A Comparative study on proteomic and biochemical alterations in the cyanobacterium Anabaena sp. PCC 7120 under short term exposure of abiotic stresses: Pesticide, salinity, heavy metal and UV- B

D Leshan Wannigama, Chhavi Agrawal and L.C. Rai

: Agrotechnol

Abstract:

Cyanobacteria are significant contributors to global photosynthetic productivity, thus making it relevant to study how the different abiotic stresses can alter their cellular activities. Here, changes in phycocyanin pigment composition, antioxidants enzyme activity, peroxidase production, NADPH, thiol content and SDS-PAGE protein profile were examined during a short- term exposure of the cyanobacterium Anabaena sp. strain PCC7120 to Salinity, Butachlor, Cadmium and UV-B. Of these stress conditions, a maximum inhibiton of phycocyanin content was observed for UV-B irradiation followed by butachlor, salt and Cd as compared to control. The total thiol content in the organism is raise slightly over the basal level, to overcome stress imposed by salt and cadmium. However, in UV-B and butachlor only showed the 0.6 and 0.95 fold significant decline in thiol level in comparison to control. Interestingly, in all cases, NADPH\NADH level is significantly decrease below the basal level. Lipid Peroxidation was found to be increase significantly in all stresses, while a SOD and catalase registered a maximum increase in cadmium and UV-B. A peroxidase production found to be highest in response to butachlor. Further, SDS-PAGE analyses of the total protein profile revealed the appearance of several differentially expressed protein bands in all the four stress. In addition, several up and down regulated proteins, newer protein bands appeared in treated cultures when compared to the control. However, biochemical and proteomic attributes suggests that, to overcome the abiotic stress, organisms generally might have defense mechanisms that prevent interaction with the stress factors and that counteract the stress-induced damages. Keywords: Abiotic stress, Cyanobacteria, Antioxidant enzymes, SDS-PAGE.

Biography :

Dhammika Leshan Wannigama is the final year student of Bsc (Hons) Industrial Microbiology at Center for Advanced studies in Botany, Banaras Hindu University, Varanasi-221005, India. He has published three international research publications, two seminar publications and including final year dissertation project related to molecular biology, under supervision of Professor L.C Rai. In year 2011 he has won the summer research training fellow ship in Tropical Microbiology, Department of Microbiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand