SlAGO4A, a core factor of RNA-directed DNA methylation (RdDM) pathway, plays an important role under salt and drought stress in tomato
SlAGO4A, a core factor of RNA-directed DNA methylation (RdDM) pathway, plays an important role under salt and drought stress in tomato
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SlAGO4A是RNA介导的DNA甲基化(RdDM)途径的核心因子，在番茄盐和干旱胁迫下发挥重要作用
DOI：
10.1007/s11032-016-0439-1
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发表时间：
2016-03-01
影响因子：
3.1
通讯作者：
Li, Zhengguo
中科院分区：
文献类型：
--
作者：
Huang, Wei;Xian, Zhiqiang;Li, Zhengguo
在拟南芥中，已经阐明AGO 4蛋白参与称为RNA指导的DNA甲基化（RdDM）的现象。在此之前，在番茄中克隆了四个AtAGO 4的直系同源物，命名为SlAGO 4A-SlAGO 4D。在这里，我们研究了SlAGO 4A基因在调节番茄耐盐性和耐旱性中的作用。SlAGO 4A下调（AS）转基因番茄植株表现出比野生型（WT）和SlAGO 4A过表达（OE）转基因植株增强的对盐和干旱胁迫的耐受性，如通过生理参数如种子萌发率、初生根长度、叶绿素/脯氨酸/MDA/可溶性糖/RWC含量和存活率评估的。此外，一些参与ROS清除和植物防御的基因，包括CAT，SOD，GST，POD，APX，LOX和PR 1，在盐和干旱胁迫下一致上调或下调。值得注意的是，一些DNA甲基转移酶基因和RNAi途径基因的表达水平在AS植物中显著低于WT。这些结果表明，SlAGO 4A基因在盐胁迫和干旱胁迫下可能通过调控DNA甲基化和经典的RNAi途径发挥负作用。因此，它可以作为一个有用的生物技术工具，遗传改良作物的耐逆性。
In Arabidopsis, it has been clarified that AGO4 protein is implicated in a phenomenon termed RNA-directed DNA methylation (RdDM). Previously, four orthologs of AtAGO4 were cloned in tomato, designated as SlAGO4A-SlAGO4D. Here, we studied the role of the SlAGO4A gene in regulating salt and drought tolerance in tomato. SlAGO4A-down-regulating (AS) transgenic tomato plants showed enhanced tolerance to salt and drought stress compared to wildtype (WT) and SlAGO4A-overexpressing (OE) transgenic plants, as assessed by physiological parameters such as seed germination rate, primary root length, chlorophyll/proline/MDA/soluble sugar/RWC content, and survival rate. Moreover, several genes involved in ROS scavenging and plant defense, including CAT, SOD, GST, POD, APX, LOX, and PR1, were up-or down-regulated consistently under salt and drought stress. Notably, expression levels of some DNA methyltransferase genes and RNAi pathway genes were significantly lower in AS plants than in WT. Taken together, our results suggest that SlAGO4A gene plays a negative role under salt and drought stress in tomato probably through the modulation of DNA methylation as well as the classical RNAi pathway. Hence, it may serve as a useful biotechnological tool for the genetic improvement of stress tolerance in crops.