Osa-miR169 Negatively Regulates Rice Immunity against the Blast Fungus Magnaporthe oryzae.
Osa-miR169 Negatively Regulates Rice Immunity against the Blast Fungus Magnaporthe oryzae.
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Osa-miR169 负调节水稻对稻瘟病菌的免疫力。
DOI：
10.3389/fpls.2017.00002
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发表时间：
2017
影响因子：
5.6
通讯作者：
Wang WM
中科院分区：
文献类型：
--
作者：
Li Y;Zhao SL;Li JL;Hu XH;Wang H;Cao XL;Xu YJ;Zhao ZX;Xiao ZY;Yang N;Fan J;Huang F;Wang WM
miR169是一个保守的microRNA （miRNA）家族，参与植物发育和胁迫诱导反应。然而，miR169如何在水稻免疫中起作用仍不清楚。在这里，我们发现miR169通过抑制核因子Y-A （NF-YA）基因的表达，在水稻对稻瘟病菌的免疫中起负调控作用。受M. oryzae感染后，miR169的积累量在敏感品种中显著增加，而在抗性品种中略有波动。一致地，过表达miR169a的转基因系对不同的m.o ryzae菌株变得超敏感，这与防御相关基因的表达减少和感染部位过氧化氢积累的缺乏有关。因此，其靶基因NF-YA家族成员的表达在转录或翻译水平上被miR169a的过表达下调。相反，过度表达靶拟像海绵一样捕获miR169a导致对m.o ryzae的抗性增强。此外，miR169的三个靶基因在m.o ryzae感染的抗性加入中也出现了差异上调。综上所述，我们的数据表明miR169通过差异抑制其靶基因负向调节水稻对m.o ryzae的免疫，并提供了通过miRNA设计水稻抗稻瘟病的潜力。
miR169 is a conserved microRNA (miRNA) family involved in plant development and stress-induced responses. However, how miR169 functions in rice immunity remains unclear. Here, we show that miR169 acts as a negative regulator in rice immunity against the blast fungus Magnaporthe oryzae by repressing the expression of nuclear factor Y-A (NF-YA) genes. The accumulation of miR169 was significantly increased in a susceptible accession but slightly fluctuated in a resistant accession upon M. oryzae infection. Consistently, the transgenic lines overexpressing miR169a became hyper-susceptible to different M. oryzae strains associated with reduced expression of defense-related genes and lack of hydrogen peroxide accumulation at the infection site. Consequently, the expression of its target genes, the NF-YA family members, was down-regulated by the overexpression of miR169a at either transcriptional or translational level. On the contrary, overexpression of a target mimicry that acts as a sponge to trap miR169a led to enhanced resistance to M. oryzae. In addition, three of miR169’s target genes were also differentially up-regulated in the resistant accession upon M. oryzae infection. Taken together, our data indicate that miR169 negatively regulates rice immunity against M. oryzae by differentially repressing its target genes and provide the potential to engineer rice blast resistance via a miRNA.