title: Evolution of the class III HD-Zip gene family in land plants.
abstract: Arabidopsis class III homeodomain-leucine zipper (HD-Zip III) proteins play overlapping, distinct, and antagonistic roles in key aspects of development that have evolved during land plant evolution. To better understand this gene family's role in plant evolution and development as well as to address broader questions of how duplicated genes functionally diversify, we investigated the evolutionary history of this gene family. Phylogenetic analyses including homologs from diverse land plants indicate that a gene duplication event before the angiosperm--gymnosperm split gave rise to two gene lineages that diversified during angiosperm plant radiation. Heterologous expression of an HD-Zip III gene from the nonvascular plant moss within the Arabidopsis HD-zip III revoluta mutant modified but did not complement the phenotype. Comparison of the expression domains of flowering and nonflowering plant homologs indicate an ancestral role in vascular development and organ initiation but not in specifying organ polarity, a prominent role for angiosperm homologs.
authors.affiliation: Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI 48109-1048, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Prigge
authors.forename: Steven E
authors.initials: SE
authors.lastname: Clark
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D018398:Homeodomain Proteins / Q000145:classification / Q000235:genetics*; D016350:Leucine Zippers / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family
chemical_list: D029681:Arabidopsis Proteins; C493946:HD-Zip protein, Arabidopsis; D018398:Homeodomain Proteins