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Updated: May 13, 2026

Identification of the Genes Involved in Stomatal Development via Epidermal Phenotype Scoring
Published on: January 20, 2023
KNOX2 genes regulate the haploid-to-diploid morphological transition in land plants
Keiko Sakakibara1, Sayuri Ando, Hoichong Karen Yip
1Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, Japan. bara@hiroshima-u.ac.jp
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.
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