title: The Gibberellin perception system evolved to regulate a pre-existing GAMYB-mediated             system during land plant evolution.
abstract: Gibberellin (GA) controls pollen development in flowering plants via the GAMYB                 transcription factor. Here we show that GAMYB is conserved in Selaginella                     moellendorffii (lycophyte) and Physcomitrella patens (moss), although                 the former contains the GA signalling pathway, the latter does not. In the                 lycophyte, GA treatment promotes the outer wall development on microspores, whereas                 treatment with GA biosynthesis inhibitors disturbs its development. Contrary, in the                 moss, GAMYB homologue knockouts also produce abnormal spores that resemble                     Selaginella microspores treated with GA biosynthesis inhibitors and                 pollen grains of rice gamyb mutant. Moreover, the knockouts fail to develop                 male organs, instead ectopically forming female organs. Thus, before the                 establishment of the GA signalling pathway, basal land plants, including mosses,                 contained a GAMYB-based system for spore and sexual organ development. Subsequently,                 during the evolution from mosses to basal vascular plants including lycophytes, GA                 signalling might have merged to regulate this pre-existing GAMYB-based system.
authors: Bioscience and Biotechnology Center, Nagoya University, Nagoya 464-8601, Japan. aya.koichiro@e.mbox.nagoya-u.ac.jp
authors: Koichiro
authors: K
authors: Aya
authors: Yuji
authors: Y
authors: Hiwatashi
authors: Mikiko
authors: M
authors: Kojima
authors: Hitoshi
authors: H
authors: Sakakibara
authors: Miyako
authors: M
authors: Ueguchi-Tanaka
authors: Mitsuyasu
authors: M
authors: Hasebe
authors: Makoto
authors: M
authors: Matsuoka
mesh_terms: D005075:Biological Evolution; D019669:Embryophyta / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000502:physiology; D005875:Gibberellins / Q000378:metabolism*; D010940:Plant Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D005875:Gibberellins; D010940:Plant Proteins