title: miR828 and miR858 regulate homoeologous MYB2 gene functions in Arabidopsis trichome and cotton fibre development.
abstract: Although polyploidy is common in plants and some animals, mechanisms for functional divergence between homoeologous genes are poorly understood. MYB2 gene promotes cotton fibre development and is functionally homologous to Arabidopsis GLABROUS1 (GL1) in trichome formation. The most widely cultivated cotton is an allotetraploid (Gossypium hirsutum, AADD) that contains GhMYB2A and GhMYB2D homoeologs. Here we show that GhMYB2D mRNA accumulates more than GhMYB2A during fibre initiation and is targeted by miR828 and miR858, generating trans-acting siRNAs (ta-siRNAs) in the TAS4 family. Overexpressing GhMYB2A but not GhMYB2D complements the gl1 phenotype. Mutating the miR828-binding site or replacing its downstream sequence in GhMYB2D abolishes ta-siRNA production and restores trichome development in gl1 mutants. Moreover, disrupting Dicer-like protein 4 or RDR6, the biogenesis genes for ta-siRNAs, in the gl1 GhMYB2D overexpressors restores trichome development. These data support a unique role for microRNAs in functional divergence between target homoeologous genes that are important for evolution and selection of morphological traits.
authors.affiliation: Institute for Cellular and Molecular Biology and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Xueying
authors.initials: X
authors.lastname: Guan
authors.affiliation: Institute for Cellular and Molecular Biology and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Mingxiong
authors.initials: M
authors.lastname: Pang
authors.affiliation: Institute for Cellular and Molecular Biology and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Gyoungju
authors.initials: G
authors.lastname: Nah
authors.affiliation: Institute for Cellular and Molecular Biology and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Wenxue
authors.initials: W
authors.lastname: Ye
authors.affiliation: Department of Soil and Crop Sciences, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Stelly
authors.affiliation: 1] Institute for Cellular and Molecular Biology and Center for Computational Biology and Bioinformatics, The University of Texas at Austin, Austin, Texas 78712, USA [2] State Key Laboratory of Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Z Jeffrey
authors.initials: ZJ
authors.lastname: Chen
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D001483:Base Sequence; D032561:Cotton Fiber; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D017343:Genes, Plant / Q000235:genetics / Q000502:physiology; D003368:Gossypium / Q000235:genetics / Q000502:physiology*; D035683:MicroRNAs / Q000235:genetics / Q000502:physiology*; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D063245:Plant Development / Q000235:genetics / Q000502:physiology*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D015534:Trans-Activators / Q000235:genetics / Q000502:physiology*; D064201:Trichomes / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; C104175:MYB2 protein, Arabidopsis; D035683:MicroRNAs; C000602912:Mirn828 microRNA, Arabidopsis; C000602913:Mirn858 microRNA, Arabidopsis; D015534:Trans-Activators