title: The miR9863 family regulates distinct Mla alleles in barley to attenuate NLR receptor-triggered disease resistance and cell-death signaling.
abstract: Barley (Hordeum vulgare L.) Mla alleles encode coiled-coil (CC), nucleotide binding, leucine-rich repeat (NB-LRR) receptors that trigger isolate-specific immune responses against the powdery mildew fungus, Blumeria graminis f. sp. hordei (Bgh). How Mla or NB-LRR genes in grass species are regulated at post-transcriptional level is not clear. The microRNA family, miR9863, comprises four members that differentially regulate distinct Mla alleles in barley. We show that miR9863 members guide the cleavage of Mla1 transcripts in barley, and block or reduce the accumulation of MLA1 protein in the heterologous Nicotiana benthamiana expression system. Regulation specificity is determined by variation in a unique single-nucleotide-polymorphism (SNP) in mature miR9863 family members and two SNPs in the Mla miR9863-binding site that separates these alleles into three groups. Further, we demonstrate that 22-nt miR9863s trigger the biogenesis of 21-nt phased siRNAs (phasiRNAs) and together these sRNAs form a feed-forward regulation network for repressing the expression of group I Mla alleles. Overexpression of miR9863 members specifically attenuates MLA1, but not MLA10-triggered disease resistance and cell-death signaling. We propose a key role of the miR9863 family in dampening immune response signaling triggered by a group of MLA immune receptors in barley.
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Centre for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Centre for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Xiliu
authors.initials: X
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Centre for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Da
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Plant Pathology & Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Weihui
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Plant Pathology & Microbiology, Center for Plant Responses to Environmental Stresses, Iowa State University, Ames, Iowa, United States of America; Corn Insects and Crop Genetics Research, USDA-Agricultural Research Service, Iowa State University, Ames, Iowa, United States of America.
authors.forename: Roger
authors.initials: R
authors.lastname: Wise
authors.affiliation: State Key Laboratory of Plant Cell and Chromosome Engineering, Centre for Molecular Agrobiology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China.
authors.forename: Qian-Hua
authors.initials: QH
authors.lastname: Shen
mesh_terms: D000483:Alleles; D001203:Ascomycota; D001483:Base Sequence; D016923:Cell Death; D060467:Disease Resistance; D063185:Epigenetic Repression; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D001467:Hordeum / Q000235:genetics* / Q000382:microbiology; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010935:Plant Diseases / Q000382:microbiology; D057865:Plant Immunity / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic; D014177:Translations; D014908:Triticum / Q000235:genetics
chemical_list: C433105:MLA1 protein, Hordeum vulgare; D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant; D034741:RNA, Small Interfering