Mono- and Digalactosyldiacylglycerol Lipids Function Nonredundantly to Regulate Systemic Acquired Resistance in Plants
Mono- and Digalactosyldiacylglycerol Lipids Function Nonredundantly to Regulate Systemic Acquired Resistance in Plants
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DOI：
10.1016/j.celrep.2014.10.069
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发表时间：
2014-12-11
期刊：
影响因子：
8.8
通讯作者：
Kachroo, Pradeep
中科院分区：
文献类型：
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作者：
Gao, Qing-ming;Yu, Keshun;Kachroo, Pradeep
植物半乳糖脂单半乳糖二酰甘油 (MGDG) 和二半乳糖二酰甘油 (DGDG) 能够调节一氧化氮 (NO) 等自由基的水平，因此与绿叶蔬菜饮食的抗炎和抗癌功效有关。在这里，我们表明 DGDG 有助于植物 NO 以及水杨酸的生物合成，并且是诱导系统获得性抗性 (SAR) 所必需的。相反，MGDG 调节在 NO 下游发挥作用的 SAR 信号壬二酸 (AzA) 和 3-磷酸甘油 (G3P) 的生物合成。有趣的是，AzA 诱导的 SAR 也需要 DGDG，但 MGDG 则不需要。值得注意的是，细菌葡萄糖基转移酶的转基因表达无法恢复 dgd1 植物中的 SAR，尽管它确实挽救了它们的形态和脂肪酸表型。这些结果表明，在 SAR 诱导过程中，MGDG 和 DGDG 在不同的步骤中是必需的，并且仅在其各自的角色中发挥作用。
The plant galactolipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) have been linked to the anti-inflammatory and cancer benefits of a green leafy vegetable diet in humans due to their ability to regulate the levels of free radicals like nitric oxide (NO). Here, we show that DGDG contributes to plant NO as well as salicylic acid biosynthesis and is required for the induction of systemic acquired resistance (SAR). In contrast, MGDG regulates the biosynthesis of the SAR signals azelaic acid (AzA) and glycerol-3-phosphate (G3P) that function downstream of NO. Interestingly, DGDG is also required for AzA-induced SAR, but MGDG is not. Notably, transgenic expression of a bacterial glucosyltransferase is unable to restore SAR in dgd1 plants even though it does rescue their morphological and fatty acid phenotypes. These results suggest that MGDG and DGDG are required at distinct steps and function exclusively in their individual roles during the induction of SAR.