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  • Articles  (37)
  • wheat
  • Springer  (37)
  • Springer Nature
  • Chemistry and Pharmacology  (26)
  • Medicine  (11)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 50 (1994), S. 571-575 
    ISSN: 1420-9071
    Keywords: Ancient DNA ; archaeobotany ; carbonized grain ; DNA sequences ; glutenin alleles ; seed proteins ; Triticum ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract We have used hybridization analysis to detect ancient DNA in wheat seeds collected from three archaeological sites in Europe and the Middle East. One of these samples, carbonizedT. spelta dated to the first millennium BC, has yielded PCR products after amplification with primers directed at the leader regions of the HMW (high molecular weight) glutenin alleles. Sequences obtained from these products suggest that the DNA present in the Danebury seeds is chemically damaged, as expected for ancient DNA, and also indicate that it should be possible to study the genetic variability of archaeological wheat by ancient DNA analysis. Finally, we describe a PCR-based system that enables tetraploid and hexaploid wheats to be distinguished.
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  • 2
    ISSN: 1420-9071
    Keywords: Hydroxamic acid ; cereals ; maize ; wheat ; aphids ; greenbug
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary 2-β-Glucosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA-Glc), the main hydroxamic acid from maize and wheat, and its aglucone, decreased survival ofSchizaphis graminum reared on artificial diets. Both compounds were toxic for aphids and acted as feeding deterrents, at concentrations as low as 1 mM. The natural concentrations of glucosides of hydroxamic acids in wheat leaves reach up to 6 mmoles/kg fresh weight, thus falling within the range in which DIMBOA-Glc causes delecterious effects to diet-fed aphids.
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  • 3
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    European journal of nutrition 22 (1983), S. 27-33 
    ISSN: 1436-6215
    Keywords: wheat ; lysine ; carnitine ; lipids ; mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Medicine
    Description / Table of Contents: Zusammenfassung 32 abgesetzte männliche Albinoratten wurden in 4 Gruppen eingeteilt, um die Wirkung einer lysinarmen Weizendiät (AW), einer Weizendiät mit 0,4 % Lysin (LW) oder 0,2 % Carnitin (CW) sowie einer Caseindiät auf den Stoffwechsel von Lipiden in verschiedenen Geweben zu untersuchen. Nach 8 Wochen Fütterung der verschiedenen Diäten unter Anwendung der „paired feeding technique“ wurden Veränderungen in den Gesamtlipiden, den Lipidbestandteilen, den einzelnen Fettsäuren und dem Lipidgehalt der Mitochondrien des Herzens, der Skelettmuskeln, der Lungen und des Fettgewebes der Tiere bestimmt. Die lysinarme Weizendiät (AW) bewirkte eine Lipidanreicherung (vor allem an Acylglyzerinen) im Herzen, in der Leber, den Skelettmuskeln sowie eine Lipidabnahme im Fettgewebe. Die Diäten mit 0,4 % Lysin (LW) oder 0,2 % Carnitin (CW) zeitigten die entgegengesetzte Wirkung, wobei CW wirkungsvoller erschien als LW. LW und CW erhöhten die relativen Anteile von C14∶0-, C16∶0- und C16∶1-Fettsäuren und verkleinerten diejenigen von C18∶1-, C18∶2- und C18∶3-Fettsäuren, während die Anteile unter der AW- und Caseindiät ab- bzw. zunahmen. Die Fettsäurezusammensetzung des Fettgewebes war bei allen Gruppen gleich. Die AW-Diät vergrößerte die relativen Anteile von C14∶0- und C20∶4- und verringerte die von C16∶0-, C16∶1- und C18∶3-Fettsäuren in den Lungen. Die AW-Ergänzungsdiäten verringerten die relativen Anteile von C16∶0-, C16∶1-, C18∶3-sowie auch der C18∶1-Fettsäuren. Der Lipidgehalt der Mitochondrien von Leber, Herz, Skelettmuskeln und Lunge verringerte sich unter der AW-Diät und erhöhte sich unter den LW- und CW-Diäten.
    Notes: Summary 32 weanling male albino rats were divided into 4 groups to study the effects of lysine-deficient wheat diet (AW) and AW supplemented with either 0.4 % lysine (LW) or 0.2 % carnitine (CW) as compared to casein diet on metabolism of lipids in various tissues. LW, CW and casein diet groups were pair-fed with AW group. Changes in total lipids, lipid components, individual fatty acids, mitochondrial content in liver, heart, skeletal muscles, lungs and adipose tissue were determined after 8 weeks of feeding. AW diet resulted in accumulation of lipids (mainly acylglycerols) in heart, liver, skeletal muscles and depletion in adipose tissue. The LW and CW diets reversed the effects of AW diet, the CW being more effective than LW diet. The LW and CW diets increased the relative proportion of C 14∶0, C 16∶0, C 16∶1 and decreased that of C18∶1, C18∶2, C18∶3 fatty acids which were decreased and increased, respectively, on the AW and casein diets. The fatty acids composition of adipose tissue was the same in all the groups. The AW diet increased the relative proportions of C 14∶0, C 20∶4 and decreased that of C 16∶0, C 16∶1, C 18∶3 fatty acids in the lungs. Supplemented AW diet decreased the relative proportions of the former group and increased that of the later group including C 18∶1 fatty acid also. The mitochondrial content of liver, heart, skeletal muscles and lungs was decreased on AW and reversed on LW and CW diets.
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  • 4
    ISSN: 1573-0832
    Keywords: deoxynivalenol ; enzyme immunoassay ; feed ; maize ; mycotoxins ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Samples of wheat (n = 25) and maize (n = 30) for animal consumption, collected in 1997 after harvest from western Romania, were analyzed by enzyme immunoassays for mycotoxin contamination. Toxins analyses included deoxynivalenol (DON), 3-acetylDON, 15- acetylDON, fusarenone X (FX), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), zearalenone (ZEA), fumonisin B1 (FB1), aflatoxin B1 (AFB1), ochratoxin A (OA), and citrinin (CT). DON and acetylDONs were the major contaminants in wheat (100%) and maize (46%). Median values for DON, 3-acetylDON, and 15-acetylDON were 880 μg kg-1, 66 μg kg- 1, and 150 μg kg-1 in wheat, and 890 μg kg-1, 180 μg kg-1, and 620 μg kg- 1 in maize, respectively. Additionally, 3,15-diacetylDON was detected in some samples by HPLC-EIA analysis. All samples were negative for FX (〈150 μg kg-1). T-2 was found in wheat (n = 6) and maize (n = 1) at levels between 13 and 63 μg kg- 1. DAS (2.6 μg kg-1) was found in one maize sample. ZEA occurred in all wheat and in four maize samples, median values were 10 μg kg-1 and 250 μg kg-1, respectively. One maize sample contained FB1 (140 μg kg-1). All samples were AFB1-negative (〈4 μg kg-1). OA was found in one wheat sample (37 μg kg- 1), CT was found in one maize sample (580 μg kg- 1). This first reported natural occurrence of a range of mycotoxins in Romanian feeding stuff shows that DON and acetyl DONs may be present at levels which may affect animal production.
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  • 5
    ISSN: 1573-0832
    Keywords: odors ; volatiles ; microflora ; fungi ; wheat ; seasonality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The fungal odor compounds 3-methyl-l-butanol, l-octen-3-ol and 3-octanone were monitored in nine experimental bins in Winnipeg, Manitoba containing a hard red spring wheat during the autumn, winter and summer seasons of 1984–85. Quality changes were associated with seed-borne microflora and moisture content in both ventilated and non-ventilated bins containing wheat of 15.6 and 18.2% initial moisture content. All three odor compounds occurred in considerably greater amounts in bulk wheat in non-ventilated than in ventilated bins, particularly in those with wheat having 18.2% moisture content. The presence of these compounds usually coincided with infection of the seeds by the fungi Alternaria alternata (Fr.) Keissler, Aspergillus repens DeBarry, A. versicolor (Vuill.) Tiraboschi, Penicillium crustosum Thom, P. oxalicum Currie and Thom, P. aurantiogriseum Dierckx, and P. citrinum Thom. High production of all three odor compounds in damp wheat stored in non-ventilated bins was associated with heavy fungal infection of the seeds and reduction in seed germinability. High initial moisture content of the harvested grain accelerated the production of all three fungal volatiles in non-ventilated bins.
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  • 6
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    Mycopathologia 111 (1990), S. 181-189 
    ISSN: 1573-0832
    Keywords: mycotoxin ; ochratoxin ; Penicillium ; storage ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Eleven-kilogram parcels of HY-320 wheat, a cultivar of the new Canada Prairie Spring class, were kept at 15 and 19% initial moisture contents (IMC) in simulated storage in a Manitoba farm granary for 60 weeks to determine biotic and abiotic changes and mycotoxin production. Ochratoxin A reached a maximum of 0.24 ppm by week 20 in the 19% IMC wheat, but was absent in the 15% IMC wheat; no other mycotoxins were detected. Temperature, moisture content, O2 and CO2 levels, fat acidity values, seed germination, microfloral incidence and abundance, and the presence of other mycotoxins were monitored. Principal component analysis of all variables showed that the first principal components accounted for 32–41% of the system variability, and contained the ochratoxin A variable. Ochratoxin A was produced in moist grain that had decreased seed germination andAltermaria activity, and high fungal activity byPenicillium andAspergillus versicolor. Compared to other stored cereals previously studied, HY-320 wheat would be ranked in a low-risk category for mycotoxin formation, based on the ochratoxin A levels observed.
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  • 7
    ISSN: 1573-0832
    Keywords: Penicillium griseofulvum ; patulin ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Sixty-four wheat samples from Spanish flour factories were screened for patulin and patulin-producing moulds. None of them was found to contain any patulin, whereas samples experimentally contaminated with this toxin proved it to be highly unstable. On the other hand, Penicillium griseofulvum was the only in vitro patulin-producing species found (19 samples). Mould growth in the samples was investigated by using yeast-sucrose medium (YES) and high-performance liquid chromatography (HPLC) to measure the amounts of toxin produced during 40 day's incubation at 20 and 28°C. The highest yield rate of patulin was obtained between the 20th and 30th day of incubation; such a rate, however, was very low throughout the vigorous growth phase, during the first 20 days of incubation. The more appropriate temperature for incubation and patulin production was 28 °C. We also investigated the influence of other incubation conditions in the yield and found stationary dark cultures to be more efficient that shaken or fermentation cultures in YES medium. The best patulin yield achieved was 11.9 mg in the culture broth and 6.3 mg in the mycelium from 100 ml of medium.
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  • 8
    ISSN: 1573-0832
    Keywords: Fusarium ; mycotoxins ; occurrence ; trichothecenes ; wheat ; zearalenone ; deoxynivalenol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Wheat for human consumption (140 samples) was collected after harvest from all regions of Bulgaria. The 1995 crop year was characterized by heavy rainfall in the spring and summer months. The internal mycoflora of wheat samples was dominated by Fusarium spp. and Alternaria spp., and storage fungi were rarely present. The samples were analysed for contamination with Fusarium mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), T-2 Toxin (T-2), diacetoxyscirpenol (DAS), and zearalenone (ZEA), using enzyme immunoassay methods. DON and ZEA were the predominant toxins, with a contamination frequency of 67% and 69%, respectively. The average levels of these toxins in positive samples were 180 μg/kg (DON) and 17 μg/kg (ZEA), maximum concentrations were 1800 μg kg−1 and 120 μg kg−1, respectively. Acetyl derivatives of DON, namely 3-AcDON and 15-AcDON, were found in 2.1 % and 0.7% of the samples, at at maximum level of about 100 μg kg−1. Only one sample was positive for T-2 (55 μg/kg), DAS was not detected. This is the first report about the natural occurrence of a range of Fusarium mycotoxins in wheat for human consumption in Bulgaria.
