title: Identification of a novel microRNA (miRNA) from rice that targets an alternatively spliced transcript of the Nramp6 (Natural resistance-associated macrophage protein 6) gene involved in pathogen resistance.
abstract: Plants have evolved efficient defence mechanisms to defend themselves from pathogen attack. Although many studies have focused on the transcriptional regulation of defence responses, less is known about the involvement of microRNAs (miRNAs) as post-transcriptional regulators of gene expression in plant immunity. This work investigates miRNAs that are regulated by elicitors from the blast fungus Magnaporthe oryzae in rice (Oryza sativa). Small RNA libraries were constructed from rice tissues and subjected to high-throughput sequencing for the identification of elicitor-responsive miRNAs. Target gene expression was examined by microarray analysis. Transgenic lines were used for the analysis of miRNA functioning in disease resistance. Elicitor treatment is accompanied by dynamic alterations in the expression of a significant number of miRNAs, including new members of annotated miRNAs. Novel miRNAs from rice are proposed. We report a new rice miRNA, osa-miR7695, which negatively regulates an alternatively spliced transcript of OsNramp6 (Natural resistance-associated macrophage protein 6). This novel miRNA experienced natural and domestication selection events during evolution, and its overexpression in rice confers pathogen resistance. This study highlights an miRNA-mediated regulation of OsNramp6 in disease resistance, whilst illustrating the existence of a novel regulatory network that integrates miRNA function and mRNA processing in plant immunity.
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain.|Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: Sonia
authors.initials: S
authors.lastname: Campo
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain.
authors.forename: Cristina
authors.initials: C
authors.lastname: Peris-Peris
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain.
authors.forename: Christelle
authors.initials: C
authors.lastname: Siré
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain.
authors.forename: Ana Beatriz
authors.initials: AB
authors.lastname: Moreno
authors.affiliation: Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: Livia
authors.initials: L
authors.lastname: Donaire
authors.affiliation: Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), UPF, 08003, Barcelona, Spain.
authors.forename: Matthias
authors.initials: M
authors.lastname: Zytnicki
authors.affiliation: Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), UPF, 08003, Barcelona, Spain.
authors.forename: Cedric
authors.initials: C
authors.lastname: Notredame
authors.affiliation: Department of Environmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040, Madrid, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Llave
authors.affiliation: Centre for Research in Agricultural Genomics (CRAG), CSIC-IRTA-UAB-UB, Edifici CRAG, Campus UAB, Bellaterra (Cerdanyola del Vallés), Barcelona, 08193, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: San Segundo
mesh_terms: D017398:Alternative Splicing; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000382:microbiology*; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D018515:Plant Leaves / Q000235:genetics; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics; D030821:Plants, Genetically Modified; D018749:RNA, Plant / Q000235:genetics; D015203:Reproducibility of Results; D013045:Species Specificity; D014026:Nicotiana / Q000235:genetics
chemical_list: D035683:MicroRNAs; D010940:Plant Proteins; D018749:RNA, Plant