title: Control of seed germination by light-induced histone arginine demethylation activity.
abstract: For optimal survival, various environmental and endogenous factors should be monitored to determine the appropriate timing for seed germination. Light is a major environmental factor affecting seed germination, which is perceived by phytochromes. The light-dependent activation of phytochrome B (PHYB) modulates abscisic acid and gibberellic acid signaling and metabolism. Thus far, several negative regulators of seed germination that act when PHYB is inactive have been reported. However, neither positive regulators of seed germination downstream of PHYB nor a direct mechanism for regulation of the hormone levels has been elucidated. Here, we show that the histone arginine demethylases, JMJ20 and JMJ22, act redundantly as positive regulators of seed germination. When PHYB is inactive, JMJ20/JMJ22 are directly repressed by the zinc-finger protein SOMNUS. However, upon PHYB activation, JMJ20/JMJ22 are derepressed, resulting in increased gibberellic acid levels through the removal of repressive histone arginine methylations at GA3ox1/GA3ox2, which in turn promotes seed germination.
authors.affiliation: School of Biological Sciences, Seoul National University, Seoul 151-747, Korea.
authors.forename: Jung-Nam
authors.initials: JN
authors.lastname: Cho
authors.forename: Jee-Youn
authors.initials: JY
authors.lastname: Ryu
authors.forename: Young-Min
authors.initials: YM
authors.lastname: Jeong
authors.forename: Jihye
authors.initials: J
authors.lastname: Park
authors.forename: Ji-Joon
authors.initials: JJ
authors.lastname: Song
authors.forename: Richard M
authors.initials: RM
authors.lastname: Amasino
authors.forename: Bosl
authors.initials: B
authors.lastname: Noh
authors.forename: Yoo-Sun
authors.initials: YS
authors.lastname: Noh
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001120:Arginine / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D024202:Electrophoretic Mobility Shift Assay; D018506:Gene Expression Regulation, Plant; D018525:Germination / Q000502:physiology*; D005875:Gibberellins / Q000494:pharmacology; D056466:Histone Demethylases / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008027:Light; D008745:Methylation / Q000528:radiation effects*; D051939:Phytochrome B / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic / Q000235:genetics; D012639:Seeds / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D005875:Gibberellins; D006657:Histones; C533360:SOMNUS protein, Arabidopsis; D051939:Phytochrome B; D001120:Arginine; C007842:gibberellic acid; D056466:Histone Demethylases