title: Sequential regulation of gibberellin, brassinosteroid, and jasmonic acid biosynthesis occurs in rice coleoptiles to control the transcript levels of anti-microbial thionin genes.
abstract: Transcripts of thionin genes encoding antimicrobial peptides were present at a high level in rice coleoptiles just after germination, and decreased to an undetectable level after about 3 d, but this decline was suppressed by co-treatment with gibberellic acid (GA(3)) and brassinolide (BL). The temporal expression patterns of key enzyme genes for the biosyntheses of gibberellins (GAs) and brassinosteroids (BRs) were correlated with the fluctuation of thionin mRNAs. Jasmonic acid (JA) replaced the effect of GA3 and BL, and its change in endogenous level was parallel to that of the thionin genes. These results strongly suggest that thionin gene expression was positively regulated by JA, whose endogenous level was synergistically regulated by GAs and BRs. In contrast, thionin gene expression in etiolated seedlings remained high while the endogenous level of JA was low, suggesting the presence of another signaling pathway in the dark to maintain the thionin level.
authors.affiliation: Department of Applied Biological Chemistry, The University of Tokyo, Japan.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kitanaga
authors.forename: Cui
authors.initials: C
authors.lastname: Jian
authors.forename: Morifumi
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Junshi
authors.initials: J
authors.lastname: Yazaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Kishimoto
authors.forename: Shoshi
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Hidemitsu
authors.initials: H
authors.lastname: Nakamura
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Tadao
authors.initials: T
authors.lastname: Asami
authors.forename: Shigeo
authors.initials: S
authors.lastname: Yoshida
authors.forename: Isomaro
authors.initials: I
authors.lastname: Yamaguchi
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000235:genetics*; D060406:Brassinosteroids; D002777:Cholestanols / Q000378:metabolism* / Q000494:pharmacology; D003517:Cyclopentanes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D005875:Gibberellins / Q000096:biosynthesis* / Q000494:pharmacology; D012275:Oryza; D054883:Oxylipins; D010940:Plant Proteins / Q000235:genetics*; D012333:RNA, Messenger; D036226:Seedlings / Q000235:genetics; D013260:Steroids, Heterocyclic / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D023181:Antimicrobial Cationic Peptides; D060406:Brassinosteroids; D002777:Cholestanols; D003517:Cyclopentanes; D005875:Gibberellins; D054883:Oxylipins; D010940:Plant Proteins; D012333:RNA, Messenger; D013260:Steroids, Heterocyclic; C011006:jasmonic acid; C007842:gibberellic acid; C023623:brassinolide