Alleviation of salinity triggered oxidative damage and photoinhibition in Vigna radiata by individual and combined treatments of selenium and jasmonic acid

Abstract

Experiments were performed to evaluate the effect of selenium (Se) and methyl jasmonate (Me-JA) in alleviating the salinity (100 mM NaCl) stress triggered decline in growth and photosynthetic in Vigna radiata. Salinity stress significantly reduced the growth measured in terms of plant height and dry mass which was significantly alleviated by Se and /or Me-JA. Treatment of Se and Me-JA increased the synthesis of prototoporphyrin IX (Proto IX), Mg-prototoporphyrin IX (Mg-Proto IX), chlorophylls and carotenoids, increased photosynthesis and PSII activity. Besides, the supplementation of Se and Me-JA significantly declined the reactive oxygen species (H2O2 and O2-) levels causing increased membrane stability. Treatment of Se and MeJA up-regulated the antioxidant system by increasing the activities of superoxide dismutase, ascorbate peroxidase and glutathione reductase, and the content of ascorbate and glutathione in both control and salt stress treated plants. The Se and Me-JA treatment significantly increased the synthesis of total phenols and flavonoids reflecting in increased total antioxidant activity. Accumulation of proline, sugars, glycine betaine and the activity of γ-glutamyl kinase was significantly improved in Se and Me-JA treatments affecting the tissue water content. Decline in nitrate reductase activity due to salinity stress was alleviated significantly due to Se and Me-JA treatment. Vigna radiata plants treated with Se and Me-JA accumulated less Na and more K and N compared to salt stressed plants.