Analysis of physiological and biochemical responses of black rice(Oryza sativa L.) to arsenic stress
Abstract
Due to various biogeochemical and anthropogenic activities, the elevated concentration of arsenic (As) in soil and groundwater is a prevalent problem in India. This affects the growth of crops and thereby threatens the health of humans as well. Arsenic gets accumulated majorly in the rice plants and rice is a staple food for large population in India. Therefore, it is necessary to select a suitable low-As accumulating and nutrient enriched rice variety for cultivation in As contaminated areas. This work was conducted on black rice, which is a highly nutritious variety in comparison to white rice, and its responses to As stress (20 μM) were evaluated for 7 and 12 days. The response was monitored in terms of various physiological and biochemical parameters, like root and shoot length, photosynthetic pigments, and antioxidant enzymes. Arsenic affected the growth of the rice seedlings negatively with decline in root and shoot length and weight. The As induced oxidative stress was evident through increase in MDA level. However, the potential of black rice to tolerate As stress was demonstrated by increase in the activity of antioxidant enzymes and cysteine biosynthesis. Black rice is a nutritionally enriched rice variety that may be, cultivated in As stressed environment. However, more research is needed on this variety.
