Growth, photosynthesis, active oxygen species and antioxidants responses of paddy field cyanobacterium Plectonema boryanum to endosulfan stress

The Journal of General and Applied Microbiology

Mohd. Zeeshan¹  Deelip Kumar¹  Sheo Mohan Prasad¹ 

[1] Ranjan Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad

关键词: active oxygen species;    antioxidants;    14C-fixation;    endosulfan;    lipid peroxidation;    membrane leakage;    photosynthetic electron transport chain;    Plectonema boryanum;   

DOI  :  10.2323/jgam.51.115

学科分类：微生物学和免疫学

来源: Applied Microbiology, Molecular and Cellulrar Biosciences Research Foundation

【 摘 要 】

The Present paper deals with the insecticide endosulfan (5, 10 and 20 μg/ml)-induced changes in physiological and biochemical parameters related to photosynthesis and defense systems in paddy field cyanobacterium Plectonema boryanum grown under laboratory conditions. Growth and photosynthetic pigments, i.e., chlorophyll a, carotenoids and phycocyanin, were adversely affected by endosulfan treatment and the inhibition was found to be dose dependent. The toxic effect of endosulfan was more pronounced on phycocyanin; however, a considerable reduction in chlorophyll a and carotenoids was also noticed. 14C-fixation appeared to be more sensitive to insecticide than whole cell oxygen evolution. Spheroplasts treated with endosulfan exhibited a severe effect on PSII activity which was mainly due to blocking of the electron flow at the water oxidation side. In contrast to this, similar doses of endosulfan caused the least effect on PSI activity (DCPIP/ASC→MV). Furthermore, endosulfan with increasing doses accelerated the formation of active oxygen species, i.e., O2− and H2O2, in cells progressively, whereby an enhanced peroxidation of lipid and leakage of cell membrane were noticed. As a consequence of active oxygen species (AOS) generation in endosulfan-treated cells, the activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) was enhanced considerably. Besides the accelerated action of enzymatic defense systems, chemical antioxidant ascorbate showed a decreasing trend with the rising concentration of endosulfan (5, 10 and 20 μg/ml).

【 授权许可】

Unknown