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  • 9
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    Mycopathologia 68 (1979), S. 131-137 
    ISSN: 1573-0832
    Keywords: Erysiphe graminis f. sp.tritici ; powdery mildew fungus ; resistance ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract During primary infection by conidia ofErysiphe graminis f. sp.tritici, three mechanisms of resistance operate in first leaves of 8-day-old seedlings of both resistant and susceptible wheats. The first mechanism, operating at the penetration site, is responsible for the failure of penetrations attempted by primary germ tubes (PGT). The second mechanism is concerned with the abortion of haustoria in normal-appearing host cells. The third mechanism relates to the abortion of haustoria and the hypersensitivity of the penetrated host cells. With the inoculum-level of 19–24 conidia/mm2, the three mechanisms together prevented 89.3 % of the attempted penetrations by PGT from producing normal haustoria in resistant wheat Purdue 5752C1-7-5-1 and 37.4 % in the susceptible wheat Vermillion. The first mechanism accounted for the prevention of 73.3 % of the attempted PGT penetrations on Purdue 5752C1-7-5-1 and 36 % on Vermillion. The second mechanism was responsible for stopping 19 % of all the successful penetrations in Purdue 5752C1-7-5-1 and 0.8 % in Vermillion. The third mechanism accounted for the failure of 41 % of all the successful penetrations in Purdue 5752C1-7-5-1 and 1.4% in Vermillion. Thirty-six hours after inoculation, 10.7% of all the attempted PGT penetrations appeared to be developing normally in first leaves of 8-day-old seedlings of resistant wheat Purdue 5752C1-7-5-1 as compared to 62.6 % in the susceptible wheat Vermillion. This appears to be the first report showing the relative effectiveness of various mechanisms of resistance concerning any powdery mildew fungus.
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  • 10
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    Cellular and molecular life sciences 46 (1990), S. 1016-1017 
    ISSN: 1420-9071
    Keywords: In vitro absorption ; calcium ; wheat ; Bengal gram
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The in vitro absorption of calcium from the duodenum was significantly less in a group of rats fed on a wheat diet than in a group fed a wheat and Bengal gram (70∶30) diet.
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  • 11
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    Biochemical genetics 15 (1977), S. 47-57 
    ISSN: 1573-4927
    Keywords: wheat ; chromosomes ; gibberellin ; enzymes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The three enzymes, α-amylase, peroxidase, and acid phosphatase, are among those released by the aleurone of bread wheat, Triticum aestivum, as a direct response to gibberellins (GA) from the embryo during germination. Aneuploid genotypes are used to investigate the chromosomal location, nature, and extent of genetic control of the release of these enzymes in endosperms after induction by exogenous GA. Ditelosomics demonstrate the effect of removal of known chromosome arms, and tetrasomics show the effect of duplication of chromosome pairs. Quantitative analysis demonstrates complex control systems over and above those previously found using zymogram techniques. For α-amylase, chromosome arms with net promoter effects and chromosomes with net inhibitor effects were found. These effects were not chromosome-dosage responsive, unlike the promoter-inhibitor system found for acid phosphatase control. Peroxidase levels in the endosperms were generally high in both types of aneuploids. With one exception, all chromosomes showing involvement as ditelosomics showed a similar effect as tetrasomics, indicating that in the euploid a balanced state restricting, rather than promoting, peroxidase levels existed.
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  • 12
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    Biochemical genetics 19 (1981), S. 237-254 
    ISSN: 1573-4927
    Keywords: wheat ; barley ; addition lines ; isozymes ; genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Zymogram analysis was used to identify the barley chromosomes that carry the structural genes for particular isozymes. Wheat, barley, and wheatbarley hybrid derivative lines (which contained identified barley chromosomes) were tested by gel electrophoresis for isozymes of particular enzymes. It was found that barley chromosome 4 carries structural genes for acid phosphatase and β amylase isozymes, barley chromosome 5 carries genes for phosphoglucose isomerase and malate dehydrogenase isozymes, and that barley chromosome 2 carries a gene for at least one glucose-6-phosphate dehydrogenase protomer. These results reinforce previous conclusions that barley chromosome 4 shows homoeology with wheat chromosome group 4 and that barley chromosome 5 shows homoeology with wheat chromosome group 1.
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  • 13
    ISSN: 1573-1561
    Keywords: Allelochemicals ; no-tillage ; conventional-tillage ; soils ; wheat ; Triticum aestivum ; mass spectrometry ; Petri-dish bioassay ; fatty acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Putative allelochemicals found in the soil of no-tillage and conventional-tillage wheat plots near Stillwater, Oklahoma, were obtained by a mild alkaline aqueous extraction procedure, bioassayed to determine their biological activity, purified, and analyzed with a capillary gas chromatography-mass spectrometry-data analysis system. The most significant inhibition was found in bioassays of extracts from soil collected immediately after harvest in June, July, and August. No-tillage soils produced significant inhibition during the rest of the year also. Mass spectrometry showed fatty acids as the most abundant compounds. However, when bioassayed authentic samples of the five free fatty acids showed no significant biological activity toward wheat.
