Osa-miR164a targets OsNAC60 and negatively regulates rice immunity against the blast fungus Magnaporthe oryzae

Zhaoyun Wang; Yeqiang Xia; Siyuan Lin; Yanru Wang; Baohuan Guo; Xiaoning Song; Shaochen Ding; Liyu Zheng; Ruiying Feng; Shulin Chen; Yalin Bao; Cong Sheng; Xin Zhang; Jianguo Wu; Dongdong Niu; Hailing Jin; Hongwei Zhao

doi:10.1111/tpj.13972

Osa-miR164a targets OsNAC60 and negatively regulates rice immunity against the blast fungus Magnaporthe oryzae

Plant J. 2018 May 18. doi: 10.1111/tpj.13972. Online ahead of print.

Authors

Zhaoyun Wang^{1

2}, Yeqiang Xia^{1

2}, Siyuan Lin^{1

2}, Yanru Wang^{1

2}, Baohuan Guo^{1

2}, Xiaoning Song^{1

2}, Shaochen Ding^{1

2}, Liyu Zheng^{1

2}, Ruiying Feng^{1

2}, Shulin Chen^{1

2}, Yalin Bao^{1

2}, Cong Sheng^{1

2}, Xin Zhang^{1

2}, Jianguo Wu³, Dongdong Niu^{1

2}, Hailing Jin⁴, Hongwei Zhao^{1

2}

Affiliations

¹ Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
² The Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing, Jiangsu, 210095, China.
³ Fujian Province Key Laboratory of Plant Virology, Institute of Plant Virology, Fujian Agriculture and Forestry University, Fuzhou, China.
⁴ Department of Plant Pathology and Microbiology, University of California, Riverside, CA, 92521, USA.

PMID: 29775494
DOI: 10.1111/tpj.13972

Abstract

Exploring the regulatory mechanism played by endogenous rice miRNAs in defense responses against the blast disease is of great significance in both resistant variety breeding and disease control management. We identified rice defense-related miRNAs by comparing rice miRNA expression patterns before and after Magnaporthe oryzae strain Guy11 infection. We discovered that osa-miR164a expression reduced upon Guy11 infection at both early and late stages, which was perfectly associated with the induced expression of its target gene, OsNAC60. OsNAC60 encodes a transcription factor, over-expression of which enhanced defense responses, such as increased programmed cell death, greater ion leakage, more reactive oxygen species accumulation and callose deposition, and upregulation of defense-related genes. By using transgenic rice over-expressing osa-miR164a, and a transposon insertion mutant of OsNAC60, we showed that when the miR164a/OsNAC60 regulatory module was dysfunctional, rice developed significant susceptibility to Guy11 infection. The co-expression of OsNAC60 and osa-miR164a abolished the OsNAC60 activity, but not its synonymous mutant. We further validated that this regulatory module is conserved in plant resistance to multiple plant diseases, such as the rice sheath blight, tomato late blight, and soybean root and stem rot diseases. Our results demonstrate that the miR164a/OsNAC60 regulatory module manipulates rice defense responses to M. oryzae infection. This discovery is of great potential for resistant variety breeding and disease control to a broad spectrum of pathogens in the future.

Keywords: NAC transcription factor; defense; microRNA; rice blast; silencing.