Polar localization of NRT1.8 mediates local nitrate uptake into root apical meristem and root development under cadmium stress

Heavy metal pollution and overuse of nitrogen fertilizer have essentially deteriorated soil environments, though how these two factors interact with each other and impact plant growth remains largely unknown. Here, we reported polar localization of NRT1.8 towards the soil side at epidermal cells adjacent to lateral root caps (LRC). The combined treatment of Cd and nitrate induced NRT1.8 expression at root tips, leading to uptake of more NO3- from LRC into inner meristem cells. Decrease of root length and meristematic cell numbers was observed in nrt1.8 mutant than the wild-type control only when exposed to the combined treatment.