ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

1

Electronic Resource

Expression of a cysteine proteinase inhibitor (oryzacystatin-I) in transgenic tobacco plants (1993)

Masoud, Sameer A. ; Johnson, Lowell B. ; White, Frank F. ; [et al.]

Springer

Plant molecular biology 21 (1993), S. 655-663

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ISSN: 1573-5028

Keywords: Agrobacterium tumefaciens ; cystatin ; plant transformation ; protease inhibitor

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Expression of cysteine proteinase inhibitors (cystatins) in tobacco or other plants has the potential for improving resistance against pathogens and insects that possess cysteine proteinases. A chimeric gene containing a cDNA clone of rice cystatin (oryzacystatin-I; OC-I), the cauliflower mosaic virus 35S promoter, and the nopaline synthase 3′ region was introduced into tobacco plants by Agrobacterium tumefaciens. The presence of the chimeric gene in transgenic plants was detected by a polymerase chain reaction-amplified assay, and transcriptional activity was shown by RNA blot analysis. Heated extracts from transgenic tobacco plants, as well as from progeny which were obtained by selfing a primary transformant, contained protein bands that corresponded in molecular mass to OC-I and reacted with antibodies raised against rOC, a recombinant OC-I protein produced by Escherichia coli. Similar bands were absent in extracts from untransformed control plants. OC-I levels reached 0.5% and 0.6% of the total soluble proteins in leaves and roots, respectively, of some progeny. On a fresh weight basis, the OC-I content was higher in leaves (50 μg/g) than in roots (30 μg/g). OC-I was partially purified from protein extracts of rice seeds and from transgenic tobacco leaves by affinity to anti-rOC antibodies. OC-I from both sources was active against papain.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00014548

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2

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Heteroplasmy of chloroplast DNA in Medicago (1989)

Johnson, Lowell B. ; Palmer, Jeffrey D.

Springer

Plant molecular biology 12 (1989), S. 3-11

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ISSN: 1573-5028

Keywords: alfalfa ; chloroplast DNA ; chloroplast DNA heterogeneity ; heteroplasmy ; Medicago ; restriction mapping

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Two chloroplast DNA (cpDNA) regions exhibiting a high frequency of intra- or inter-species variation were identified in 12 accessions of the genus Medicago. Restriction maps of both regions were prepared for alfalfa, and the probable nature of the events causing the DNA differences was identified. Specific DNA fragments were then cloned for use in identification of variants in each region. Two each of M. sativa ssp. varia and ssp. caerulea and one of six M. sativa ssp. sativa single plants examined possessed cpDNA heterogeneity as identified by screening extracts for fragments generated by the presence and absence of a specific Xba I restriction site. Three plants of M. sativa ssp. sativa, two of each of sspp. varia and caerulea, and three M. scutellata were also examined for single-plant cpDNA heterogeneity at a hypervariable region where differences resulted from small insertion-deletion events. A single M. scutellata plant with mixed cpDNAs was identified. Sorting out was seen when one spp. sativa plant with mixed plastid types identifiable by the Xba I restriction site difference was vegetatively propagated. This indicated that the initial stock plant was heteroplastidic. Controlled crosses will be required in order to test whether heteroplasmy results from chloroplast transmission in the pollen and to examine the dynamic of sorting out. However, heteroplasmy is apparently not a rare situation in Medicago.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00017442

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3

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Insect resistance of transgenic tobacco expressing an insect chitinase gene (1998)

Ding, Xiongfei ; Gopalakrishnan, Bhuvana ; Johnson, Lowell B. ; [et al.]

Springer

Transgenic research 7 (1998), S. 77-84

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ISSN: 1573-9368

Keywords: Bacillus thuringiensis toxin ; Heliothis virescens ; Manduca sexta ; Nicotiana tabacum ; tobacco budworm ; tobacco hornworm ; chitinase

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Chitinase expression in the insect gut normally occurs only during moulting, where the chitin of the peritrophic membrane is presumably degraded. Thus, insects feeding on plants that constitutively express an insect chitinase gene might be adversely affected, owing to an inappropriately timed exposure to chitinase. This hypothesis was tested by introducing a cDNA encoding a tobacco hornworm (Manduca sexta) chitinase (EC 3.2.1.14) into tobacco via Agrobacterium tumefaciens-mediated transformation. A truncated but enzymatically active chitinase was present in plants expressing the gene. Segregating progeny of high-expressing plants were compared for their ability to support growth of tobacco budworm (Heliothis virescens) larvae and for feeding damage. Both parameters were significantly reduced when budworms fed on transgenic tobacco plants expressing high levels of the chitinase gene. In contrast, hornworm larvae showed no significant growth reduction when fed on the chitinase-expressing transgenics. However, both budworm and hornworm larvae, when fed on chitinase-expressing transgenic plants coated with sublethal concentrations of a Bacillus thuringiensis toxin, were significantly stunted relative to larvae fed on toxin-treated non-transgenic controls. Foliar damage was also reduced. Plants expressing an insect chitinase gene may have agronomic potential for insect control

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1023/A:1008820507262

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4

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Karyotypic and chloroplast genomic diversity inMedicago sect.Lupularia (Leguminosae) (1989)

Schlarbaum, S. E. ; Rose, R. J. ; Small, E. ; [et al.]

