Abstract

Flower initiation in Arabidopsis thaliana under noninductive short-day conditions is dependent on the biosynthesis of the plant hormone gibberellin ( GA). This dependency can be explained, at least partly, by GA regulation of the flower meristem identity gene LEAFY ( LFY) and the flowering time gene SUPPRESSOR OF CONSTANS1. Although it is well established that GA(4) is the active GA in the regulation of Arabidopsis shoot elongation, the identity of the GA responsible for the regulation of Arabidopsis flowering has not been established. Through a combination of GA quantifications and sensitivity assays, we show that GA(4) is the active GA in the regulation of LFY transcription and Arabidopsis flowering time under short-day conditions. The levels of GA(4) and sucrose increase dramatically in the shoot apex shortly before floral initiation, and the regulation of genes involved in GA metabolism suggests that this increase is possibly due to transport of GAs and sucrose from outside sources to the shoot apex. Our results demonstrate that in the dicot Arabidopsis, in contrast with the monocot Lolium temulentum, GA(4) is the active GA in the regulation of both shoot elongation and flower initiation.

Published in

Plant Cell
2006, Volume: 18, number: 9, pages: 2172-2181

SLU Authors

• Eriksson, Sven

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Böhlenius, Henrik

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Moritz, Thomas

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

• Nilsson, Ove

  • Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1105/tpc.106.042317

Permanent link to this page (URI)

https://res.slu.se/id/publ/9260