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981.
Strain-Specific Inhibition of nod Gene Induction in Bradyrhizobium japonicum by Flavonoid Compounds 总被引:7,自引:2,他引:5 下载免费PDF全文
Renee M. Kosslak Rita S. Joshi Benjamin A. Bowen Herbert E. Paaren Edward R. Appelbaum 《Applied microbiology》1990,56(5):1333-1341
A broad-host-range plasmid, pEA2-21, containing a Bradyrhizobium japonicum nodABC'-'lacZ translational fusion was used to identify strain-specific inhibitors of the genes required for soybean nodulation, the common nod genes. The responses of type strains of B. japonicum serogroups USDA 110, USDA 123, USDA 127, USDA 129, USDA 122, and USDA 138 to nod gene inhibitors were compared. Few compounds inhibited nod gene expression in B. japonicum USDA 110. In contrast, nod gene expression in strains belonging to several other serogroups was inhibited by most of the flavonoids tested. However, the application of two of these strain-specific compounds, chrysin and naringenin, had little effect on the pattern of competition between indigenous and inoculum strains of B. japonicum in greenhouse and field trials. Preliminary studies with radiolabeled chrysin and naringenin suggest that the different responses to nod gene inhibitors may be partly due to the degree to which plant flavonoids can be metabolized by each strain. 相似文献
982.
M. R. Lakshminarayana Syamasundar Joshi G. A. Nagana Gowda C. L. Khetrapal 《Journal of biosciences》1992,17(1):87-93
Abstract. The nuclear magnetic resonance imaging technique has been used to obtain images of different transverse and vertical
sections in groundnut and sunflower seeds. Separate images have been obtained for oil and water components in the seeds. The
spatial distribution of oil and water inside the seed has been obtained from the detailed analysis of the images. In the immature
groundnut seeds obtained commercially, complementary oil and water distributions have been observed. Attempts have been made
to explain these results. 相似文献
983.
N. V. Joshi 《Journal of genetics》1992,71(3):105-119
Competition between seeds within a fruit for parental resources is described using one-locus-two-allele models. While a “normal”
allele leads to an equitable distribution of resources between seeds (a situation which also corresponds to the parental optimum),
the “selfish” allele is assumed to cause the seed carrying it to usurp a higher proportion of the resources. The outcome of
competition between “selfish” alleles is also assumed to lead to an asymmetric distribution of resources, the “winner” being
chosen randomly. Conditions for the spread of an initially rare selfish allele and the optimal resource allocation corresponding
to the evolutionarily stable strategy, derived for species with n-seeded fruits, are in accordance with expectations based
on Hamilton’s inclusive fitness criteria. Competition between seeds is seen to be most intense when there are only two seeds,
and decreases with increasing number of seeds, suggesting that two-seeded fruits would be rarer than one-seeded or many-seeded
ones. Available data from a large number of plant species are consistent with this prediction of the model.
Based on a talk given at the Haldane Centenary Symposium held on 6 November 1992 at Ahmedabad as part of the 58th Annual Meeting
of the Indian Academy of Sciences. 相似文献
984.
U Jain P K Desai M T Patel D K Joshi P Kaliraj 《Indian journal of experimental biology》1990,28(12):1118-1123
Entamoeba histolytica soluble crude antigen was fractionated by gel filtration on Sephacryl S-300 into four fractions, viz. F1(669 kDa); F2(51.2 kDa); F3(25.1 kDa) and F4(10.5 kDa). F1 fraction was observed to be more sensitive and specific for the detection of antibody in amoebiasis than the crude and other fractions of purified antigens employing IHAT and ELISA. ELISA was found to be better than IHAT since it could detect antibody in the sera (3/6) of asymptomatic cyst passers. The cross reaction of crude antigen with toxocariasis (1/4) and toxoplasmosis (2/5) sera were associated with F4 fraction. F3 and F4 were having low molecular weight and were not sensitive in detection of antibody in amoebiasis. Biochemical characterization revealed glycoprotein nature of the specific (F1) antigen fraction. 相似文献
985.
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987.
Growth and development of the oestrogen-primed oviduct of immature chicks in terms of weight, length, total protein, total RNA, total DNA and total phospholipids are markedly arrested on deprivation of vitamin A; supplementation with retinyl acetate reversed the effect of the deficiency almost fully, whereas retinoic acid was only partly effective. 相似文献
988.
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990.
A quartz-flow-cell system for irradiation of large volumes of Escherichia coli cultures with ultraviolet light is described. With this system kilogram quantities of irradiated cells can be obtained for biochemical studies. Changes in respiration and in specific activities of superoxide dismutase and catalase, after an ultraviolet treatment that reduced viability of culture samples to 0.2%, were in good agreement with those for cultures irradiated (52J/m2) by a conventional small-scale method to produce the same reduction in viability. 相似文献