title: Two rice GRAS family genes responsive to N -acetylchitooligosaccharide elicitor are induced by phytoactive gibberellins: evidence for cross-talk between elicitor and gibberellin signaling in rice cells.
abstract: In this study, we present data showing that two members of the GRAS family of genes from rice, CIGR1 and CIGR2 (chitin-inducible gibberellin-responsive), inducible by the potent elicitor N -acetylchitooligosaccharide (GN), are rapidly induced by exogenous gibberellins. The pattern of mRNA accumulation was dependent on the dose and biological activity of the gibberellins, suggesting that the induction of the genes by gibberellin is mediated by a biological receptor capable of specific recognition and signal transduction upon perception of the phytoactive compounds. Further pharmacological analysis revealed that the CIGR1 and CIGR2 mRNA accumulation by treatment with gibberellin is dependent upon protein phosphorylation/dephosphorylation events. In rice calli derived from slender rice 1, a constitutive gibberellin-responsive mutant, or d1, a mutant deficient in the alpha -subunit of the heterotrimeric G-protein, CIGR1 and CIGR2 were induced by a GN elicitor, yet not by gibberellin. Neither gibberellin nor GN showed related activities in defense or development, respectively. These results strongly suggested that the signal transduction cascade from gibberellin is independent of that from GN, and further implied that CIGR1 and CIGR2 have dual, distinct roles in defense and development.
authors.affiliation: Department of Biochemistry, National Institute of Agrobiological Sciences, 2-1-2, Kannondai, Tsukuba 305-8602, Japan.
authors.forename: R Bradley
authors.initials: RB
authors.lastname: Day
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tanabe
authors.forename: Masaji
authors.initials: M
authors.lastname: Koshioka
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Mitsui
authors.forename: Hironori
authors.initials: H
authors.lastname: Itoh
authors.forename: Miyako
authors.initials: M
authors.lastname: Ueguchi-Tanaka
authors.forename: Makoto
authors.initials: M
authors.lastname: Matsuoka
authors.forename: Hanae
authors.initials: H
authors.lastname: Kaku
authors.forename: Naoto
authors.initials: N
authors.lastname: Shibuya
authors.forename: Eiichi
authors.initials: E
authors.lastname: Minami
mesh_terms: D015152:Blotting, Northern; D002686:Chitin / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005875:Gibberellins / Q000494:pharmacology*; D017403:In Situ Hybridization; D009154:Mutation; D009844:Oligosaccharides / Q000494:pharmacology*; D012275:Oryza / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D005875:Gibberellins; D009844:Oligosaccharides; D010940:Plant Proteins; D012333:RNA, Messenger; D002686:Chitin; C082723:N-acetylchitooctaose