Gibberellins Promote Flowering of Arabidopsis by Activating the LEAFY Promoter

作者：Miguel Á. Blázquez, Roland Green, Ove R Nilsson, Michael R. Sussman, Detlef Weigel · 发表于：The Plant Cell · 年份：1998 · DOI：10.1105/tpc.10.5.791 · 被引用次数：608 · 研究领域：Plant Molecular Biology Research、Plant Reproductive Biology、Photosynthetic Processes and Mechanisms

The gibberellin class of plant hormones has been implicated in the control of flowering in several species. In Arabidopsis, severe reduction of endogenous gibberellins delays flowering in long days and prevents flowering in short days. We have investigated how the differential effects of gibberellins on flowering correlate with expression of LEAFY, a floral meristem identity gene. We have found that the failure of gibberellin-deficient ga1-3 mutants to flower in short days was paralleled by the absence of LEAFY promoter induction. A causal connection between these two events was confirmed by the ability of a constitutively expressed LEAFY transgene to restore flowering to ga1-3 mutants in short days. In contrast to short days, impairment of gibberellin biosynthesis caused merely a reduction of LEAFY expression when plants were grown in long days or with sucrose in the dark. As a first step toward identifying other small molecules that might regulate flowering, we have developed a rapid in vitro assay for LEAFY promoter activity.