WATER PERMEABILITY OF ISOLATED CUTICULAR MEMBRANES - A STRUCTURAL-ANALYSIS
WATER PERMEABILITY OF ISOLATED CUTICULAR MEMBRANES - A STRUCTURAL-ANALYSIS
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DOI：
10.1006/abbi.1995.1183
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发表时间：
1995-03-10
影响因子：
3.9
通讯作者：
HEREDIA, A
中科院分区：
文献类型：
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作者：
LUQUE, P;BRUQUE, S;HEREDIA, A
从成熟的绿色和成熟番茄中分离的角质膜的水渗透性。水果进行了调查。 H+形式的成熟番茄角质层的水渗透性强烈依赖于PH值，并且当外部溶液的PH值增加时渗透性增加。成熟绿色果实角质层的透水性高于成熟果实角质层，且对PH依赖性较低。将分离的水果角质层置于三种不同 pH 水平下的 Na+ 形式，并在外部溶液中的相应 pH 值下测量其水渗透性。水渗透率值与成熟番茄角质层中存在的类黄酮柚皮素和查尔酮苷元的羟基官能团的性质和交换能力以及两种类型角质层的酚酸有关。钠形式的成熟绿色角质层的透水性因其交换容量小而增加，而成熟番茄角质层的透水性在高pH值下达到饱和值。结果表明，类黄酮在控制水穿过这些膜的聚合物基质的运输中发挥着重要作用。对不同角质层的 X 射线衍射研究证实，当分离的角质层处于不同的同离子形式时，聚合物的结构发生变化。对基底间距的分析证实了番茄果实角质层的结构模型，其具有两个主要的疏水面间空间，宽度约为 1.0 和 0.45 nm。 (C) 1995 学术出版社
Water permeability of isolated cuticular membranes from mature green and ripe Lycopersicon esculentum Mill. fruits was investigated. The water permeability of ripe tomato cuticles in the H+ form was strongly dependent on PH and increased when the PH of the external solution increased. The water permeability of the cuticles of mature green fruits was higher than that of the ripe fruit cuticles and had a low PH dependence. The isolated fruit cuticles were put in the Na+ form at three different pH levels and their water permeabilities were measured at the respective pH values in the external solution. The water permeability values were related to the nature and exchange capacity of hydroxyl functional groups of the flavonoids naringenin and chalconaringenin present in the ripe tomato cuticles, and to the phenolic acids of both types of cuticles. Whereas the water permeability of the mature green cuticles in the sodium form increased according to their small exchange capacity, the water permeability of ripe tomato cuticles reached a saturation value at high pH. The results indicate that the flavonoids play an important role in the control of water transport across the polymer matrix of these membranes. X-ray diffraction study of the different cuticles confirmed structural changes in the polymer when the isolated cuticles were put in the different homoionic forms. Analysis of the basal spacings confirms a structural model of tomato fruit cuticle with two major hydrophobic interplanar spaces around 1.0 and 0.45 nm wide. (C) 1995 Academic Press, Inc.