Regulation of Flowering Time

MADS-domain transcription factors both positively and negatively regulate the vegetative-to-reproductive transition in plants.  The MADS-domain factors AGL (AGAMOUS-Like)15 and AGL18 act to repress the expression of FT (FLOWERING LOCUS T).  FT functions as a mobile signal that results in developmental reprogramming at the shoot apical meristem and a shift from the production of leaves to the production of floral tissues.  We are examining the action of AGL15 and AGL18 relative to the other MADS-domain floral repressors FLC, FLM, SVP, and MAF2-5.   When the floral repressors are sequentially removed by mutations, the plants flower at younger and younger ages. When AGL15 or AGL18 are over-expressed, the plants flower later and other developmental transitions, including floral organ abscission and senescence, are delayed.

Supported by the National Science Foundation.

See Adamczyk, B.J., M.D. Lehti-Shiu, and D.E. Fernandez (2007).  The MADS domain factors AGL15 and AGL18 act redundantly as repressors of the floral transition in Arabidopsis.  Plant J. 50: 1007-1019. 

Fang, S.-C., and D.E. Fernandez (2002).  Effect of regulated overexpression of the MADS domain factor AGL15 on flower senescence and fruit maturation.  Plant Physiol. 130: 78-89. 

Fernandez, D.E., G.R. Heck, S.E. Perry, S.E. Patterson, A.B. Bleecker, and S.-C. Fang (2000).  The embryo MADS domain factor AGL15 acts post-embryonically: inhibition of perianth senescence and abscission via constitutive expression.  The Plant Cell 12: 183-198.