脂肪酸对盐胁迫大麦幼苗液泡膜微囊膜脂组分及功能的影响

Effects of Fatty Acids on Lipid Composition and Function of Tonoplast Vesicles in Barley Seedlings Under Salt Stress 

用１００ｍｍｏｌ／ＬＮａＣｌ处理大麦（ＨｏｒｄｅｕｍｖｕｌｇａｒｅＬ．）幼苗２ｄ，根系液泡膜微囊膜脂不饱和度上升，并不随外源脂肪酸的饱和度而改变。外源硬脂酸和亚油酸降低大麦幼苗对Ｎａ＋的吸收及其向地上部的运输，增加Ｋ＋的吸收和向地上部的运输，降低根系的电解质渗漏率。增加液泡膜磷脂、糖脂结合半乳糖含量及Ｈ＋ＡＴＰａｓｅ和Ｈ＋ＰＰａｓｅ（焦磷酸酶）活性，与它们调节大麦对离子的吸收、分配的结果相一致，硬脂酸和亚油酸均有一定程度的缓解盐害的效应。

When barley (Hordeum vulgare L.) seedlings were treated with 100 mmol/L NaCl for 2 d, the index of unsaturated fatty acid (IUFA) increased in the tonoplast vesicles that were isolated from the seedlings roots of two barley cultivars with different salt tolerance, whereas no change were observed when the seedlings were treated with exogenous fatty acids with different saturability. Exogenous stearic acid and linoleic acid decreased Na + absorption and transportation to the shoots, increased K + absorption and transportation, decreased the leakage of electrolytes, and increased the phospholipid and galactose contents of lipids in tonoplast, enhanced the activities of tonoplast H + ATPase and H + PPase. This is consistent with the results that the two fatty acids, linoleic acid and stearic acid, regulate ion absorption and distribution, mitigate salt stress to some extent, the effects of linoleic acid being more the latter.