Changes in the photosynthetic light response curve during leaf development of field grown maize with implications for modelling canopy photosynthesis (1994)
    Springer
    Photosynthesis research 42 (1994), S. 217-225 
    Details
    ISSN: 1573-5079
    Keywords: photosynthesis ; leaf age ; maize
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Changes in the photosynthetic light-response curve during leaf development were determined for the fourth leaf of maize crops sown on 23 April and 10 June. Temperatures were unusually mild during late spring/early summer and neither crop experienced chilling damage. The concept of thermal time was used to take into account the effects of different temperature regimes on developmental stage, thereby enabling photosynthetic light-response data to be combined for both crops to describe the general response. Large variations in the upper asymptote (Asat) and convexity (Θ) of the light-response curve occurred during leaf development, but the maximum quantum yield of CO2 assimilation remained relatively constant throughout. Dark respiration rates showed a small but significant decrease with leaf age and generally ranged between 5 and 10% of Asat. A simple mathematical model was developed to assess the sensitivity of daily leaf photosynthesis (AL) to reductions in the Asat, Θ and the initial slope (Φ) of the light-response curve at different stages of leaf development. On bright sunny days, and at all developmental stages, AL was ca. twice as sensitive to reductions in Asat than to reductions in Φ and Θ. In overcast conditions, however, all three parameters contributed significantly to reductions in leaf photosynthesis, although the contribution of Φ was greatest during early leaf growth, while older leaves were most sensitive to depressions in Asat. The implications of these results for modelling the sensitivity of canopy photosynthesis to chill-induced photoinhibition of the light-response curve are discussed.
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    URL: http://dx.doi.org/10.1007/BF00018264
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