Summary
The determination of floral organ identity is determined by members of the MADS box transcription factor family. These transcription factors assemble into larger multimeric complexes that bind DNA to control the expression of the down-stream target genes. Yeast-2-hybrid assays have revealed a number of possible dimer and multimeric complexes formed by at least a dozen of factors that are active in the flower, however, the exact composition of the complexes is largely unknown. Furthermore, little information is available when these complexes are formed during the formation of the flower and the differentiation of the floral organs. Yeast experiments have also demonstrated that the MADS box proteins are able to interact with proteins belonging to another family, in particular TCP transcription factors. TCP transcription factors are supposed to control cell growth and organ shape. We hypothesize that the physical interaction between TCP and MADS box factors provides the link between identity specification and organ growth in the flower. An intriguing question is how and in what combination these transcriptional complexes bind to the DNA to control transcription. The aim of this project is to unveil the composition and dynamics of the transcription complexes that act in the flower to establish the right identity and growth patterns of the floral organs.