Mino M, Oka M, Tasaka Y, Iwabuchi M
Research Institute for Biological Sciences, Okayama, Jobo-gun, Kayo-chou, 716-1241 Okayama, Japan.
Plant Cell Rep. 2003 Sep;22(2):159-65. doi: 10.1007/s00299-003-0672-z. Epub 2003 Jul 23.
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.
洋桔梗需要经过春化处理才能诱导茎伸长和开花。为了研究赤霉素（GAs）在春化过程中的作用，利用两个对春化反应不同的品种，检测了编码GA生物合成酶、柯巴基焦磷酸合酶、GA 20-氧化酶和GA 3β-羟化酶的基因的表达水平。这三个基因的诱导呈春化和品种依赖性。EgSPY是GA信号转导的一个假定负调控因子，在春化期间也被诱导。结果表明，编码GAs生物合成的基因的表达受春化调控。我们推测，EgSPY在春化过程中作为GA信号转导的负调控因子，抑制春化期间不定芽的伸长。
