高等植物K^+吸收及转运的分子机制研究进展

Advances in understanding molecular mechanisms of K^+ uptake and transport in higher plants

K^+是植物生长必需的营养元素。K^+被植物根系吸收后,有效地向地上部转运,在跨膜转运的过程中主要由次级K^+转运蛋白和K^+通道介导。KT/HAK/KUP和HKT家族是参与植物体内K+吸收及转运的两类主要K+转运蛋白,其中HKT家族参与K^+转运的成员仅存在于单子叶植物中,它们在植物生长发育、渗透调节等过程中均发挥重要作用。Shaker家族是K^+通道中最早发现且研究最为深入的一类电压门控型通道,是植物K^+吸收的重要途径之一。本研究从结构特征、定位和组织表达、功能调控等方面对植物KT/HAK/KUP家族、HKT家族和Shaker通道进行综述,最后对未来的主要研究方向做了展望。

As one of the major nutrients,potassium(K^+)is essential for plant growth and development.Large amounts of K^+need to be taken up from the soil and transported throughout the plant.The K^+transporters and the K^+channels mainly mediate K^+transport across the plasma membrane and the tonoplast membrane in plants.The HAK/KUP/KT family and the HKT family are two main groups of proteins which have been widely associated with K^+uptake and transport,and they fulfill diverse roles in plant growth processes,salt tolerance and osmotic potential regulation.K^+-permeable members of HKT family seem to be present in monocots only.The Shaker family,comprising voltage-gated channels,dominate the plasma membrane conductance of K^+in most environmental conditions.This review summarizes recent research and progress in understanding of the structure,localization,expression,function and regulation of three main K^+transport families.We also propose research hotspots and directions for future K^+research.