渗透胁迫对小麦根质膜膜脂物理状态的影响

以两相法纯化的小麦(Triticum sativum L.)根质膜微囊为材料，研究了渗透胁迫下质膜物理状态的变化。结果表明，随着介质蔗糖浓度增加，质膜光散射值降低，二苯己三烯(DPH)荧光偏振值升高，MC540荧光强度增强，并且DPH长寿命组分的荧光寿命和平均寿命都缩短，暗示渗透胁迫使质膜微囊收缩变小，降低了质膜流动性和表面电荷密度，并且表明质膜的疏水性减弱。进一步实验发现，质膜内源色氨酸长寿命组分的寿命缩短，质膜H

Influence of Osmotic Stress on the Lipid Physical States of Plasma Membranes from Wheat Roots

The plasma membrane vesicles were purified from wheat ( Triticum sativum L. ) roots by the two phase partitioning method. The results showed that with the increase in sucrose concentrations, light scattering was decreased, diphenyl hexatriene (DPH) polarization and merocyanine 540 (MC540) fluorescence intensity increased, indicating that under osmotic stress the vesicles were getting smaller, the membrane fluidity and surface charge density were decreased. Further experiments showed that the long lifetime and average lifetime of DPH fluorescence decreased under stress, suggesting that plasma membrane hydrophobicity decreased. The long lifetime fluorescence of intrinsic tryptophan was also decreased, indicating that the polarity of the microenvironment surrounding the tryptophan was increased, i.e. protein conformation changed; It was also found that the H + -ATPase activity decreased with the increase in sucrose concentrations, suggesting that the membrane protein function was also affected by the physical state under osmotic stress.