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[優(yōu)秀文章推薦] 李傳友研究組解析茉莉酸調(diào)控植物免疫的轉(zhuǎn)錄重編程 已有1人參與
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![[優(yōu)秀文章推薦] 李傳友研究組解析茉莉酸調(diào)控植物免疫的轉(zhuǎn)錄重編程]()
茉莉酸是來源于不飽和脂肪酸的植物免疫激素。其生物合成途徑和化學(xué)結(jié)構(gòu)與高等動物中的免疫激素前列腺素有極高的類似性。對應(yīng)于機(jī)械傷害、咀嚼式昆蟲和死體營養(yǎng)型病原菌的侵害,植物激活茉莉酸信號通路,啟動并級聯(lián)放大茉莉酸介導(dǎo)的轉(zhuǎn)錄重編程,從而產(chǎn)生有效的防御反應(yīng)。但目前對茉莉酸激活植物免疫轉(zhuǎn)錄重編程的機(jī)理所知甚少。
中國科學(xué)院遺傳與發(fā)育生物學(xué)研究所李傳友研究組長期以番茄為模式研究茉莉酸調(diào)控植物免疫的分子機(jī)理。該研究組最近的研究發(fā)現(xiàn),茉莉酸信號通路的核心轉(zhuǎn)錄因子MYC2通過正向調(diào)控機(jī)械損傷相關(guān)基因及病程相關(guān)基因等與抗病抗蟲密切相關(guān)的基因的表達(dá)實(shí)現(xiàn)植物對病蟲侵害的有效防御。利用染色質(zhì)免疫共沉淀--測序(ChIP-Seq)與全基因組表達(dá)譜--測序(RNA-Seq)相結(jié)合的手段,李傳友研究組在番茄全基因組范圍內(nèi)確定了一系列MYC2直接結(jié)合的靶標(biāo)基因。令人感興趣的是,李傳友研究組發(fā)現(xiàn)MYC2直接結(jié)合的靶標(biāo)基因中富含轉(zhuǎn)錄因子基因,表明MYC2是茉莉酸信號通路中高層級的轉(zhuǎn)錄調(diào)控元件。進(jìn)一步研究表明MYC2與其直接結(jié)合的次級轉(zhuǎn)錄因子形成一系列的轉(zhuǎn)錄級聯(lián)調(diào)控模塊(transcription module)。這些轉(zhuǎn)錄級聯(lián)調(diào)控模塊在免疫轉(zhuǎn)錄重編程的激活和級聯(lián)放大中起至關(guān)重要的作用。這一發(fā)現(xiàn)對于人們深入理解茉莉酸調(diào)控植物抗病抗蟲的機(jī)理具有重要意義,并為番茄抗病抗蟲分子育種提供了重要的理論指導(dǎo)。
該研究結(jié)果已于2017年7月21日在線發(fā)表于The Plant Cell (DOI:10.1105/tpc.16.00953)。李傳友研究組的杜敏敏博士和山東農(nóng)業(yè)大學(xué)的趙久海教授是該論文的共同第一作者。該研究得到中國科學(xué)院戰(zhàn)略性先導(dǎo)專項(xiàng)、科技部、農(nóng)業(yè)部和國家自然科學(xué)基金委的資助。
The hormone jasmonate (JA), which functions in plant immunity, regulates resistance to pathogen infection and insect attack through triggering genome-wide transcriptional reprogramming in plants. We show that the basic helix-loop-helix transcription factor (TF) MYC2 in tomato (Solanum lycopersicum) acts downstream of the JA receptor to orchestrate JA-mediated activation of both the wounding and pathogen responses. Using chromatin immunoprecipitation sequencing (ChIP-seq) coupled with RNA sequencing (RNA-seq) assays, we identified 655 MYC2-targeted JA-responsive genes. These genes are highly enriched in Gene Ontology categories related to TFs and the early response to JA, indicating that MYC2 functions at a high hierarchical level to regulate JA-mediated gene transcription. We also identified a group of MYC2-targeted TFs (MTFs) that may directly regulate the JA-induced transcription of late defense genes. Our findings suggest that MYC2 and its downstream MTFs form a hierarchical transcriptional cascade during JA-mediated plant immunity that initiates and amplifies transcriptional output. As proof of concept, we showed that during plant resistance to the necrotrophic pathogen Botrytis cinerea, MYC2 and the MTF JA2-Like (JA2L) form a transcription module that preferentially regulates wounding-responsive genes, whereas MYC2 and the MTF ETHYLENE RESPONSE FACTOR.C3 (ERF.C3) form a transcription module that preferentially regulates pathogen-responsive genes. |
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