659 Genetic Control of Fruit Quality and Prospects for Nutrient Modification

Abstract

Recent advances in molecular genetics and genomics technologies have had a significant impact on tomato research over the last decade and are likely to have considerable influence on the nature and outcome of research activities related to tomato in the future. Specific applications of genomics technologies in our laboratory include positional cloning of genes associated with fruit ripening and quality (rin and nor), localization of ripening-related genes on the molecular-marker map to assist candidate gene discovery related to fruit ripening and quality, and characterization of mutants influencing fruit quality and nutritional value with the goal of identifying candidate genes for said mutants and alternative molecular tools for modification of fruit quality and nutrition. Isolation of the rin and nor genes has been verified via complementation of corresponding mutant tomato plants via insertion of the appropriate CaMV35s-driven wild-type sense cDNA. Both the rin and nor genes have sequence characteristics suggestive of transcription factors. Preliminary evidence suggests the role of similar genes in the ripening of additional climacteric and non-climacteric fruit species. Additional efforts in the laboratory include molecular analyses of light signal transduction as related to 1) regulation of carotenoid and flavonoid accumulation, and 2) potential manipulation of corresponding pathways for modification of fruit quality and nutrient value.