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  • 14
    ISSN: 1573-1561
    Keywords: Cover crops ; wheat ; Triticum aestivum ; soybean ; Glycine max ; soil extracts ; germination bioassays ; phenolic acids ; hydroxamic acids ; allelopathy ; slope analysis ; ivy-leaved morning glory ; Ipomoea hederacea ; crimson clover ; Trifolium incarnalum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The primary objective of this research was to determine if soil extracts could be used directly in bioassays for the detection of allelopathic activity. Here we describe: (1) a way to estimate levels of allelopathic compounds in soil; (2) how pH, solute potential, and/or ion content of extracts may modify the action of allelopathic compounds on germination and radicle and hypocotyl length of crimson clover (Trifolium incarnatum L.) and ivyleaved morning glory (Ipomoea hederacea L. Jacquin.); and (3) how biological activity of soil extracts may be determined. A water-autoclave extraction procedure was chosen over the immediate-water and 5-hr EDTA extraction procedures, because the autoclave procedure was effective in extracting solution and reversibly bound ferulic acid as well as phenolic acids from wheat debris. The resulting soil extracts were used directly in germination bioassays. A mixture of phenolic acids similar to that obtained from wheat-no-till soils did not affect germination of clover or morning glory and radicle and hypocotyl length of morning glory. The mixture did, however, reduce radicle and hypocotyl length of clover. Individual phenolic acids also did not inhibit germination, but did reduce radicle and hypocotyl length of both species. 6-MBOA (6-methoxy-2,3-benzoxazolinone), a conversion product of 2-o-glucosyl-7-methoxy-1,4-benzoxazin-3-one, a hydroxamic acid in living wheat plants, inhibited germination and radicle and hypocotyl length of clover and morning glory. 6-MBOA, however, was not detected in wheat debris, stubble, or soil extracts. Total phenolic acids (FC) in extracts were determined with Folin and Ciocalteu's phenol reagent. Levels of FC in wheat-conventionaltill soil extracts were not related to germination or radicle and hypocotyl length of either species. Levels of FC in wheat-no-till soil extracts were also not related to germination of clover or morning glory, but were inversely related to radicle and hypocotyl length of clover and morning glory. FC values, solute potential, and acidity of wheat-no-till soil extracts appeared to be independent (additive) in action on clover radicle and hypocotyl length. Radicle and hypocotyl length of clover was inversely related to increasing FC and solute potential and directly related to decreasing acidity. Biological activity of extracts was determined best from slopes of radicle and hypocotyl length obtained from bioassays of extract dilutions. Thus, data derived from the water-autoclave extraction procedure, FC analysis, and slope analysis for extract activity in conjunction with data on extract pH and solute potential can be used to estimate allelopathic activity of wheat-no-till soils
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  • 15
    ISSN: 1573-1561
    Keywords: Kairomone ; biological control ; cabbage ; wheat ; Diuraphis noxia ; Brevicoryne brassicae ; olfactometer ; infochemical ; preference ; host plants
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Diaeretiella rapae (M'Intosh) (Hymenoptera: Aphidiidae) is a parasitoid of several aphid species, including the Russian wheat aphid (RWA),Diuraphis noxia (Mordvilko), and the cabbage aphid (CA).Brevicoryne brassicae (L.). The response of matedD. rapae females to odors from wheat, cabbage, and plant-host complexes was investigated using a four-choice olfactometer. Experienced parasitoids, but not inexperienced females, responded positively to odors of the wheat-RWA complex in a no-choice test. In choice tests, experienced parasitoids did not respond to odors of uninfested cabbage and wheat leaves, but did respond positively to aphid-infested plants and to aphids alone. The response ofD. rapae to the cabbage-CA complex and to CA alone was significantly greater than to the wheat-RWA complex and RWA alone, suggesting an innate odor preference for crucifer-feeding aphids.
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  • 16
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    Journal of chemical ecology 23 (1997), S. 2695-2705 
    ISSN: 1573-1561
    Keywords: Defense ; herbivory ; aphids ; wheat ; Gramineae ; hydroxamic acids ; Defense theory ; Carbon/Nutrient theory
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Hydroxamic acids (Hx) are natural products of Gramineae that are associated with cereal resistance to pests. We aimed at characterizing the induction of Hx accumulation in seedlings of wheat,Triticum aestivum, by short-term infestation of the cereal aphid,Rhopalosiphum padi. A load of 25 aphids increased significantly the Hx levels in the infested primary leaf in comparison with control levels. Lower loads did not increase Hx concentration. Aphid infestation lasting 16 hr did not elicit induction of Hx, even after a time-lag of 32 hr to allow the expression of any induced response. Forty-eight hours was the minimum duration of aphid infestation required to trigger Hx induction. The age of the infested tissue (the primary leaf) did not affect induction. Similar increases of Hx were found in unfolding, expanding, and totally expanded primary leaves. It was determined that the regime of nutrient supply (N-intensive nutritive solutions at low and high concentration) to wheat seedlings had no effect on the magnitude of the aphid-induced Hx (N-based secondary metabolites). Results obtained are discussed in the framework of general theories of plant defense allocation.
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  • 17
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    Biochemical genetics 16 (1978), S. 831-853 
    ISSN: 1573-4927
    Keywords: Triticum aestivum L. ; wheat ; storage proteins ; gliadins ; gel electrophoresis ; endosperm ; dominant genes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Inheritance of gliadin components unique to three different varieties of common wheat (Triticum aestivum L.) was studied in F1 and F2 seeds of intervarietal crosses using protein patterns obtained by polyacrylamide gel electrophoresis in aluminum lactate buffer (pH 3.2). The patterns of F1 seeds of the crosses Cheyenne × Justin and INIA 66R × Justin evidenced all the bands present in the patterns of the parents; band intensities reflected gene dosage levels dependent on whether the contributing parent was maternal or paternal in accordance with the triploid nature of endosperm tissue. Most of the gliadin components examined segregated in accordance with control by a single dominant gene, but in two instances single bands in the one-dimensional electrophoretic patterns segregated in the F2 as expected if controlled by two genes. A method of two-dimensional electrophoresis was developed that resolved these apparently single bands into two components each, which could segregate independently. Linkage analysis provided evidence of codominant alleles and closely linked genes coding for gliadin protein components in both coupling and repulsion situations. The gliadin protein components seem to be coded for by clusters of genes located on chromosomes of homoeologous groups 1 and 6 in hexaploid wheats.
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  • 18
    ISSN: 1573-4927
    Keywords: wheat ; seed protein genes ; restriction-fragment length polymorphism, prolamins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Restriction enzyme digests of DNA from nullisomic-tetrasomic and intervarietal chromosome substitution lines of wheat were probed with a high molecular weight (HMW) glutenin cDNA. Three restriction endonucleases were used to investigate restriction-fragment differences among five wheat varieties. The results suggest that the hybridizing fragments contain single gene copies and permit the identification of the subunit encoded by each gene. Restriction-fragment variation associated with previously established allelic differences between varieties was observed. Also, there is a clear relationship between the electrophoretic mobility of a HMW subunit and the length of the central repetitive section of the gene encoding it. These results are discussed with reference to the evolution of the HMW glutenin gene family and the uses of restriction-fragment variation in plant breeding and genetics.
