Chen Jin-Feng, Zhao Zhi-Xue, Li Yan, Li Ting-Ting, Zhu Yong, Yang Xue-Mei, Zhou Shi-Xin, Wang He, Zhao Ji-Qun, Pu Mei, Feng Hui, Fan Jing, Zhang Ji-Wei, Huang Yan-Yan, Wang Wen-Ming
Rice Research Institute and Key Lab for Major Crop Diseases, Sichuan Agricultural University, Chengdu, 611130, China.
Rice (N Y). 2021 Mar 6;14(1):26. doi: 10.1186/s12284-021-00469-w.
Rice blast caused by Magnaporthe oryzae is one of the most destructive diseases of rice. An increasing number of microRNAs (miRNAs) have been reported to fine-tune rice immunity against M. oryzae and coordinate with growth and development.
Here, we showed that rice microRNA159a (Osa-miR159a) played a positive role in rice resistance to M. oryzae. The expression of Osa-miR159a was suppressed in a susceptible accession at 12, 24, and 48 h post-inoculation (hpi); it was upregulated in a resistant accession of M. oryzae at 24 hpi. The transgenic rice lines overexpressing Osa-miR159a were highly resistant to M. oryzae. In contrast, the transgenic lines expressing a short tandem target mimic (STTM) to block Osa-miR159a showed enhanced susceptibility. Knockout mutations of the target genes of Osa-miR159a, including OsGAMYB, OsGAMYBL, and OsZF, led to resistance to M. oryzae. Alteration of the expression of Osa-miR159a impacted yield traits including pollen and grain development.
Our results indicated that Osa-miR159a positively regulated rice immunity against M. oryzae by downregulating its target genes. Proper expression of Osa-miR159a was critical for coordinating rice blast resistance with grain development.
由稻瘟病菌引起的稻瘟病是水稻最具毁灭性的病害之一。越来越多的微小RNA（miRNA）被报道可微调水稻对稻瘟病菌的免疫反应，并与生长发育相互协调。
在此，我们表明水稻微小RNA159a（Osa-miR159a）在水稻对稻瘟病菌的抗性中发挥积极作用。在感病品种中，接种后12、24和48小时（hpi）时Osa-miR159a的表达受到抑制；在抗病品种中，接种24 hpi时其表达上调。过表达Osa-miR159a的转基因水稻株系对稻瘟病菌具有高度抗性。相反，表达短串联靶标模拟物（STTM）以阻断Osa-miR159a的转基因株系表现出增强的感病性。Osa-miR159a靶基因（包括OsGAMYB、OsGAMYBL和OsZF）的敲除突变导致对稻瘟病菌的抗性。Osa-miR159a表达的改变影响了包括花粉和籽粒发育在内的产量性状。
我们的结果表明，Osa-miR159a通过下调其靶基因来正向调控水稻对稻瘟病菌的免疫反应。Osa-miR159a的适当表达对于协调水稻抗稻瘟病能力与籽粒发育至关重要。
