| Affiliation: | (1) Research Institute for Biological Sciences, Okayama, Jobo-gun, Kayo-chou, 716-1241 Okayama, Japan;(2) Present address: Graduate School of Agriculture, Kyoto Prefectural University, 1–5 Hangi-Chou, Shimogamo, Sakyo-Ku, 606-8522 Kyoto, Japan;(3) Present address: Faculty of Agriculture, Tottori University, 680-8553 Tottori, Japan;(4) Present address: Research Institute of Biological Resources, National Institute of Advanced Industrial Science and Technology, 062-8517 Sapporo, Japan |
| Abstract: | Eustoma grandiflorumShinn 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 -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.Communicated by K.K. Kamo |