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  • 19
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    Biochemical genetics 25 (1987), S. 591-602 
    ISSN: 1573-4927
    Keywords: trypsin inhibitor ; homoeoloci ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The aneuploids of Chinese Spring wheat have been used to locate the genes(Ti-2) coding for a novel series of trypsin inhibitors to the long arms of the homoeologous group 5 chromosomes. Three allelic variants at the 5D locus were detected in a limited survey among wheat varieties, but no variation at the loci on either chromosome 5A or chromosome 5B was detected. Homoeoloci were found in a number of alien relatives, and in the majority of cases, these were present on the group 5 homoeologue. However, inAegilops umbellulata, theTi-U2 locus was located on a chromosome presumed to belong to homoeologous group 1. NoHordeum vulgare orH. chilense Ti-2 gene was expressed in a wheat background. This new marker will be especially useful as a screening mechanism for nullisomy of chromosome 5B in work aimed at introgression of alien chromatin into wheat.
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  • 20
    ISSN: 1573-4927
    Keywords: wheat ; gliadins ; gel electrophoresis ; evolution ; genetic analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The gliadin composition of 78 spring durum wheat varieties has been studied by one-dimensional (Al-lactate,pH 3.1) and two-dimensional (first dimension, Al-lactate,pH 3.1; second dimension, sodium dodecyl sulfate-polyacrylamide gel) electrophoresis. Analysis of hybrids has shown that all components of the α zone of gliadin spectra are inherited together as blocks and are, probably, coded for by a cluster of tightly linked genes located on chromosome 6A. Fourteen variants of gliadin blocks have been identified, which can be classified into five families on the basis of component composition. All families but one have analogues among chromosome 6A-controlled blocks of bread wheat. The results indicate that some of the genome A diploid genotypes that were ancestors of durum wheats were also ancestors of bread wheats and that polyploid wheats were produced by repeated allopolyploidization events, as has been suggested earlier.
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  • 21
    ISSN: 1573-4927
    Keywords: wheat ; gliadins ; gel electrophoresis ; evolution ; genetic analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The gliadin composition of 78 spring durum wheat varieties has been studied by one-dimensional (Al-lactate,pH 3.1) and two-dimensional (first dimension, Al-lactate,pH 3.1; second dimension, sodium dodecyl sulfate-polyacrylamide gel) electrophoresis. Analysis of hybrids has shown that all components of the α zone of gliadin spectra are inherited together as blocks and are, probably, coded for by a cluster of tightly linked genes located on chromosome 6A. Fourteen variants of gliadin blocks have been identified, which can be classified into five families on the basis of component composition. All families but one have analogues among chromosome 6A-controlled blocks of bread wheat. The results indicate that some of the genome A diploid genotypes that were ancestors of durum wheats were also ancestors of bread wheats and that polyploid wheats were produced by repeated allopolyploidization events, as has been suggested earlier.
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  • 22
    ISSN: 1573-4943
    Keywords: Amino acid sequence ; wheat ; wounding ; plant defence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The amino acid sequence of wheatwin1, a monomeric protein of 125 residues isolated from wheat kernel (variety S. Pastore), is reported. Wheatwin1 is highly homologous (95%) to barwin, a protein from barley seed, which was shown to be related to the C-terminal domain of two proteins encoded by the wound-induced geneswin1 andwin2 in potato and to a protein encoded by the same domain of the hevein gene (hev1) in rubber tree. Similarly to barwin, wheatwin1 contains six cysteine residues all linked in disulfide bridges and the N-terminal residue is pyroglutamate. Moreover, structural studies performed on wheatwin1 andwin1 protein by predictive methods demonstrated that these proteins and barwin are closely related in the secondary structure also. The high level of homology found with the product ofwin1,win2, andhev1 genes strongly suggests that barwin and wheatwin1 play a common role in the mechanism of plant defence.
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  • 23
    ISSN: 1573-4943
    Keywords: Trypsin inhibitor ; wheat ; primary structure ; reactive site ; Bowman-Birk
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The sequence of a trypsin inhibitor, isolated from wheat endosperm, is reported. The primary structure was obtained by automatic sequence analysis of the S-alkylated protein and of purified peptides derived from chemical cleavage by cyanogen bromide and digestion withStaphylococcus aureus V8 protease. This protein, named wheat trypsin inhibitor (WTI), which is comprised of a total of 71 amino acid residues, has 12 cysteines, all involved in disulfide bridges. The primary site of interaction (reactive site) with bovine trypsin has been identified as the dipeptide arginyl-methionyl at positions 19 and 20. WTI has a high degree of sequence identity with a number of serine proteinase inhibitors isolated from both cereal and leguminous plants. On the basis of the findings presented, this protein has been classified as a single-headed trypsin inhibitor of Bowman-Birk type.
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  • 24
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    Journal of chemical ecology 19 (1993), S. 2453-2461 
    ISSN: 1573-1561
    Keywords: DIMBOA ; MBOA ; DIM2BOA ; M2BOA ; 2-amino-7-methoxy-3H-phenoxazin-3-one ; 2-amino-4,6,7-trimethoxy-3H-phenoxazin-3-one ; corn ; wheat ; soil microbial transformation ; phytotoxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The defensive cyclic hydroxamates 7-methoxy-2,4-dihydroxy-1,4(2H)-benzoxazin-3-one (DIMBOA) and 7,8-dimethoxy-2,4-dihydroxy-1,4(2H)-benzoxazin-3-one (DIM2BOA) of wheat and corn are transformed in nonsterile soil, via 6-methoxy-2(3H)-benzoxazolone (MBOA) and 6,7-dimethoxy-2(3H)-benzoxazolone (M2BOA) respectively, into 2-amino-7-methoxy-3H-phenoxazin-3-one and 2-amino-4,6,7-trimethoxy-3H-phenoxazin-3-one. The soil transformation is similar of that undergone by the rye metabolite 2(3H)-benzoxazolone (BOA) into 2-amino-3H-phenoxazin-3-one. The transformations to phenoxazinones are not observed in sterile soil. The 2-amino-3H-phenoxazin-3-one inhibits barnyard grass radicle elongation, but the methoxylated aminophenoxazinones are not significantly inhibitory.
