title: Thermoinduction of genes encoding the enzymes of gibberellin biosynthesis and a putative negative regulator of gibberellin signal transduction in Eustoma grandiflorum.
abstract: Eustoma grandiflorum Shinn requires vernalization for the induction of stem elongation and flowering. To investigate the role of gibberellins (GAs) in vernalization, the expression levels of genes encoding enzymes of GA biosynthesis, copalyl diphosphate synthetase, GA 20-oxidase and GA 3 beta-hydroxylase, were examined using two culitvars that show different responses to vernalization. The three genes were induced in a vernalization- and a cultivar-dependent manner. EgSPY, a putative negative regulator of GA signal transduction, was also induced during the vernalization period. The results suggest that the expression of the genes encoding GAs biosynthesis is regulated by vernalization. We postulate that EgSPY functions as a negative regulator of GA signal transduction during vernalization, inhibiting adventitious shoot elongation during vernalization.
authors.affiliation: Research Institute for Biological Sciences, Okayama, Jobo-gun, Kayo-chou, 716-1241 Okayama, Japan. mino@kpu.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Mino
authors.forename: M
authors.initials: M
authors.lastname: Oka
authors.forename: Y
authors.initials: Y
authors.lastname: Tasaka
authors.forename: M
authors.initials: M
authors.lastname: Iwabuchi
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000096:biosynthesis / Q000235:genetics; D004790:Enzyme Induction; D004798:Enzymes / Q000096:biosynthesis / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D005809:Genes, Regulator / Q000235:genetics* / Q000502:physiology; D029965:Gentianaceae / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D005875:Gibberellins / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology; D006899:Mixed Function Oxygenases / Q000096:biosynthesis / Q000235:genetics; D010940:Plant Proteins; D018520:Plant Shoots / Q000187:drug effects / Q000254:growth & development; D015398:Signal Transduction; D013696:Temperature; D013997:Time Factors
chemical_list: D004798:Enzymes; D005875:Gibberellins; D010940:Plant Proteins; C007842:gibberellic acid; D006899:Mixed Function Oxygenases; C089210:gibberellin, 2-oxoglutarate-oxygen oxidoreductase (20-hydroxylating, oxidizing); C108186:gibberellin 3beta-hydroxylase; D019883:Alkyl and Aryl Transferases; C090963:ent-kaurene synthetase A