Genetic interactions of the Arabidopsis flowering time geneFCA,with genes regulating floral initiation
The genes controlling the timing of the transition from vegetative to reproductive growth are likely candidates for regulators of genes initiating floral development. We have investigated the interaction of one particular gene controlling flowering time,FCA, with the meristem identity-genesTERMINAL FLOWER 1(TFL1),APETALA 1(AP1) andLEAFY(LFY) and the floral repression geneEMBRYONIC FLOWER 1(EMF1). Double mutant combinations were generated and the phenotypes characterized. The influence of strong and intermediatefcamutant alleles on the phenotype conferred by a35S-LFYtransgene was also analysed. The results support a model whereFCAfunction promotes flowering in multiple pathways, one leading to activation ofLFYandAP1, and another acting in parallel withLFYandAP1. Only the latter pathway is predicted to be non-functional in the intermediatefca-4allele. The results are also consistent withAP1andTFL1negatively regulatingFCAfunction. Combination of Columbiafcaandemf1mutant alleles confirmed thatFCAis required for the early flowering ofemf1. EMF1andFCAare therefore likely to operate in different floral pathways.
Document Type: Original Article
Affiliations: 1: Department of Molecular Genetics, John Innes Centre, Colney, Norwich NR4 7UH, UK, and 2: Graduate Institute of Agricultural Biotechnology, National Chung Hsing University, Taichung, Taiwan 40227, Republic of China
Publication date: February 1, 1999