Membrane-Potential Alteration During K+ Uptake of Different Salt-Tolerant Wheat Varieties

K+ is the most abundant cation in plant cells and plays an important role in many ways.K+ uptake of plant has respect to its salt resistant capacity.There are two categories of channel transportation for plants to uptake K+,one is through K+ channels and the other is through nonselective cation channels(NSCCs).The transmembrane localization of K+ may change membrane potential(MP).In this paper,three wheat varieties with different salt tolerance were selected and the MP was measured by microelectrode during K+ uptake.The results showed that the effects of K+ uptake on MP through K+ channels or NSCCs were distinct.K+ influx through K+ channels led to MP hyperpolarization,while K+ influx through NSCCs resulted in depolarization.Diverse MP alteration of wheat varieties with different salt tolerance was mainly due to NSCCs-mediated K+ uptake.Compared with the salt-tolerant wheat,the MP hyperpolarization during K+ uptake of saltsensitive wheat was much more evident,probably because of the cation outflux through NSCCs during this process.