Salt-induced perturbation in growth, physiological attributes, activities of antioxidant enzymes and organic solutes in mungbean (Vigna radiata L.) cultivars differing in salinity tolerance

Abstract

A pot experiment was conducted to appraise the inhibitory effects of salt stress on biochemical attributes in the three mungbean cultivars (NCM-209, NCM-89 and NM-92). Salt stress caused a significant decrease in plant height, shoot relative water contents, photosynthetic pigments, endogenous levels of K⁺ and K⁺/Na⁺ ratios and increase in cellular levels of H₂O₂, MDA, Na⁺ and Cl⁻. However, cv. NCM-209 was found to be tolerant in terms of lower salt-induced decline in K⁺, K⁺/Na⁺ ratio and photosynthetic pigments. The endogenous levels of H₂O₂ and MDA were also lower in cv. NCM-209. Salt stress markedly also affected different yield attributes in all mungbean cultivars. Again cultivar NCM-209 exhibited less inhibitory effects of salt stress on different growth attributes. Salt stress resulted in a marked increase in the activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase) in mungbean cultivars. Activity of peroxidase was maximal in cv. NCM-209 and catalase activity was maximal in cv. NCM-89, whereas cvs. NCM-89 and NM-92 showed higher activities of superoxide dismutase. Similarly activity of ascorbate peroxidase was higher in cv. NM-92. It could be inferred from data of antioxidant enzymes that mungbean cultivars cannot be categorized as salt tolerant or sensitive on the basis of a single antioxidant enzyme.

Keywords:

• peroxidase
• catalase
• H₂O₂
• superoxide dismutase
• malondialdehyde
• nutrients