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
+.