【摘要】 氮源是植物生长发育必需的大量元素,铵作为重要的无机氮源主要由根部吸收.植物需维持细胞内相对稳定的铵稳态,过量铵会导致植物铵中毒.植物细胞的铵受体可以感知胞内外铵浓度的变化,由相应的铵转运体将铵从胞外转运到胞内,启动铵信号依赖的基因转录和蛋白磷酸化,通过调控铵的吸收、同化,以及胞内铵的区域化,维持细胞内铵的稳态平衡.本文简要总结了植物铵毒害的机制,铵稳态调控的吸收、同化及区域化的最新研究进展,铵信号在调控植物细胞铵稳态平衡中的机制,并对未来研究中应该关注的研究方向进行了分析讨论.更多还原

【Abstract】 Nitrogen is an essential macronutrient in plant growth and development. Ammonium is one of the major inorganic nitrogen forms for root uptake. The homeostasis of ammonium in the plant cell is under tight control to prevent ammonium toxicity when in excess. In the ammonium signaling pathway, internal and external ammonium can be detected by specific sensors, which in turn triggers a series of proper plant ammonium responses including transcription regulation and phosphorylation. Ammonium absorption is mainly mediated by the root-located ammonium transporters,which are key regulators in the nitrogen signaling pathway.Many researchers have attempted to unravel the mechanisms of ammonium uptake by the transporters. Fine-tuned modulation of ammonium homeostasis is necessary to maintain an appropriate level of ammonium in the cytoplasm,which is a balance of ammonium efflux, assimilation and compartmentation. Recently, there has been important progress in revealing the ammonium sensing and signaling mechanisms. In this review, we focus on the homeostatic regulation and signaling of cytosolic ammonium.更多还原