INTERACTION OF PHOTOSYNTHESIS AND NITROGEN METABOLISM IN ACID STRESS TOLERANCE OF NOSTOC sp.
| dc.contributor.advisor | Dhar Wattal Dolly | |
| dc.contributor.author | HIMANI PRIYA | |
| dc.date.accessioned | 2019-09-12T05:32:37Z | |
| dc.date.available | 2019-09-12T05:32:37Z | |
| dc.date.issued | 2019 | |
| dc.description | T-10073 | en_US |
| dc.description.abstract | Low pH tolerant Nostoc strains grown under control (pH 7.0) and low pH (pH 4.5) conditions, and fresh water strain Nostoc punctiforme, grown in medium having pH 7.0, in absence or presence of nitrogen or carbon supplementation, were used to study growth and physiological parameters during exponential phase of growth. Comparative study amongst selected Nostoc strains under control pH (7.0) and low pH (4.5) medium indicated a significant and variable influence of nitrogen or carbon supplementation for specific traits. The chlorophyll content was not influenced by supplementation, while, total soluble proteins exhibited a variable pattern with N supplementation, and was reduced with carbon supplementation. Extracellular ammonia release was higher without supplementation as compared to supplemented medium. Intracellular sucrose remained more or less similar under three conditions at pH 7.0, while under low pH, supplementation showed an enhancement. Supplementation of medium increased oxygen evolution rate, and Fv/Fm ratio without or with N indicated varied response, whereas Fv/Fm ratio was reduced with carbon supplementation. Carbon supplementation in the medium enhanced nitrogenase activity several folds and nitrate reductase activity enhanced significantly with nitrogen supplementation as compared to un-supplemented medium under pH 7.0 or 4.5. Carbon supplementation in the medium did not have much impact on nitrate reductase activity. Nitrite reductase activity enhanced with N or C supplementation, while the activity of glutamine synthetase depicted differential response under two pH growing conditions. Proline content and lipid peroxidation was higher in cultures in absence of N or C supplementation as compared to the supplemented medium, whereas glycerol content was increased with nitrogen and decreased with C supplementation. Glycine betaine remained more or less similar under un-supplemented or supplemented medium of pH 7.0 or pH 4.5. Activities of superoxide dismutase and catalase were higher under unsupplemented medium as compared to cultures grown in medium having N or C supplementation. Catalase and ascorbate peroxidase activity also showed reduction when the medium was supplemented with N or C as compared to un-supplemented 221 medium. Statistical analysis indicated that the interactive effect was significant for most of the selected parameters. Calculation for Principal Components Analysis was done and the total % variance contributed by first four Principal Components accounted for 96 %. Principal Components (PC1 and PC2) contributed positively under some situations and negatively under others. Combined analyses of PC1-PC4 confirmed the individual analyses and clustering treatments in the same trend. Pearson correlation coefficients analyses based on p value showed different levels of correlation amongst selected parameters studied under two cultural conditions and cluster analysis indicated trait variation amongst Nostoc cultures. Gene expression study for nifH and rbcL gave variable results by low pH tolerant strains under two conditions of growing medium (pH 7.0; pH 4.5). Studies conducted clearly indicated complexity of abiotic stress mechanism involving morpho-physiological and genetic attributes in cyanobacteria. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810127441 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | DIVISION OF Microbiology ICAR- INDIAN AGRICULTURAL RESEARCH INSTITUTE NEW DELHI | en_US |
| dc.sub | Microbiology | en_US |
| dc.subject | null | en_US |
| dc.theme | INTERACTION OF PHOTOSYNTHESIS AND NITROGEN METABOLISM IN ACID STRESS TOLERANCE OF NOSTOC sp. | en_US |
| dc.these.type | Ph.D | en_US |
| dc.title | INTERACTION OF PHOTOSYNTHESIS AND NITROGEN METABOLISM IN ACID STRESS TOLERANCE OF NOSTOC sp. | en_US |
| dc.type | Thesis | en_US |