Ranjan Plant physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
Ranjan Plant physiology and Biochemistry Laboratory, Department of Botany, University of Allahabad, Allahabad 211002, India.
Ecotoxicol Environ Saf. 2018 Aug 15;157:369-379. doi: 10.1016/j.ecoenv.2018.03.056. Epub 2018 Apr 6.
The present study deals with impact of varied doses of arsenite (As; 50, 100 and 150 µM) and arsenate (As; 50, 100 and 150 mM) on growth, photosynthetic pigments, photochemistry of photosystem II, oxidative biomarkers, (O¯, HO and MDA equivalents contents) and activity of antioxidant enzymes in diazotrophic cyanobacterium Nostoc muscorum after 48 and 96 h of the treatments. The reduction in growth, pigment contents (Chl a, Phy and Car) and PS II photochemistry was found to increase with enhanced accumulation of test metal in cells, and the damaging effect on photosynthetic pigments showed the order (Phy > chl a> Car). The negative effect on PS II photochemistry was due to significant decrease in the value of JIP kinetics ϕP, F/F, ϕE,Ψ and PI except F/F and significant rise in values of energy flux parameters such as ABS/RC, TR/RC, ET/RC and DI/RC. Both the species of arsenic caused significant rise in oxidative biomarkers as evident by in vitro and in vivo analysis of (O¯, HO and MDA equivalents contents) despite of appreciable rise in the activity antioxidative enzymes such as SOD, POD, CAT and GST. The study concludes that in among both forms of arsenic, arsenite effect was more dominant on growth, photosynthetic pigments; oxidative stress biomarkers as evident by weak induction of anti-oxidative defense system to overcome the stress as compared to arsenate.
本研究探讨了不同剂量亚砷酸盐（As；50、100 和 150µM）和砷酸盐（As；50、100 和 150mM）对固氮蓝藻念珠藻生长、光合色素、光系统 II 光化学、氧化生物标志物（O¯、HO 和 MDA 当量含量）和抗氧化酶活性的影响。处理 48 和 96 小时后，发现细胞内测试金属积累增加，导致生长、色素含量（chl a、Phy 和 Car）和 PS II 光化学降低，对光合色素的破坏作用表现为（Phy > chl a> Car）。PS II 光化学的负效应是由于 JIP 动力学ϕP、F/F、ϕE、Ψ和 PI 值显著降低，除了 F/F 和 ABS/RC、TR/RC、ET/RC 和 DI/RC 等能量通量参数值显著升高所致。两种砷化物都导致氧化生物标志物显著升高，尽管抗氧化酶如 SOD、POD、CAT 和 GST 的活性明显升高，但体外和体内分析（O¯、HO 和 MDA 当量含量）均证实了这一点。研究得出的结论是，在两种砷化物中，亚砷酸盐对生长、光合色素、氧化应激生物标志物的影响更为显著，这表明抗氧化防御系统的弱诱导不足以克服砷酸盐的应激。
