Freezing Tolerance in Plants Requires Lipid Remodeling at the Outer Chloroplast Membrane
Freezing Tolerance in Plants Requires Lipid Remodeling at the Outer Chloroplast Membrane
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DOI：
10.1126/science.1191803
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发表时间：
2010-10-08
期刊：
影响因子：
56.9
通讯作者：
Benning, Christoph
中科院分区：
文献类型：
--
作者：
Moellering, Eric R.;Muthan, Bagyalakshmi;Benning, Christoph
植物对冷冻表现出复杂的适应性，可以防止细胞脱水造成的细胞损伤。在脱水过程中细胞膜的脂质重塑是对抗膜完整性丧失和细胞死亡的一个关键机制。FREEZING 2（SFR2）是拟南芥抗冻性基因，编码叶绿体外膜半乳糖脂重塑酶。SFR2原酰基转移半乳糖残基从丰富的单半乳糖脂到不同的半乳糖脂受体，形成寡聚半乳糖脂和二酰基甘油，其进一步转化为三酰基甘油。SFR 2和三酰甘油生物合成酶的组合活性导致单半乳糖脂从包膜膜中去除，改变双层与非双层形成膜脂质的比率。这种基于SFR2的机制可以补偿细胞器体积的变化，并在冷冻过程中稳定膜。
Plants show complex adaptations to freezing that prevent cell damage caused by cellular dehydration. Lipid remodeling of cell membranes during dehydration is one critical mechanism countering loss of membrane integrity and cell death. SENSITIVE TO FREEZING 2 (SFR2), a gene essential for freezing tolerance in Arabidopsis, encodes a galactolipid remodeling enzyme of the outer chloroplast envelope membrane. SFR2 processively transfers galactosyl residues from the abundant monogalactolipid to different galactolipid acceptors, forming oligogalactolipids and diacylglycerol, which is further converted to triacylglycerol. The combined activity of SFR2 and triacylglycerol-biosynthetic enzymes leads to the removal of monogalactolipids from the envelope membrane, changing the ratio of bilayer-to non-bilayer-forming membrane lipids. This SFR2-based mechanism compensates for changes in organelle volume and stabilizes membranes during freezing.