Together or Apart? Unique and redundant functions of MADS-box transcription factors in tomato fruit

Fruit development and ripening in tomato involves coordination and tight regulation of gene expression. MADS-domain transcription factors are important in many biological processes of plants and interactions between MADS-domain proteins are essential for their functions. In tomato (Solanum lycopersicum), several MIKC-type MADS-domain proteins, such as FUL1, FUL2, MADS-RIN, TAGL1, and MADS1, playing a role in fruit development and ripening have been identified, but an in-depth characterization of their unique and (partially) redundant functions is lacking. In this project, we aim to elucidate further the tomato fruit development and ripening regulation exerted by MADS-box TFs and their interactions among each other and with other genes, particularly for FUL1, FUL2 and TAGL1. We will use CRISPR/Cas and RNAi to generate single mutants and combinations thereof to reveal any redundant functions or cooperativity among these TFs during fruit development and ripening. Second, we also analyze the detailed temporal and spatial expression of the FULs, to identify specific targets and co-factors. Third, using the results we aim to study the effect of natural variation in FUL1 and to develop a refined regulatory model of tomato fruit ripening from mutagenesis, expression profiles and interaction data. Altogether, this study will unveil the molecular regulatory network of MADS-BOX together with other TFs and of FUL1/2 in fruit development and ripening.