title: WOX gene phylogeny in Poaceae: a comparative approach addressing leaf and embryo development.
abstract: The phylogeny based on the homeodomain (HD) amino acid sequence of the WOX (WUSCHEL-related homeobox gene family) was established in the 3 major radiations of the Poaceae family: Pooideae (Brachypodium distachyon), Bambusoideae (Oryza sativa), and Panicoideae (Zea mays). The genomes of all 3 grasses contain an ancient duplication in the WOX3 branch, and the cellular expression patterns in maize and rice indicate subfunctionalization of paralogues during leaf development, which may relate to the architecture of the grass leaf and the encircling of the stem. The use of maize WOX gene family members as molecular markers in maize embryo development for the first time allowed us to visualize cellular decisions in the maize proembryo, including specification of the shoot/root axis at an oblique angle to the apical-basal polarity of the zygote. All molecular marker data are compatible with the conclusion that the embryonic shoot/root axis comprises a discrete domain from early proembryo stages onward. Novel cell fates of the shoot and the root are acquired within this distinct morphogenic axis domain, which elongates and thus separates the shoot apical meristem and root apical meristem (RAM) anlagen in the maize embryo.
authors.affiliation: Institut für Entwicklungsbiologie, Universität zu Köln, Köln, Germany.
authors.forename: Judith
authors.initials: J
authors.lastname: Nardmann
authors.forename: Roman
authors.initials: R
authors.lastname: Zimmermann
authors.forename: Diego
authors.initials: D
authors.lastname: Durantini
authors.forename: Erhard
authors.initials: E
authors.lastname: Kranz
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Werr
mesh_terms: D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics*; D017403:In Situ Hybridization; D018519:Meristem / Q000235:genetics / Q000254:growth & development; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics / Q000254:growth & development; D010802:Phylogeny; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D010940:Plant Proteins / Q000235:genetics*; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D006109:Poaceae / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012639:Seeds / Q000235:genetics / Q000254:growth & development; D017422:Sequence Analysis, DNA; D003313:Zea mays / Q000235:genetics / Q000254:growth & development
chemical_list: D018398:Homeodomain Proteins; D010940:Plant Proteins