Nitrate N influences the accumulations and subcellular distributions of Cd and Zn to mediate the Cd/Zn interactions in dwarf Polish Wheat (Triticum polonicum L.) seedlings

ABSTRACTNitrate (NO3–) assimilation and transport play important roles in Cd transport. Transcript profiling indicated that several NO3− metabolism-related genes were involved in Cd/Zn interactions in roots of dwarf Polish Wheat (DPW). In this study, the effects of NO3− on Cd and Zn accumulations and subcellular distributions in DPW under Cd, Zn, and Cd + Zn applications with lack or supply of NO3− were investigated. Compared with lack of NO3–, supply of NO3− enhanced the Cd accumulation and the NO3− uptake in roots under Cd application; it reduced the Zn accumulation and the NO3− uptake in roots under Zn application; it did not affect the Cd accumulation and the NO3− uptake, but reduced the Zn accumulation in roots under Cd + Zn application. Supply of NO3− increased the Cd concentration in soluble fraction (including vacuole) to enhance the Cd capacity in roots under Cd application; it reduced the Zn concentration in soluble fraction under Zn application, and in all fractions under Cd + Zn application. U...