Cotton Major Latex Protein 28 Functions as a Positive Regulator of the Ethylene Responsive Factor 6 in Defense against Verticillium dahliae
Cotton Major Latex Protein 28 Functions as a Positive Regulator of the Ethylene Responsive Factor 6 in Defense against Verticillium dahliae
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DOI：
10.1016/j.molp.2014.11.023
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发表时间：
2015-03-02
期刊：
影响因子：
27.5
通讯作者：
Xia, Gui-Xian
中科院分区：
文献类型：
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作者：
Yang, Chun-Lin;Liang, Shan;Xia, Gui-Xian
在本研究中，我们从高地棉中鉴定了一个与防御相关的主要胶乳蛋白（MLP）（命名为GhMLP 28），并研究了其功能机制。GhMLP 28转录本普遍存在于棉花植物中，在根中具有较高的积累。GhMLP 28基因的表达诱导大丽轮枝菌接种，并响应防御信号分子，包括乙烯，茉莉酸，水杨酸。通过病毒诱导的基因沉默敲低GhMLP 28表达导致棉花植株对大丽轮枝菌感染的易感性增加，而在烟草中异位过表达GhMLP 28提高了转基因植株的抗病性。进一步分析表明，GhMLP 28与棉花乙烯反应因子6（GhERF 6）相互作用，促进GhERF 6与GCC-box元件的结合。瞬时表达实验表明，GhMLP 28增强了GhERF 6转录因子的活性，从而导致部分GCC盒基因的表达增强。GhMLP 28蛋白位于细胞核和细胞质中，其核分布依赖于GhERF 6的存在。总的来说，这些结果表明，GhMLP 28作为一个积极的调节GhERF 6，和两种蛋白质的协同作用可能有助于保护棉花植物免受V. dahliae感染。
In this study, we identified a defense-related major latex protein (MLP) from upland cotton (designated GhMLP28) and investigated its functional mechanism. GhMLP28 transcripts were ubiquitously present in cotton plants, with higher accumulation in the root. Expression of the GhMLP28 gene was induced by Verticillium dahliae inoculation and was responsive to defense signaling molecules, including ethylene, jasmonic acid, and salicylic acid. Knockdown of GhMLP28 expression by virus-induced gene silencing resulted in increased susceptibility of cotton plants to V. dahliae infection, while ectopic overexpression of GhMLP28 in tobacco improved the disease tolerance of the transgenic plants. Further analysis revealed that GhMLP28 interacted with cotton ethylene response factor 6 (GhERF6) and facilitated the binding of GhERF6 to GCC-box element. Transient expression assay demonstrated that GhMLP28 enhanced the transcription factor activity of GhERF6, which led to the augmented expression of some GCC-box genes. GhMLP28 proteins were located in both the nucleus and cytoplasm and their nuclear distribution was dependent on the presence of GhERF6. Collectively, these results demonstrate that GhMLP28 acts as a positive regulator of GhERF6, and synergetic actions of the two proteins may contribute substantially to protection against V. dahliae infection in cotton plants.