Rai, L.C.Rai, TushitaKumar, Rajesh2021-12-092021-12-092021Cyanobacteriahttps://krishikosh.egranth.ac.in/handle/1/5810178915The presence of prevalent nitrogen-fixing, photosynthetic cyanobacteria is a common inhabitant of the tropical rice fields. Their early emergence on earth and survival in extreme conditions through biotic and a-biotic stresses allied with their plant-like habits and phylogenetic relationship with plant chloroplasts makes them the most appropriate model system for studying plant response to different biotic along with abiotic environmental stresses. In terms of the magnitude of damage and global distribution, cold stress emerges as the principal determinant of crop productivity among all the stress. Acclimation of cyanobacteria in cold stress involves induction of the expression of several families of genes. In response to low temperature, several biological and physicochemical changes occur in cellular physiology so as (i) decrease in membrane fluidity, (ii) stabilization of secondary structures of nucleic acids leading to reduced efficiency of mRNA translation and transcription, (iii) inefficient folding of some proteins, and (iv) hampered ribosome function. The present study shows the importance of Cold-shock response and adaptation towards cold stress, which has been studied extensively in Anabaena PCC 7120. Many RNA Binding Proteins have been produced to counteract these harmful effects of temperature downshift. Cold stress enhances the level of RNA binding protein (rbp) in the cell and acts as an essential player in RNA metabolism5. RNA-binding proteins play a significant role in regulating transcription and termination and generally accumulate after a fall in temperature. The following study intended to determine the effect of cold stress on the expression of RNA-binding proteins by using In-silico and wet lab approaches. The transcript levels of genes All 4377 were monitored in Anabaena sp. PCC 7120 cultures. Steady-state transcript levels of gene all 4377 increased transiently in response to a temperature shift from 30 to 20‡C under both the circumstances of nitrogen regimes. Recombinant plasmid transformed in E. coli showed better survival under low temperatures. Therefore, this study concluded that low temperature modulates the stress-responsive regulation of RNA-binding proteins in cyanobacteria, providing a coherent mechanism to integrate environmental and molecular signals.EnglishThesis