title: NaCl-induced physiological and biochemical changes in two cyanobacteria Nostoc muscorum and Phormidium foveolarum acclimatized to different photosynthetically active radiation.
abstract: The present study is aimed at investigating physiological and biochemical behavior of two cyanobacteria Nostoc muscorum and Phormidium foveolarum acclimatized to different levels (sub-optimum; 25 ± 0.5, optimum; 75 ± 2.5 and supra-optimum; 225 ± 3.5 μmol photons m(-2) s(-1)) of photosynthetic active radiation (PAR), and subsequently treated with two doses (30 and 90 mM) of NaCl. PAR influences growth in tested cyanobacteria being maximum in supra-optimum PAR acclimatized cells. NaCl-induced maximum percent decline in growth was observed in sub-optimum PAR acclimatized cells, which was in consonance with a decrease in chlorophyll content. Sub-optimum PAR acclimatization stimulated phycocyanin content in control cells, whereas maximum carotenoids content was observed in supra-optimum PAR acclimatized cells. Photosystem II photochemistry viz. Fv/F0, Fv/Fm, Ψ0, ϕE0, PIABS, ABS/RC, TR0/RC, ET0/RC and DI0/RC was also influenced by PAR and NaCl. Maximum percent rise in superoxide radical (SOR), hydrogen peroxide (H2O2) and lipid peroxidation was observed in sub-optimum PAR acclimatized cells exposed to NaCl, which could be correlated with lower values of enzymatic (superoxide dismutase, catalase, peroxidase and glutathione-S-transferase) and non-enzymatic (NP-SH and cysteine) antioxidants. In supra-optimum PAR acclimatized cells level of oxidative stress markers was in parallel with enhanced antioxidants. The results suggest that PAR significantly changes physiological and biochemical responses of studied cyanobacteria under NaCl stress. Besides this, this study also shows that P. foveolarum is more tolerant than N. muscorum under test conditions.
authors: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: jitendradhuria@gmail.com.
authors: Jitendra
authors: J
authors: Kumar
authors: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: vijaypratap.au@gmail.com.
authors: Vijay Pratap
authors: VP
authors: Singh
authors: Ranjan Plant Physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India. Electronic address: profsmprasad@gmail.com.
authors: Sheo Mohan
authors: SM
authors: Prasad
mesh_terms: D000064:Acclimatization / Q000187:drug effects / Q000502:physiology*; D000975:Antioxidants / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D000458:Cyanobacteria / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D003545:Cysteine / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects / Q000502:physiology; D050502:Nostoc muscorum / Q000737:chemistry / Q000187:drug effects / Q000502:physiology; D018384:Oxidative Stress; D010788:Photosynthesis / Q000187:drug effects* / Q000502:physiology; D010798:Phycocyanin / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D054712:Salinity; D012965:Sodium Chloride / Q000494:pharmacology*; D013045:Species Specificity; D013472:Sunlight
chemical_list: D000975:Antioxidants; D004798:Enzymes; D017382:Reactive Oxygen Species; D010798:Phycocyanin; D002734:Chlorophyll; D002338:Carotenoids; D012965:Sodium Chloride; D003545:Cysteine
keywords: Antioxidant enzymes; Cyanobacteria; Oxidative stress markers; Photosynthesis; Photosynthetically active radiation; Salt