A MUTANT OF ARABIDOPSIS DEFICIENT IN DESATURATION OF PALMITIC ACID IN LEAF LIPIDS
A MUTANT OF ARABIDOPSIS DEFICIENT IN DESATURATION OF PALMITIC ACID IN LEAF LIPIDS
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DOI：
10.1104/pp.90.3.943
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发表时间：
1989-07-01
期刊：
影响因子：
7.4
通讯作者：
SOMERVILLE, C
中科院分区：
文献类型：
--
作者：
KUNST, L;BROWSE, J;SOMERVILLE, C
拟南芥突变体的叶脂总脂肪酸组成的特征是棕榈酸的含量增加，而不饱和的16碳脂肪酸的含量减少。对单个脂质的脂肪酸组成的定量分析表明，该突变体缺乏叶绿体ω9脂肪酸去饱和酶的活性，该酶通常在酯化为单半乳糖二酰甘油(MGD)的16碳酰化链中引入双键。突变体在MGD中表现出18-到16-碳脂肪酸的比例增加，这是由于原核生物和真核生物脂质生物合成途径的相对贡献发生了变化。这似乎是对叶绿体ω9去饱和酶的一种受调控的反应，并可能反映了叶绿体膜的正常组装所需的多不饱和脂肪酸。原核MGD物种质量的减少既包括原核途径合成MGD的减少，也包括16：0 MGD分子物种周转的增加。
The overall fatty acid composition of leaf lipids in a mutant of Arabidopsis thalliana was characterized by elevated amounts of palmitic acid and a decreased amount of unsaturated 16-carbon fatty acids as a consequence of a single nuclear mutation. Quantitative analysis of the fatty acid composition of individual lipids suggested that the mutant is deficient in the activity of a chloroplast .omega.9 fatty acid desaturase which normally introduces a double bond in 16-carbon acyl chains esterified to monogalactosyldiacylglycerol (MGD). The mutant exhibited an increased ratio of 18- to 16-carbon fatty acids in MGD due to a change in the relative contribution of the prokaryotic and eukaryotic pathways of lipid biosynthesis. The appears to be a regulated response to the loss of chloroplast .omega.9 desaturase and presumably reflects a requirement for polyunsaturated fatty acids for the normal assembly of chloroplast membranes. The reduction in mass of prokaryotic MGD species involved both a reduction in synthesis of MGD by the prokaryotic pathway and increased turnover of MGD molecular species which contain 16:0.