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  • 25
    ISSN: 1573-1561
    Keywords: α-Amylase inhibitors ; trypsin inhibitors ; cereal endosperm ; wheat ; barley ; Spodoptera frugiperda ; digestive enzymes ; midgut proteases
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The α-amylase activity was determined throughout the larval development of Spodoptera frugiperda. Maximal activities with optimal pH in the range 8.5–9.5 were found in last instars. Protein preparations enriched in heterotetrameric inhibitors from wheat flour were active towards gut amylases from last instars, while those corresponding to homodimeric and monomeric inhibitors showed low inhibition levels. These results were further supported by testing purified members of each inhibitor type and by analyzing the effects of the inhibitors on the amylase isoenzyme pattern from native PAGE. High levels of trypsin-like activity were also found in gut extracts from last instars. Different genetic variants of the major barley trypsin inhibitor were active against this gut enzyme. None of the other larval digestive protease activities (chymotrypsin-like, elastase-like, leucine aminopeptidase-like, and carboxypeptidase A and B-like) were inhibited, indicating that the barley inhibitor is specific towards trypsin-like enzymes.
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  • 26
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    Journal of chemical ecology 26 (2000), S. 2141-2154 
    ISSN: 1573-1561
    Keywords: Allelopathy ; phenolic acids ; 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one ; DIMBOA ; GC-MS-MS ; wheat ; Triticum aestivum ; weed suppression ; annual ryegrass ; Lolium rigidum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Wheat allelopathy has potential for weed suppression. Allelochemicals were identified in wheat seedlings, and they were exuded from seedlings into agar growth medium. p-Hydroxybenzoic, trans-p-coumaric, cis-p-coumaric, syringic, vanillic, trans-ferulic, and cis-ferulic acids and 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA) were identified in both the shoots and roots of 17-day-old wheat seedlings and their associated agar growth medium. Wheat accessions with previously identified allelopathic activity tended to contain higher levels of allelochemicals than poorly allelopathic ones. The allelopathic compounds present in the shoots generally also were identified in the roots and in the agar medium. Allelochemicals were distributed differentially in wheat, with roots normally containing higher levels of allelochemicals than the shoots. When the eight allelochemicals were grouped into benzoic acid and cinnamic acid derivatives, DIMBOA, total coumaric, and total ferulic acids, the amount of each group of allelochemicals was correlated between the roots and the shoots. Most of the allelochemicals identified in the shoots and roots could be exuded by the living roots of wheat seedling into the agar growth medium. However, the amounts of allelochemicals in the agar growth medium were not proportional to those in the roots. Results suggest that wheat plants may retain allelochemicals once synthesized. The presence of allelochemicals in the agar growth medium demonstrated that wheat seedlings were able to synthesize and to exude phytotoxic compounds through their root system that could inhibit the root growth of annual ryegrass.
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  • 27
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    Journal of chemical ecology 12 (1986), S. 2011-2020 
    ISSN: 1573-1561
    Keywords: 6-Methoxybenzoxazolinone ; hydroxamic acids ; wheat ; photoperiod ; temperature
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract 6-Methoxybenzoxazolinone (6-MBOA), a compound derivable from some freshly growing plants, is known to stimulate reproduction in some mammals and birds. Winter wheat was studied under controlled laboratory conditions to determine the effects of photoperiod and temperature on derivable 6-MBOA content. Longer photoperiods decrease the amount of derivable 6-MBOA per gram of fresh material in 4-day-old wheat seedlings. Higher temperatures also decrease the amount of derivable 6-MBOA in 4-day-old wheat. 6-MBOA content decreases as the plant ages. Comparisons of only the first centimeter above the seed produced the same age-related result. 6-MBOA is concentrated in the meristematic region with decreasing amounts found in higher portions of the plant. Roots from 9-day-old plants contain 6-MBOA. Unsprouted wheat seeds contain negligible amounts of 6-MBOA. These results demonstrate that environmental variables have a significant effect on derivable 6-MBOA levels, but that under all the regimes studied, 6-MBOA is present in freshly sprouted wheat.
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  • 28
    ISSN: 1573-1561
    Keywords: Hessian fly ; Mayetiola destructor ; Diptera ; Cecidomyiidae ; oviposition stimulants ; wheat ; rye ; barley ; oat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract More than twice the number of mated female Hessian flies,Mayetiola destructor (Say) entered a zone within 1 cm of a paper strip treated with one plant equivalent (PE) of a chloroform extract of wheat foliar waxes compared to a strip treated with solvent only; females also stayed six times longer and laid 10 times more eggs on the strip treated with the wheat extract. Column chromatographic fractionation of the wheat extract and application of these fractions onto filter paper strips showed four fractions elicited significant numbers of eggs to be laid. Single, binary, and tertiary combinations of three of these fractions (two of the four fractions apparently contained similar compounds) were tested. The greatest numbers of eggs were laid on strips treated with the tertiary combination or the binary combination conaining the two most active fractions (3 and 6); three times the number of eggs were laid on strips treated with this binary combination than the sum of eggs laid on strips treated with these two fractions separately. A comparison of grasses and their extracts showed female Hessian flies laid greater numbers of eggs on wheat or rye than on barley or oat. Fractionated barley and oat extracts were tested for activity as for wheat, and a similar pattern was observed, i.e., the greatest numbers of eggs were laid on fractions 3 and 6. Dose-response tests, using these two fractions of wheat, barley, or oat showed the same threshold of activity for fraction 3 for all three extracts, i.e., 2 PE. In contrast, fraction 6 of wheat was active at the lowest dosage tested, 0.25 PE, while the same fraction of either barley or oat was not active until tested at a dosage of 2 PE. It appears that (at least) two chemicals in the foliar waxes of these grasses influence ovipositional behavior of female Hessian flies. Furthermore, given the similar foliar chemistry of these grasses and the strong synergistic interaction between fractions 3 and 6 shown for wheat extract, it is likely that the ovipositional preferences exhibited by female Hessian flies towards these grasses may be explained by quantitative differences in the amount(s) of the active chemical(s) in their respective fraction 6 (most polar fraction tested).
