title: Genome-wide characterization of the HD-ZIP IV transcription factor family in maize: preferential expression in the epidermis.
abstract: Transcription factors of the plant-specific homeodomain leucine zipper IV (HD-ZIP IV) family have been found from moss to higher plants, and several family members have been associated with epidermis-related expression and/or function. In maize (Zea mays), four of the five characterized HD-ZIP IV family members are expressed specifically in the epidermis, one contributes to trichome development, and target genes of another one are involved in cuticle biosynthesis. Assessing the phylogeny, synteny, gene structure, expression, and regulation of the entire family in maize, 12 novel ZmHDZIV genes were identified in the recently sequenced maize genome. Among the 17 genes, eight form homeologous pairs duplicated after the split of maize and sorghum (Sorghum bicolor), whereas a fifth duplication is shared with sorghum. All 17 ZmHDZIV genes appear to be derived from a basic module containing seven introns in the coding region. With one possible exception, all 17 ZmHDZIV genes are expressed and show preferential expression in immature reproductive organs. Fourteen of 15 ZmHDZIV genes with detectable expression in laser-dissected tissues exhibit a moderate to very strong expression preference for the epidermis, suggesting that at least in maize, the majority of HD-ZIP IV family members may have epidermis-related functions. Thirteen ZmHDZIV genes carry conserved motifs of 19 and 21 nucleotides in their 3' untranslated region. The strong evolutionary conservation and the size of the conserved motifs in the 3' untranslated region suggest that the expression of HD-ZIP IV genes may be regulated by small RNAs.
authors.affiliation: Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, Unité Reproduction et Développement des Plantes, F-69364 Lyon, France.
authors.forename: Marie
authors.initials: M
authors.lastname: Javelle
authors.forename: Catherine
authors.initials: C
authors.lastname: Klein-Cosson
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vernoud
authors.forename: Véronique
authors.initials: V
authors.lastname: Boltz
authors.forename: Chris
authors.initials: C
authors.lastname: Maher
authors.forename: Marja
authors.initials: M
authors.lastname: Timmermans
authors.forename: Nathalie
authors.initials: N
authors.lastname: Depège-Fargeix
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rogowsky
mesh_terms: D020413:3' Untranslated Regions; D001483:Base Sequence; D017124:Conserved Sequence; D005091:Exons; D018506:Gene Expression Regulation, Plant; D018745:Genome, Plant; D007438:Introns; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D019441:Plant Epidermis / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D003313:Zea mays / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D010940:Plant Proteins; D014157:Transcription Factors