A MUTANT OF ARABIDOPSIS WITH INCREASED LEVELS OF STEARIC-ACID
A MUTANT OF ARABIDOPSIS WITH INCREASED LEVELS OF STEARIC-ACID
复制标题
DOI：
10.1104/pp.106.4.1443
复制
发表时间：
1994-12-01
期刊：
影响因子：
7.4
通讯作者：
BROWSE, J
中科院分区：
文献类型：
--
作者：
LIGHTNER, J;WU, JR;BROWSE, J
拟南芥fab2位点的突变导致叶片中硬脂酸盐水平升高。叶片硬脂酸盐的增加在发育过程中是不同的，在幼叶中增加最多，其中硬脂酸盐几乎占叶片总脂肪酸的20%。从fab2突变体中分离的叶脂脂肪酸组成表明，叶绿体和叶绿体外膜的所有主要甘油脂中硬脂酸盐含量均有所增加。虽然硬脂酸含量增加了，但fab2突变体仍然含有大量的18:1、18:2和18:3脂肪酸。这些结果与预期的突变部分影响基质硬脂酰酰基载体蛋白去饱和酶的作用一致。位置分析表明，在叶绿体和叶绿体外甘油脂的sn-2位置上，额外的18:0被高特异性地排除在外。虽然硬脂酸含量在所有主要叶膜脂中都有所增加，但不同脂质的增加量差异很大，从磷脂酰胆碱脂肪酸的25%到单半乳糖二酰基甘油脂肪酸的2.9%不等。
A mutation at the fab2 locus of Arabidopsis caused increased levels of stearate in leaves. The increase in leaf stearate in fab2 varied developmentally, and the largest increase occurred in young leaves, where stearate accounted for almost 20% of total leaf fatty acids. The fatty acid composition of leaf lipids isolated from the fab2 mutant showed increased stearate in all the major glycerolipids of both the chloroplast and extrachloroplast membranes. Although the stearate content was increased, the fab2 mutant still contained abundant amounts of 18:1, 18:2, and 18:3 fatty acids. These results are consistent with the expectations for a mutation partially affecting the action of the stromal stearoyl-acyl carrier protein desaturase. Positional analysis indicated that the extra 18:0 is excluded with high specificity from the sn-2 position of both chloroplast and extrachloroplast glycerolipids. Although stearate content was increased in all the major leaf membrane lipids, the amount of increase varied considerably among the different lipids, from a high of 25% of fatty acids in phosphatidylcholine to a low of 2.9% of fatty acids in monogalactosyldiacylglycerol.