Cooke D T, Munkonge F M, Burden R S, James C S
Department of Agricultural Sciences, University of Bristol, U.K.
Biochim Biophys Acta. 1991 Jan 30;1061(2):156-62. doi: 10.1016/0005-2736(91)90280-l.
Oat and rye plants were treated with either tetcyclacis (an experimental plant growth regulator), nuarimol (a fungicide) or gamma-ketotriazole (an experimental herbicide). These treatments reduced shoot growth and changed the lipid composition of the shoot plasma membranes. In oat, both tetcyclacis and nuarimol treatments increased plasma membrane cholesterol and increased the phosphatidylethanolamine/phosphatidylcholine (PE/PC) ratio, whereas gamma-ketotriazole treatment reduced cholesterol and the PE/PC ratio. In rye, all treatments reduced the PE/PC ratio. Generally, the sterol/phospholipid ratio was less in oat than in rye but the cholesterol/phospholipid ratio was greater. With all treatments in oat and rye, increases were observed in unsaturation of the phospholipid acyl chains. The fluidity of membranes was measured by steady-state fluorescence polarisation of the probe diphenylhexatriene; oat membranes were more fluid than rye. Membrane fluidity was greater in plasma membranes from plants treated with the xenobiotics than the controls. The results are discussed in the context of the effect of plasma membrane lipid composition on membrane fluidity, and it is concluded that there appears to be no overall simple relationship between membrane lipid composition and fluidity that holds for all treatments in both species.
燕麦和黑麦植株分别用四环菌酸（一种实验性植物生长调节剂）、氯苯嘧啶醇（一种杀菌剂）或γ-酮三唑（一种实验性除草剂）进行处理。这些处理降低了地上部生长，并改变了地上部质膜的脂质组成。在燕麦中，四环菌酸和氯苯嘧啶醇处理均增加了质膜胆固醇含量，并提高了磷脂酰乙醇胺/磷脂酰胆碱（PE/PC）比值，而γ-酮三唑处理则降低了胆固醇含量和PE/PC比值。在黑麦中，所有处理均降低了PE/PC比值。一般来说，燕麦中的甾醇/磷脂比值低于黑麦，但胆固醇/磷脂比值则高于黑麦。在燕麦和黑麦的所有处理中，均观察到磷脂酰基链不饱和度增加。通过探针二苯基己三烯的稳态荧光偏振来测定膜的流动性；燕麦膜比黑麦膜流动性更大。用外源化合物处理的植株质膜的流动性比对照更大。本文在质膜脂质组成对膜流动性影响的背景下对结果进行了讨论，并得出结论：在这两个物种的所有处理中，膜脂质组成与流动性之间似乎不存在普遍适用的简单关系。
