ROS accumulation and antiviral defence control by microRNA528 in rice
ROS accumulation and antiviral defence control by microRNA528 in rice
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水稻中ROS的积累和microRNA528的抗病毒防御控制
DOI：
10.1038/nplants.2016.203
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发表时间：
2017-01-01
期刊：
影响因子：
18
通讯作者：
Li, Yi
中科院分区：
文献类型：
--
作者：
Wu, Jianguo;Yang, Rongxin;Li, Yi
MicroRNAs （miRNAs）是植物与病原体相互作用的关键调控因子。调节miRNA功能已成为产生病毒抗性性状的新策略（1-5）。然而，参与抗病毒防御的mirna及其潜在机制在很大程度上仍然难以捉摸。我们之前证明了Argonaute （AGO）蛋白的隔离在调节抗病毒防御途径中的miRNA功能方面起着重要作用(6)。在这里，我们揭示了切割缺陷的AGO18复合物在病毒感染时隔离microRNA528 （miR528）。我们发现miR528通过切割l -抗坏血酸氧化酶（AO）信使RNA负调控水稻病毒抗性，从而减少AO介导的活性氧积累。病毒感染后，miR528优先与AGO18相关，导致AO活性升高，基础活性氧积累增加，抗病毒防御增强。我们的发现揭示了一种机制，通过抑制负调控病毒耐药性的miRNA来增强抗病毒防御。这种机制可以被操纵来培育出抗病毒作物。
MicroRNAs (miRNAs) are key regulators of plant-pathogen interactions. Modulating miRNA function has emerged as a new strategy to produce virus resistance traits(1-5). However, the miRNAs involved in antiviral defence and the underlying mechanisms remain largely elusive. We previously demonstrated that sequestration by Argonaute (AGO) proteins plays an important role in regulating miRNA function in antiviral defence pathways(6). Here we reveal that cleavage-defective AGO18 complexes sequester microRNA528 (miR528) upon viral infection. We show that miR528 negatively regulates viral resistance in rice by cleaving L-ascorbate oxidase (AO) messenger RNA, thereby reducing AO-mediated accumulation of reactive oxygen species. Upon viral infection, miR528 becomes preferentially associated with AGO18, leading to elevated AO activity, higher basal reactive oxygen species accumulation and enhanced antiviral defence. Our findings reveal a mechanism in which antiviral defence is boosted through suppression of an miRNA that negatively regulates viral resistance. This mechanism could be manipulated to engineer virus-resistant crop plants.