摘要:
根细胞膜上存在各种离子通道.电生理学的研究表明,根细胞离子通道对于矿质吸收、转运及植物耐盐具有重要作用.该文概述了根细胞K+通道、阴离子通道和各种非选择性阳离子通道的最新研究进展,并对近期有关离子通道和植物耐盐性关系的研究进行了总结.K+通道存在于大多数的植物细胞中,其对K+的选择性远高于其他阳离子,K+通道的存在对于营养元素的吸收,尤其是K+的低亲和性吸收具有重要的意义,同时也为其他离子的出入维持了一个较为稳定的膜电势.阴离子通道激活所引起的质膜去极化可以激发非选择性的阳离子流,在盐胁迫下,可通透Cl-的阴离子通道的开放是植物对胞内Cl-的一种重要调控机制.由于非选择性的阳离子通道(Non-selective cation channels,NSCCs)的多样性及其对一价阳离子的低选择性,近年来NSCCs的研究受到广泛关注.NSCCs被认为参与了植物多种生理过程,包括营养元素的吸收、膨压控制、胞间转运、信号转导以及毒害离子的吸收,尤其是Na+的吸收.
Abstract:
A variety of ion channels have been identified in root cell membranes.Electrophysiological studies have shown that ion channels play an important role in mineral uptake, translocation and salt resistance. K + channels, non-selective cation channels,Na+-permeable cation channels and anion channels in roots are introduced in this review.Furthermore,the ion channel-regulated salt uptake and the contribution to salinity tolerance are briefly reviewed. K +-channels,characterized in a wide variety of plant cells,are highly selective for K + over other monovalent cations. They play important roles in nutrient acquisition, especially in low-affinity potassium absorption and membrane voltage control.Activation of anion channels gives rise to the depolarization of plasma membrane,and evokes non-selective currents. It is suggested that the opening of Cl --permeable channels contribute to the regulation of net Cl --uptake under salinity. In recent years,non-selective cation channels have attracted more attention because of their diversity and low selectivity for monovalent cations,which also implies that they are involved in a wide range of plant processes,including nutrient acquisition,turgor control,intracellular ion transport,signaling and uptake of toxic cations,especially Na +.
百度学术
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