盐胁迫对高粱根质膜离子通道通透性的影响

用１００ ｍ ｍ ｏｌ／Ｌ、２００ ｍ ｍ ｏｌ／Ｌ、３００ ｍ ｍ ｏｌ／ＬＮａＣｌ依次处理萌发后３ ｄ 的高粱（Ｓｏｒｇｈｕｍｖｕｌｇａｒｅ Ｐｅｒｓ．）幼苗，分离纯化根质膜。将质膜嵌入预先涂制好的平面脂双层，然后用电学方法测定该脂双层的离子选择通透性。膜的两测分别加入ＮａＣｌ和ＫＣｌ，在电压钳位下测定不同膜电位时的膜电流，通过ＧＨＫ 电压等式计算膜的离子选择通透性。结果表明质膜的离子选择通透性在盐胁迫下发生显著变化，对照的Ｋ＋ 、Ｎａ＋ 通透比（ＰＫ∶ＰＮａ）＝ ３．５，处理后ＰＫ∶ＰＮａ＝ １．５。讨论了这一变化的含义

EFFECTOFSALTSTRESSONIONCHANNELSELECTIVE PERMEABILITY OF PLASMALEMMA IN SORGHUM ROOTS

mmol/L, 200 mmol/L and 300 mmol/L NaCl was used in proper order to treat three day old seedlings of Sorghum vulgare Pers. The plasma membrane of roots was iso lated and purified by aqueous biphasic partition device.The plasmalemma was incorporated into planar bilayer lipid membrane and ion channels were measured by electrical methods.Ion selective permeabilities (P K:P Na ) were assayed in asymmetrical solutions containing 100 mmol/L NaCl in Cis chamber and 100 mmol/L KCl in Tran with chamber and were calculated from Goldman Hodgkin Kaltz equation.P K: P Na was 3 5 in plasmalemma of control roots and 1 5 in plasmalemma of salt stressed roots.It showed that the changes of ion selective permeability was very significant under salt stress.The importance of the change of ion selective permeability is disscuted.