Abstract

USDA -ARS Robert W. Holley Center and Boyce Thompson Institute for Plant Research, Tower Road, Cornell University. Ithaca, NY 14853 USA

Fleshy fruit undergo a complex set of changes in physiology and chemistry to become attractive and palatable to frugivores that consume them and disperse the seeds contained within. Tomato is a model for ripening where plant hormones, transcription factors and changes in the epigenome all contribute to ripening control. Natural mutations, transgenic repression/over-expression and gene editing mutants have all given insights into the functions and roles of ripening regulators with new players continually being added to the symphony of participants coordinating the manifestation of ripening phenomena. As fruit do not ripen uniformly, we have recently deployed tissue-specific gene expression profiling to explore more deeply the ripening regulome in an effort to reveal additional regulators and where they operate. Resulting gene expression data is freely available through the Tomato Expression Atlas (TEA) at tea.solgenomics.net. We have used this data in part to develop and support our hypothesis that key ripening events initiate in the locule tissue and spread to the carpel tissue. A number of new ripening-associated transcription factors consistent with this profile have been identified and reveal functions consistent with this ripening pattern. Some influence ripening at the level of specific ripening processes such as softening while others exert broader ripening control. Identification of the players in ripening regulation is requisite to developing a more complete picture of its basic regulatory machinery and to begin understanding how ripening regulators interact.