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  • 29
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    Journal of chemical ecology 18 (1992), S. 841-846 
    ISSN: 1573-1561
    Keywords: Rhopalosiphum padi ; Homoptera ; Aphididae ; wheat ; maize ; DIMBOA ; hydroxamic acids ; aphid honeydew
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract DIMBOA glucoside (2-O-/gb-D-glucopyranosyl-4-hydroxy-7-meth-oxy-1,4-benzoxazin-3-one), the main hydroxamic acid (Hx) in intact wheat plants, was detected in the honey dew ofRhopalosiphum padi feeding on seedlings of six wheat cultivars that differed in their concentration of Hx, suggesting that the chemical circulates in the phloem. Neither the aglucone (DIMBOA) nor its main breakdown product were found in any of the honeydew samples. Honey dew production by aphids caged on seedlings of the wheat cultivars and DIMBOA glucoside concentrations in the honeydew followed biphasic curves when plotted against Hx concentration, suggesting passive ingestion of the chemical from the phloem at low Hx concentrations and limited ingestion due to feeding deterrency by Hx in mesophyll cells at high Hx concentrations. The presence of plant toxins such as Hx glucosides in the phloem sap, the main ingesta of aphids, and in the mesophyll cells, has major implications for plant defense, through a feeding deterrent effect during stylet penetration, and deterrency (antixenosis) along with antibiosis during feeding.
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  • 30
    ISSN: 1573-1561
    Keywords: Spacing pheromones ; olfactometry ; aphids ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Olfactometry using an apterous individual of Rhopalosiphum padi (L.) showed an arresting effect by volatiles from a wheat seedling and a repellent effect by volatiles from a wheat seedling infested with aphids at a high population density (ca. 9 aphids/cm2). Four compounds, 6-methyl-5-hepten-2-one, (−)- and (+)-6-methyl-5-hepten-2-ol, and 2-tridecanone, were identified by GC-MS in air entrainments from the wheat seedlings with high aphid density but not from the wheat seedlings alone. The mixture of the four compounds in the natural proportion counteracted the attractivity of the volatiles from the intact uninfested wheat seedling. The likely role of these compounds in the spacing behavior of this aphid species, when present in high densities on wheat, is discussed.
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  • 31
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    Journal of chemical ecology 23 (1997), S. 543-551 
    ISSN: 1573-1561
    Keywords: Temperature ; photoperiod ; hydroxamic acids ; growth ; defense ; secondary metabolites ; wheat ; Gramineae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The effects of temperature and photoperiod on accumulation of hydroxamic acids (Hx) in wheat (Triticum aestivum L.) seedlings were evaluated under laboratory conditions. Hx concentrations were significantly higher at higher temperatures. No such clear trend was found for the photoperiod effect. The significant effect of temperature and photoperiod on growth rate of seedlings and the significant positive correlation between growth rate prior to analysis and levels of Hx, suggested that environmental effects on Hx accumulation were at least partially mediated through their effect on plant growth rate. After uncoupling the effect of environmental conditions from the effect of plant growth rate by statistical means the effect of temperature on Hx was no longer significant. Therefore, temperature effect was fully mediated by plant growth rate. Implications of the patterns found are discussed in issues of plant-defense general theories.
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  • 32
    ISSN: 1573-1561
    Keywords: allelopathy ; ferulic acid ; no-tillage ; prickly sida ; common ragweed ; weed control ; 2-methoxy-4-ethenylphenol ; carboxylic acid ; phenol ; morning glory ; Ipomoea lacunosa ; wheat ; Triticum aestivum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract This study was conducted to determine if well-known phytotoxic effects of plant residues on crop growth could also be responsible for observed reductions of certain weed species in no-till cropping systems. An aqueous extract of field-grown wheat (Triticum aestivum L.) reduced the germination and root length of pitted morning glory (Ipomoea lacunosa L.) and common ragweed (Ambrosia artemisiifolia L.). Phytotoxicity was increased by about 70% when bioassays with the wheat extract on morning glory and ragweed were conducted in the presence of light. Phytotoxic substances were extracted from wheat with 2 N NaOH. The hydrolyzed extract was fractionated by thin-layer chromatography (TLC). The compound isolated by TLC having the greatest inhibitory effects on morning glory germination was identified using mass spectrometry and determined to be ferulic acid (4-hydroxy-3-methoxycinnamic acid). Ferulic acid at 5 × 103 M inhibited the germination and root length of morning glory 23 and 82%, respectively, and prickly sida (Sida spinosa L.) with carpels 85 and 82%, respectively. Crabgrass (Digitaria sanguinalis L.) germination was inhibited 100%. Ferulic acid had no effect on ragweed or prickly sida without carpels. Morning glory root and shoot biomass were reduced 52 and 26%, respectively, when morning glory was grown in sand and watered with a 5 × 103 M solution of ferulic acid. Ferulic acid in the presence of prickly sida seed carpels was found to undergo decarboxylation, forming a styrene derivative, 2-methoxy-4-ethenylphenol. The more phytotoxic styrene compound was produced by a bacterium isolated from the carpels of prickly sida seed. The study showed that ferulic acid and other compounds may indeed play a role in reducing the growth of certain weeds in no-tillage cropping systems.
