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Ramesh Chand Manoj Kumar Chanda Kushwaha Kavita Shah Arun K. Joshi 《Current microbiology》2014,69(2):202-211
Eighteen barley isolates of Bipolaris sorokiniana belonging to wild and clonal type of black, mixed and white subpopulations were quantitatively assayed for their melanin content and aggressiveness with respect to production of some of the extracellular enzymes such as cellulase, pectinase, amylase and protease. Cellulase and pectinase constituted major portion of the enzymes recovered from the black, mixed and white isolates. Enzyme production and aggressiveness were relatively higher in melanin devoid or low melanin isolates. The melanin deficient isolates were also differentiated from black and mixed isolates on the basis of variation in internal transcribed spacer region of the ribosomal DNA. Higher enzyme productions positively correlated with area under disease progress curve (AUDPC) and lesion development. Melanin content was negatively correlated with extracellular enzymes and aggressiveness of the isolates. Based on melanin content, lesion size, AUDPC and extracellular enzymes, the isolates were grouped in two major clusters (I and II) with further division of cluster II into two sub-clusters (II-A and II-B). The results appears to indicate a possible role of melanin in release of extracellular enzymes and hence in evolution and selection of aggressive isolates of B. sorokiniana in barley. 相似文献
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Axillary buds of mulberry (Morus indica L) were encapsulated in alginate and agar to produce individual beads. The beads could be stored at 4°C for 45 days without loss of viability. Amongst the encapsulating agents tested, sodium alginate was found to be a better matrix. Encapsulated buds regenerated complete plantlets on an appropriate medium. This technique would provide an easy and novel propagation system for the elite as well as difficult-to-root species of mulberry.Abbreviations BAP
benzylaminopurine
- MS
Murashige and Skoog (1962). 相似文献
5.
Biochemical characteristics of bi-resistant mutants (resistant to ethambutol plus streptomycin or isoniazid plus streptomycin)
of mycobacteria isolated by replica plating fromMycobacterium smegmatis ATCC were compared with those of the drug-susceptible strains. Reduced incorporation of [14C]uracil, [3H]lysine and [14C]acetate into RNA, protein and phospholipids respectively was seen in the resistant mutants. Total phosphorlipids were enhanced
in ethambutol plus streptomycin resistant mutant and decreased in isoniazid plus streptomycin resistant mutant. There were
similar changes in levels of individual phospholipids. The resistant mutants revealed an accumulation of phospholipids in
the cell wall, and a marked decrease of phospholipids in the cell membrane in comparison to the susceptible strain. Several
qualitative alterations in the polypeptide profile (with respect to number and molecular weight) of the crude protein extract
and of different subcellular compartments were seen in the resistant mutants. 相似文献
6.
The effect ofl-ascorbic acid on the biosynthesis of aflatoxin inAspergillus parasiticus was studied. Ascorbic acid at lower concentrations did not inhibit the growth of fungus but markedly induced aflatoxin biosynthesis. At a concentration of 1000 ppm of ascorbic acid, 4.8-fold higher levels of aflatoxin were detected. Copper did not enhance the induction of toxin synthesis by ascorbic acid when added to the growth medium. Ascorbic acid at 1000 ppm was also found to induce aflatoxin synthesis in resting mycelia. Chloroform (1% vol/vol) was found to induce aflatoxin synthesis under similar conditions. Ascorbic acid in the presence of ferrous ion can cause lipid peroxidation, which in turn is responsible for the induction of aflatoxin synthesis. During the induction of aflatoxin synthesis by ascorbic acid, the uptake of carbon source (acetate) was not affected. This observation suggests that on ascorbic acid treatment a precursor or an intermediate of aflatoxin biosynthesis is synthesized in vivo and is responsible for the higher levels of toxin without increasing the uptake of acetate. 相似文献
7.
Propagation of banana through encapsulated shoot tips 总被引:4,自引:0,他引:4
Plants were regenerated from encapsulated shoot tips of banana. Shoot tips (ca 4 mm) isolated from multiple shoot cultures of banana cv. Basrai were encapsulated in 3% sodium alginate containing different gel matrices. The encapsulated shoot tips regenerated in vitro on different substrates. Use of White's medium resulted in 100% conversion of encapsulated shoot tips into plantlets. The plantlets were successfully established in soil.Abbreviations BA
Benzylaminopurine
- NAA
Naphthalene acetic acid
- DMSO
Dimethyl sulphoxide 相似文献
8.
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Identification and some properties of a unique DNA polymerase from cells infected with human B-lymphotropic virus. 总被引:1,自引:0,他引:1 下载免费PDF全文
A new DNA polymerase and DNase activity were identified from cells infected with human B-lymphotropic herpesvirus (HBLV). DNA polymerase associated with HBLV infection was similar in its sensitivity to inhibition by ppi analogs as other herpesvirus-specific DNA polymerases but was dissimilar in its inhibition by certain nucleoside triphosphates. 相似文献
10.
Analysis of γ-Aminobutyric AcidA Receptor Subunits in the Mouse Cochlea by Means of the Polymerase Chain Reaction 总被引:1,自引:0,他引:1
Dennis G. Drescher Glenn E. Green Khalid M. Khan† Kavita Hajela Kirk W. Beisel Barbara J. Morley Anil K. Gupta 《Journal of neurochemistry》1993,61(3):1167-1170
Abstract: Unlike 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), which produces consistent decreases in levels of striatal dopamine (DA) with considerably smaller and more variable effects on mouse brain levels of serotonin (5-HT) and norepinephrine (NE), a novel amine-substituted MPTP analogue, 1-methyl-4-(2'-aminophenyl)-1,2,3,6-tetrahydropyridine (2'-NH2 -MPTP), administered in a standard mouse dosing paradigm for MPTP (20 mg/kg X 4) did not affect striatal DA but led to marked reductions (60–70%) in levels of 5-HT, 5-hydroxyindoleacetic acid (5-HIAA), and NE measured in frontal cortex and hippocampus 1 week after treatment. Another 2'-substituted MPTP analogue, 1-methyl-4-(2'-methylphenyl)-1,2,3,6-tetrahydropyridine, affected cortical and hippocampal 5-HT, 5-HIAA, and NE only minimally, while markedly reducing the DA content in striatum (90%), thus indicating that the substituent (-NH2 versus -CH3 ) at the 2'position is important for the differential effects of these MPTP analogues. In a replication study with a 3-week end point, hippocampal and cortical 5-HT, 5-HIAA, and NE levels remained depressed with no indication of recovery. These results suggest that 2'-NH2 -MPTP may be a novel, regionally selective neurotoxin for serotonergic and norad-renergic nerve terminals. 相似文献