Record Details

Salt induced alterations in the Physiological, Biochemical and Proteomic profile of the symbiotic cyanobacterium Anabaena azollae

KrishiKosh

View Archive Info
 
 
Field Value
 
Title Salt induced alterations in the Physiological, Biochemical and Proteomic profile of the symbiotic cyanobacterium Anabaena azollae
 
Creator Yadav, Ravindra Kr.
 
Contributor W. Ramteke, Pramod
 
Subject planting, pomegranates, regeneration, diseases, genetic processes, bacteria, genes, biological phenomena, vegetative propagation, concentrates
pteridophyte Azolla, biofertilizer, DNA, cyanobiont
 
Description Thesis entitled“Salt induced alterations in the Physiological, Biochemical and Proteomic profile of the symbiotic cyanobacterium Anabaena azollae” submitted in partial fulfillment of requirement for the award of the degree of Doctor of Philosophy in Microbiology by Ravindra K. Yadav.
The aquatic nitrogen fixing pteridophyte Azolla is an excellent biofertilizer for rice paddy fields owing to its ability fix to atmospheric nitrogen. However, wider exploitation of Azolla is hampered due to increasing soil salinity. Understanding the physiological response of the cyanobiont to salinity is therefore important to unravel the salinity tolerance mechanism operating in this system. This will further pave way for the intervention of advanced molecular biological tools to work out the mechanisms operating under salinity stress conditions in the cyanobionts. Therefore in the present study the physiological and biochemical response of freshly separated cyanobionts from two different species of Azolla viz. A. microphylla and A. caroliniana exposed to salinity was studied. Freshly separated cyanobionts of Azolla microphylla and Azolla caroliniana plants exposed to salinity showed decline in the cellular constituents such as chlorophyll (23.1 and 38.9%) and protein (12.9 and 19.3%). However, an increase in the carotenoid and sugar content was observed. Exposure to salinity stress reduced the heterocyst frequency (35.4 and 57.2%) and nitrogenase activity (37.7 and 46.3%) of the cyanobionts. Increase in the activity of antioxidant enzymes such as super oxide dismutase (50.6 and 11.5%), ascorbate peroxidase (63.7 and 57.9%), catalase (94.2 and 22.5%) as well as non-enzymatic antioxidant proline (18.8 and 13.3 %) was also observed in response to salinity. The cyanobionts exhibited significant increase in the intracellular Na+ level and reduced intracellular K+/Na+ and Ca2+/Na+ ratio in response to salinity. The results demonstrated the adverse impact of salinity on the freshly separated cyanobionts as similar to free living cyanobacteria. Salinity stress response mechanisms in the freshly isolated cyanobionts Anabaena azollae was studied at the
proteome level using two dimensional gel electrophoresis (2DE) followed by MALDI-TOF-MS/MS analysis. Thirty five (35) protein spots were significantly altered due to exposure to salinity. Among them, thirteen (13) spots were down regulated and twenty two (22) spots were up regulated. A total of twenty (20) new or hypothetical proteins have also been identified in the present study. These proteins are associated with a variety of functions including energy metabolism protein synthesis and folding, DNA damage and repair, stress and defense. The study might help in understanding the biological processes and stress proteins involved in salinity stress adaptation. Results show that the cyanobiont resorts to elaborate changes in the protein synthesis and cell signaling to survive under salinity induced stress conditions. These results may be helpful in the critical evaluation of salinity tolerance mechanism of the cyanobiont and its interaction with the host.
 
Date 2016-12-15T10:21:56Z
2016-12-15T10:21:56Z
2016
 
Type Thesis
 
Identifier http://krishikosh.egranth.ac.in/handle/1/90246
 
Language en
 
Format application/pdf
 
Publisher Sam Higginbottom Institute of Agriculture, Technology & Sciences (SHIATS)