Springer

Plant systematics and evolution 166 (1989), S. 69-78

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ISSN: 1615-6110

Keywords: Angiosperms ; Leguminosae ; Medicago lupulina ; M. secundiflora ; Chromosomes ; karyotypes ; chloroplast DNA evolution ; phylogeny

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Studies were made on the chromosome complements and chloroplast genomes ofMedicago lupulina andM. secundiflora, which comprise sectionLupularia ofMedicago. Both types of analyses indicated more substantial differences between these species than suggested by external morphology.Medicago lupulina has a relatively asymmetrical karyotype in terms of centromeric position and relative length. The karyotype ofM. secundiflora is comparatively more asymmetrical in centromeric position and reduced in absolute size but exhibits greater symmetry in relative length. The restriction endonuclease fragmentation patterns of the chloropiast DNA of these two species (with Bam HI, Eco RI, Bgl II, and Xho I) show little similarity, with only 17% of the fragments matching in size. The lack of interspecific congruence among data of morphology, karyology and cpDNA inLupularia is contrary to consistency exhibited among these data inMedicago subsect.Intertextae.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00937876

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5

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Karyotypic evolution, morphological variability and phylogeny inMedicago sect.Intertextae (1984)

Schlarbaum, S. E. ; Small, Ernest ; Johnson, Lowell B.

Springer

Plant systematics and evolution 145 (1984), S. 203-222

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ISSN: 1615-6110

Keywords: Fabaceae ; Leguminosae ; Medicago ciliaris ; Medicago intertexta ; Medicago muricoleptis ; Medicago granadensis ; Evolution ; chromosomes ; Pleistocene glaciations

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Abstract Karyotype and external morphological analyses were conducted onMedicago ciliaris, M. intertexta, M. muricoleptis andM. granadensis which comprise theIntertextae section of the genusMedicago. All species were found to have 2n = 16 chromosomes (= 2 ×), including one pair of satellite chromosomes in each respective complement. Karyotypic evolution in theIntertextae involves changes in absolute chromosome size and in centromeric and relative size symmetry. Numerical taxonomic analyses were conducted independently on 17 karyotypic features and on 16 features of external morphology. The results of the two sets of analyses proved comparable, withM. ciliaris andM. intertexta forming a fairly close pair, and the remaining two species appearing to have more distant relationships to each other and to the first pair. These observations are consistent with the infertility relationships and chorologies of the species. It is suggested thatM. muricoleptis andM. granadensis are derived from theM. ciliaris/intertexta species complex withM. granadensis arising fromM. muricoleptis, or these two species independently evolving from a common species complex. Chromosomal and numerical analyses suggest thatM. ciliaris is the most primitive andM. granadensis the most derived species of theIntertextae.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00983949

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6

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Restriction endonuclease studies on the chloroplast and mitochondrial DNAs of alfalfa (Medicago sativa L.) protoclones (1986)

Rose, R. J. ; Johnson, Lowell B. ; Kemble, R. J.

Springer

Plant molecular biology 6 (1986), S. 331-338

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ISSN: 1573-5028

Keywords: alfalfa ; chloroplast DNA ; Medicago sativa L. ; mitochondrial DNA ; protoclone ; protoplast

Source: Springer Online Journal Archives 1860-2000

Topics: Biology

Notes: Summary Alfalfa protoclones were regenerated from the mesophyll protoplasts of two cloned source plants (parents), RS-K1 and RS-K2, initiated from Regen S seed. Because of the high frequency of karyotypic upset previously observed in these plants, chloroplast DNAs (cpDNA) from 23 protoclones and mitochondrial DNAs (mtDNA) from 20 protoclones were examined by restriction endonuclease analysis in order to assess recombination in their cytoplasmic genomes. Seven and four endonucleases were separately used for cpDNA and mtDNA analysis, respectively. Data were consistent with no, or a low frequency of, major sequence rearrangements in either the chloroplast or the mitochondrial genomes as a result of protocloning. However, two types of cpDNA were detected in the 23 protoclones, with only one protoclone possessing the cpDNA type of the cloned parental populations sampled. Possible explanations include a preferential selection during protocloning for one of two parental cpDNA types, an in planta sorting out of cpDNA types in the parental material or both.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1007/BF00034940

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