title: KNOX2 genes regulate the haploid-to-diploid morphological transition in land plants.
abstract: Unlike animals, land plants undergo an alternation of generations, producing multicellular bodies in both haploid (1n: gametophyte) and diploid (2n: sporophyte) generations. Plant body plans in each generation are regulated by distinct developmental programs initiated at either meiosis or fertilization, respectively. In mosses, the haploid gametophyte generation is dominant, whereas in vascular plants-including ferns, gymnosperms, and angiosperms-the diploid sporophyte generation is dominant. Deletion of the class 2 KNOTTED1-LIKE HOMEOBOX (KNOX2) transcription factors in the moss Physcomitrella patens results in the development of gametophyte bodies from diploid embryos without meiosis. Thus, KNOX2 acts to prevent the haploid-specific body plan from developing in the diploid plant body, indicating a critical role for the evolution of KNOX2 in establishing an alternation of generations in land plants.
authors: Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan. bara@hiroshima-u.ac.jp
authors: Keiko
authors: K
authors: Sakakibara
authors: Sayuri
authors: S
authors: Ando
authors: Hoichong Karen
authors: HK
authors: Yip
authors: Yosuke
authors: Y
authors: Tamada
authors: Yuji
authors: Y
authors: Hiwatashi
authors: Takashi
authors: T
authors: Murata
authors: Hironori
authors: H
authors: Deguchi
authors: Mitsuyasu
authors: M
authors: Hasebe
authors: John L
authors: JL
authors: Bowman
mesh_terms: D019068:Bryopsida / Q000033:anatomy & histology* / Q000235:genetics / Q000254:growth & development*; D004171:Diploidy; D017353:Gene Deletion; D017343:Genes, Plant / Q000502:physiology*; D055993:Germ Cells, Plant / Q000254:growth & development*; D006238:Haploidy; D018398:Homeodomain Proteins / Q000235:genetics / Q000502:physiology*
chemical_list: D018398:Homeodomain Proteins