Present address: Department of Plant Biology, Michigan State University, East Lansing, MI 48824-1312, USA.
The MADS domain factors AGL15 and AGL18 act redundantly as repressors of the floral transition in Arabidopsis
Article first published online: 23 MAY 2007
The Plant Journal
Volume 50, Issue 6, pages 1007–1019, June 2007
How to Cite
Adamczyk, B. J., Lehti-Shiu, M. D. and Fernandez, D. E. (2007), The MADS domain factors AGL15 and AGL18 act redundantly as repressors of the floral transition in Arabidopsis. The Plant Journal, 50: 1007–1019. doi: 10.1111/j.1365-313X.2007.03105.x
- Issue published online: 23 MAY 2007
- Article first published online: 23 MAY 2007
- Received 31 January 2007; accepted 20 February 2007
- MADS box;
- AGAMOUS-like 15;
- AGAMOUS-like 18;
- flowering time;
- FLOWERING LOCUS T
The developmental roles of AGL15 and AGL18, members of the AGL15-like clade of MADS domain regulatory factors, have not been defined previously. Analysis of transgenic Arabidopsis plants showed that overexpression of AGL18 produces the same phenotypic changes as overexpression of AGL15, and the two genes have partially overlapping expression patterns. Functional redundancy was confirmed through analysis of loss-of-function mutants. agl15 agl18 double mutants, but not single mutants, flower early under non-inductive conditions, indicating that AGL15 and AGL18 act in a redundant fashion as repressors of the floral transition. Further genetic analyses and expression studies were used to examine the relationship between AGL15 and AGL18 activity and other regulators of the floral transition. AGL15 and AGL18 act upstream of the floral integrator FT, and a combination of agl15 and agl18 mutations partially suppresses defects in the photoperiod pathway. agl15 agl18 mutations show an additive relationship with mutations in genes encoding other MADS domain floral repressors, and further acceleration of flowering is seen in triple and quadruple mutants under both inductive and non-inductive conditions. Thus, flowering time is determined by the additive effect of multiple MADS domain floral repressors, with important contributions from AGL15 and AGL18.