Acyl-lipid desaturase 1 primes cold acclimation response in Arabidopsis
Acyl-lipid desaturase 1 primes cold acclimation response in Arabidopsis
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DOI：
10.1111/ppl.12448
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发表时间：
2016-09-01
影响因子：
6.4
通讯作者：
Thelen, Jay J.
中科院分区：
文献类型：
--
作者：
Chen, Mingjie;Thelen, Jay J.
膜流动性变化一直被认为是植物适应低温胁迫的主要机制，但其分子机制尚未完全阐明。在这项研究中，我们发现，敲除酰基脂质/辅酶A去饱和酶1基因（ADS 1; EC 1.14.99）增强冷驯化（CA）后的抗冻性。脂肪酸组成分析表明，在23 ℃下生长的ads 1突变体植物中的18：1含量比野生型（WT）低20%。脂质组学显示，在ads 1突变体中的单半乳糖基二酰甘油（MGDG）含量比野生型低3.3-14.9%。脂质位置分析确定了MGDG的sn-2位的18：1脂肪酸含量降低10%。细胞质钙含量在ads 1突变体植物也约2倍高于野生型响应冷休克。WT和ads 1突变体之间的这些生化差异在CA后消失。亚细胞定位的C-和N-末端增强荧光融合蛋白表明，ADS 1只定位于叶绿体。这些观察结果表明，ADS 1介导的叶绿体膜流动性的改变是引发CA反应所必需的，并且是胞质钙信号传导的上游事件。
Membrane fluidity change has long been suggested as the primary mechanism by which, plants adapt to cold stress, but the underlying molecular mechanisms are not completely established. In this study, we found that a knockout of acyl-lipid/CoA desaturase 1 gene (ADS1; EC 1.14.99) enhances freezing tolerance after cold acclimation (CA). Fatty acid composition analysis demonstrated that 18:1 content in ads1 mutant plants was 20% lower than in wild-type (WT) grown at 23 degrees C. Lipidomics revealed that 34C-species of monogalactosyl diacylglycerol (MGDG) content in ads1 mutants were 3.3-14.9% lower than in WT. Lipid positional analysis identified 10% lower 18:1 fatty acid content at the sn-2 position of MGDG. The cytosolic calcium content in ads1 mutant plants was also approximately two-times higher than that of WT in response to cold shock. Each of these biochemical differences between WT and ads1 mutant disappeared after CA. Subcellular localization of C- and N-terminal enhanced-fluorescence-fusion proteins indicated that ADS1 localized exclusively to chloroplasts. These observations suggest that ADS1-mediated alteration of chloroplast membrane fluidity is required to prime a CA response, and is the upstream event of cytosolic calcium signaling.