Unraveling the role of OsPIP1;3 in arsenic transport in rice (Oryza sativa L.)

Rice is the main diet for more than half of the world’s population; thus, it gains special interest to ensure it is safe for consumption. Growing rice, especially in flooded paddy fields where the soil or irrigation water is contaminated with Arsenic (As) favors rice to accumulate it in biomass and edible grains. Thus, rice is the primary source of dietary As contamination, which is a major health hazard. Understanding the mechanism of As uptake and developing approaches to restrict the movement of As from soil to different plant tissues are necessary to limit As accumulation in rice. This study investigates the role of rice plasma membrane intrinsic protein, OsPIP1;3, in As transport and translocation from root to shoot in rice. Suppression of OsPIP1;3 expression using RNAi (Ri) technology decreases As accumulation in the shoots of transgenic OsPIP1;3 Ri plants by (45.3–45.6%), with no noticeable effect on root arsenic levels. In contrast, constitutive overexpressing (OE) OsPIP1;3 increased As in shoots of rice seedlings by 8–29%, with no significant change in root As content compared with WT. At the maturity stage, OsPIP1;3 Ri plants accumulated (29–36%) and (5–21%) less As in shoot and flag leaves, respectively, while grains show a slight reduction. Similar to the seedling stages, OsPIP1;3 OE mature plants accumulated significantly high As levels in their shoots, flag leaves, and grains compared to WT. Together, these results suggest that OsPIP1;3 contribute to As transport from root to shoot in rice. This finding could add to the current knowledge of As transporters, which are collectively considered a major genetic source for manipulation to reduce As accumulation in rice and other food crops for improved human and environmental health.