Ammonium N influences the uptakes, translocations, subcellular distributions and chemical forms of Cd and Zn to mediate the Cd/Zn interactions in dwarf polish wheat (Triticum polonicum L.) seedlings

Ammonium (NH₄⁺) would influence the uptake and translocation of Cd and Zn to mediate their interactions in wheat. Thus, the effects of NH₄⁺ on Cd and Zn uptake, translocation, subcellular distributions and Cd chemical forms in dwarf polish wheat (DPW, Triticum polonicum L.) under Cd, Zn and Cd + Zn stresses with lack or supply of NH₄⁺ was investigated. The biomasses of root and shoot were reduced by NH₄⁺. NH₄⁺ enhanced Cd and Zn uptakes, but inhibited their translocations. Under lack and supply of NH₄⁺, Zn inhibited Cd uptakes, but promoted Cd translocations. Meanwhile, NH₄⁺ reinforced the inhibition of Cd uptake and the promotion of Cd translocation caused by Zn. Cd inhibited Zn uptake and promoted Zn translocation under lack of NH₄⁺. Meanwhile, Cd slightly reduced the Zn uptake, but did not affect the translocation under supply of NH₄⁺. Therefore, NH₄⁺ alleviated the inhibition of Zn uptake and partly reduced the promotion of Zn translocation stimulated by Cd. NH₄⁺ and Zn changed the subcellular distributions and chemical forms of Cd. NH₄⁺ and Cd also influenced the subcellular distributions of Zn. The changed subcellular distributions and chemical forms were associated with Cd and Zn uptakes and translocations, which physiologically revealed and illustrated NH₄⁺participates in Cd/Zn interactions.