Physiological and Biochemical Changes in Moth Bean (Vigna aconitifolia L.) under Cadmium Stress

摘要

Moth bean (Vigna aconitifolia L.), a drought resistant legume, possesses high nutritional value. Cadmium (Cd) is a nonessential and the most toxic heavy metal in plants. The present study was to test the hypothesis of whether moth bean being a drought resistant legume can withstand the cadmium stress. Ten-day-old moth bean seedlings were subjected to cadmium stress and investigated for a period of 15 days every 3-day intervals. Cadmium quantification in moth bean tissues suggests root accumulation and translocation to aerial parts in a concentration dependent manner. Results of physiological and biochemical studies revealed that cadmium has affected the growth parameters like shoot and root lengths and tissue dry weights. Significant alternations in relative water content and cell membrane stability were observed in stressed seedlings. Similarly superoxide radical, lipoxygenase activity, membrane lipid peroxidation products, protein carbonyls, and reduced glutathione and nonprotein thiols were found increased in stressed seedlings compared to controls. However, hydrogen peroxide and ascorbic acid levels were not altered significantly in both stressed and control seedlings. Cadmium translocation ability from roots to aerial parts and elevated levels of nonenzymatic antioxidants in stressed seedlings suggest the cadmium stress withstanding ability of moth bean.