A cumulative assessment of plant growth stages and selenium supplementation on arsenic and micronutrients accumulation in rice grains

Arsenic (As) accumulation in rice grain and subsequent transmission into the food chain is a major global concern. Numerous attempts to minimize As accumulation in rice have been researched till date. The current investigation evaluates the relative susceptibility of different growth stages of rice plant to As stress in terms of As accumulation in grain at maturity using sixty treatment combinations. Our findings suggest that supplementing with selenium (Se) resulted in minimizing As content significantly (at P < 0.001 level) in grain, irrespective of growth stages where As stress was introduced. The findings registered the following order of susceptibility to As stress: flowering > grain filling > maximum tillering. Our findings also showed that Se primed rice plants restricts majority of As accumulation in the root itself and minimizes As translocation to the above ground part. The results of this study shows that cultivation of Se primed seeds can be (i) an effective means to minimize As accumulation in rice, and (ii) potential mode of biofortification of rice grain with essential nutrient elements {iron (8.47-10.17 mg L-1), zinc (7.14-8.05 mg L-1), manganese (17.92-19.71 mg L-1) and copper (3.18-3.28 mg L-1)} improving the recommended dietary intake of micronutrients, an invaluable strategy especially for malnourished rice dependent populations. Using machine learning this study also predicts that the Se concentration of 0.862 mg L-1 could be the most effective input in minimizing As content and enhancing other micronutrient content, irrespective of As stress.