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  • 33
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    Journal of chemical ecology 9 (1983), S. 1001-1010 
    ISSN: 1573-1561
    Keywords: Rye ; wheat ; barley ; sorghum ; organic acids ; no-tillage ; crop residues
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract A variety of crops, cultivars, and accessions have been evaluated over the past six years for superior capability to suppress weed growth. The most successful of these approaches has been to grow cover crops of rye (Secale cereale), wheat (Triticum aestivum), sorghum (Sorghum bicolor), or barley (Hordeum vulgare) to a height of 40–50 cm, desiccate the crops by contact herbicides or freezing, and allow their residues to remain on the soil surface. Often, up to 95% control of important agroecosystem weed species was obtained for a 30- to 60-day period following desiccation of the cover crop. The plant residues on the soil surface exhibit numerous physical and chemical attributes that contribute to weed suppression. Physical aspects include shading and reduced soil temperatures which were similarly achieved using poplar (Populus) excelsior as a control mulch. Chemical aspects apparently include direct release of toxins, as well as production of phytotoxic microbial products. Numerous chemicals appear to work in concert or in an additive or synergistic manner to reduce weed germination and growth.
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  • 34
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    Mycopathologia 121 (1993), S. 115-121 
    ISSN: 1573-0832
    Keywords: Fusarium toxins ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Wheat for feed use (84 samples) was collected after harvest from 79 farms in a southwestern part of Germany (Baden-Wuerttemberg). The 1987 crop year was characterized by heavy rainfall in the summer months. The internal mycoflora of wheat samples was primarily fusaria, and storage fungi were rarely present. TheFusarium toxins, zearalenone (ZON), α- and β-zearalenol (α,β-ZOL), deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), nivalenol (NIV), T-2 Toxin (T-2), HT-2 toxin (HT-2) and diacetoxyscirpenol (DAS) were analysed by gas chromatography with mass selective detection (detection limit: 1–3 µg/kg). Each of the samples contained at least one of theFusarium toxins examined except DAS. DON, ZON, 3-AcDON, NIV, T-2, HT-2 and α-ZOL were detected in 96%, 80%, 59%, 26%, 26%, 7% and 5% of samples, with an average of 1632, 178, 7, 9, 82, 10 and 23 µg/kg, and a maximum of 20538, 8036, 18, 32, 249, 20 and 71 µg/kg, respectively. β-ZOL (12 µg/kg) was found in one sample with α-ZOL (71 µg/kg). One, two, three, four, five and sixFusarium toxins were detected in 6%, 27%, 37%, 23%, 4%, and 4% of total samples, respectively. The most frequent combination was that of ZON with DON and 3-AcDON, followed by the combinations ZON/DON and ZON/DON/3-AcDON/NIV in 22, 20, and 11% of total samples, respectively.
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  • 35
    ISSN: 1608-3040
    Keywords: antioxidant ; Endomyces magnusii ; apoptosis ; BHT ; DNA ; fragmentation ; DNA synthesis ; ontogenesis ; ROS ; plant ; protein synthesis ; superoxide ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It was found that production of superoxide (O2 – ·) is crucial for normal morphogenesis of etiolated wheat seedlings in the early stages of plant development. The development of etiolated wheat seedlings was shown to be accompanied with cyclic changes in the rate of O2 – · production both in the entire intact seedling and in its separated organs (leaf, coleoptile). First increase in the rate of O2 – · production was clearly observed in the period from two to four days of seedling development, then the rate of O2 – · production decreased to the initial level, and then it increased again for two days to a new maximum. An increase in O2 – · production in the period of the first four days of seedling development correlates with an increase in DNA and protein contents in the coleoptile. The second peak of increased rate of O2 – · production observed on the sixth or seventh day of seedling development coincides with a decrease in DNA and protein contents and apoptotic internucleosomal nuclear DNA fragmentation in the coleoptile. Incubation of seedlings in the presence of the antioxidant BHT (ionol) strongly affects their development but it does not influence the increase in DNA and protein contents for the initial four days of seedling life, and it slows down the subsequent age-dependent decrease in protein content and fully prevents the age-dependent decrease in DNA content in the coleoptile. A decrease in the O2 – · amount induced by BHT distorts the seedling development. BHT retards seedling growth, presumably by suppression of cell elongation, and it increases the life span of the coleoptile. It seems that O2 – · controls plant growth by cell elongation at the early stages of seedling development but later O2 – · controls (induces) apoptotic DNA fragmentation and protein disintegration.
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  • 36
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    Journal of chemical ecology 13 (1987), S. 1739-1747 
    ISSN: 1573-1561
    Keywords: Allelopathy ; parthenium ; Parthenium hysterophorus ; Compositae ; corn ; Zea mays ; ryegrass ; Lolium multiflorum ; wheat ; Triticum aestivum ; velvetleaf ; Abutilon theophrasti ; soybean ; Glycine max ; inhibition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Allelopathic effects of entire shoot extract, plant part extracts, and shoot residue of parthenium (Parthenium hysterophorus L.) on corn (Zea mays L.), ryegrass (Lolium multiflorum Lam.), wheat (Triticum aestivum L.), velvetleaf (Abutilon theophrasti Medik.), and soybean [Glycine max (L) Merr.] growth were examined. Parthenium shoot contained water-soluble materials that were toxic to root growth of velvetleaf and wheat. At 4% (w/ v) concentration, root growth of velvetleaf and wheat were reduced by 60 and 75%, respectively. The order of increasing sensitivity to parthenium was ryegrass, corn, wheat, and velvetleaf. There was a strong correlation between extract concentration and increased toxicity to test species. The toxicity of plant part extracts was also concentration dependent. At 1 and 2% (w/v), the inflorescence and leaves caused more root inhibition than stem extract. Parthenium shoot incorporated in soil at 1% (w/w) caused significantly more root inhibition of wheat than soybean, corn, and ryegrass. At 4% (w/w), root growth of all the test species was inhibited compared to the control. Toxicity of parthenium residue to wheat diminished with increasing periods of decomposition. Residue decomposed for four weeks was less toxic than the undecomposed residue.
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  • 37
    ISSN: 1573-1561
    Keywords: Hydroxamic acids ; phloem sap analysis ; aphid resistance ; cereals ; wheat ; Rhopalosiphum padi ; Homoptera ; Aphididae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Phloem sap of wheat seedlings differing in whole leaf hydroxamic acid (Hx) concentrations was collected by cutting stylets of feeding aphids. DIMBOA-glucoside was the only Hx-related product found. Concentration of DIMBOA-glucoside in phloem sap showed a tendency to be negatively correlated with aphid performance.
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