Arsenic accumulation and tolerance in rootless macrophyte Najas indica are mediated through antioxidants, amino acids and phytochelatins

作者：Tripathi Rudra Deo^*; Singh Ragini; Tripathi Preeti; Dwivedi Sanjay; Chauhan Reshu; Adhikari Bijan; Trivedi Prabodh Kumar

来源：Aquatic Toxicology, 2014, 157: 70-80.

DOI：10.1016/j.aquatox.2014.09.011

• Amino acid
• Antioxidants
• Arsenate
• Arsenite
• Najas indica
• Phytochelatin

Arsenic (As) accumulation and tolerance response of a submerged rootless macrophyte Najas indica were evaluated during arsenate (As-v; 10-250 mu M) and arsenite (As-III; 1-50 mu M) exposure. Higher As accumulation at As-III exposure and more tolerance upon AS(V) exposure resulted in more toxicity during As-III stress than AS(V), which was evident through measurement of growth parameters and oxidative stress related parameters viz., lipid peroxidation (MDA content), electrical conductivity (EC) and hydrogen peroxide (H2O2) levels. Antioxidant enzymes and various amino acids were more prominent during moderate exposure of As-v, suggesting their possible role in As tolerance and detoxification. Various nonenzymatic antioxidant metabolites viz., ascorbic acid (ASC), glutathione (GSH), non-protein thiols (NPTs) and phytochelatins (PCs) biosynthesis involving phytochelatin synthase (PCS) activity increased more significantly during As-III stress. However, PCs content seems inadequate in response to As accumulation leading to lower PC-SH:As molar ratio and higher As phytotoxicity during As-III stress. N. indica may prove useful plant species for phytoremediation purpose in moderately As contaminated water bodies due to high As accumulation and tolerance potential.

• 出版日期2014-12