title: Repression of microRNA biogenesis by silencing of OsDCL1 activates the basal resistance to Magnaporthe oryzae in rice.
abstract: The RNaseIII enzyme Dicer-like 1 (DCL1) processes the microRNA biogenesis and plays a determinant role in plant development. In this study, we reported the function of OsDCL1 in the immunity to rice blast, the devastating disease caused by the fungal pathogen, Magnaporthe oryzae. Expression profiling demonstrated that different OsDCLs responded dynamically and OsDCL1 reduced its expression upon the challenge of rice blast pathogen. In contrast, miR162a predicted to target OsDCL1 increased its expression, implying a negative feedback loop between OsDCL1 and miR162a in rice. In addition to developmental defects, the OsDCL1-silencing mutants showed enhanced resistance to virulent rice blast strains in a non-race specific manner. Accumulation of hydrogen peroxide and cell death were observed in the contact cells with infectious hyphae, revealing that silencing of OsDCL1 activated cellular defense responses. In OsDCL1 RNAi lines, 12 differentially expressed miRNAs were identified, of which 5 and 7 were down- and up-regulated, respectively, indicating that miRNAs responded dynamically in the interaction between rice and rice blast. Moreover, silencing of OsDCL1 activated the constitutive expression of defense related genes. Taken together, our results indicate that rice is capable of activating basal resistance against rice blast by perturbing OsDCL1-dependent miRNA biogenesis pathway.
authors.affiliation: State Key Laboratory of Rice Biology and Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors.forename: Muxing
authors.initials: M
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Rice Biology and Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China; State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Mingzhi
authors.initials: M
authors.lastname: Tang
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Rice Biology and Key Laboratory of Chinese Ministry of Agriculture for Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou 310029, China.
authors.forename: Dianxing
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Plant Pathology, College of Plant Protection, Nanjing Agricultural University, and Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing 210095, China.
authors.forename: Zhengguang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China; International Rice Research Institute, DAPO Box 7777, Metro Manila 1301, Philippines. Electronic address: b.zhou@irri.org.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhou
mesh_terms: D060467:Disease Resistance; D018506:Gene Expression Regulation, Plant; D020082:Magnaporthe / Q000472:pathogenicity*; D035683:MicroRNAs / Q000235:genetics*; D012275:Oryza / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D010935:Plant Diseases / Q000276:immunology*; D018515:Plant Leaves / Q000235:genetics / Q000502:physiology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000502:physiology; D030821:Plants, Genetically Modified; D034622:RNA Interference; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D036226:Seedlings / Q000235:genetics / Q000502:physiology; D015854:Up-Regulation
chemical_list: D035683:MicroRNAs; D010940:Plant Proteins; D043244:Ribonuclease III
keywords: Basal resistance; OsDCL1; PR gene; Rice; Rice blast; miRNA