Location: Food Quality Laboratory2012 Annual Report
1. A new family of genes involved in regulation of tomato fruit development, ripening, and quality. Rapid softening and over-ripening as well as chilling injury and storage decay are problems that limit the shelf life and increase losses of tomato fruit. It is well documented that fruit treatment with calcium can delay and extend ripening and softening, but the mechanism is unclear. A family of seven tomato SR genes was cloned and characterized, providing a good explanation for the benefits of calcium on fruit quality. The encoded SRs are calcium-regulated proteins called transcription factors that control developmental processes like ripening as well as defense responses to decay organisms and stress. Research results indicated that tomato SR genes serve as a nexus for signaling pathways controlling ripening and stress responses. This knowledge can be used by plant scientists to elucidate the complex interactions of regulators of fruit ripening, and by plant geneticists and breeders for development of new tomato lines that better retain fruit quality after harvest. Such new tomato lines will reduce the estimated 10-15% post-harvest losses annually, saving millions of dollars for growers, packers, and retailers.
2. Gene required for anthocyanin production in strawberry fruit is identified. Dietary intake of health-promoting phytonutrients such as anthocyanins, the red and blue pigments found in many fruits, is recommended by USDA as a means to combat chronic inflammatory diseases and certain cancers. One way to increase the intake of these phytonutrients is to develop new “super fruit” lines with higher concentrations of the compounds. A last step in biosynthesis of anthocyanins involves the attachment of a sugar catalyzed by an enzyme called UGT. The gene encoding strawberry UGT1 was cloned, and its expression was shown to be fruit specific and directly correlated with anthocyanin accumulation. This finding provides strawberry breeders and plant geneticists a single target gene that can be manipulated to increase accumulation of health-beneficial anthocyanins in strawberry fruit. A long-range benefit of this research is a reduced incidence of diabetes, cardiovascular disease, and other chronic health problems in the U.S. that cost many billions of dollars annually.
Ma, C., Dastmalchi, K., Whitaker, B.D., Kennelly, E. 2011. Two new antioxidant malonated caffeoylquinic acid isomers in fruits of wild eggplant relatives. Journal of Agricultural and Food Chemistry. 59:9645-9651.
Yang, T., Peng, H., Whitaker, B.D., Conway, W.S. 2012. Characterization of a calcium/calmodulin-regulated SR/CAMTA gene family during tomato fruit development and ripening. Biomed Central (BMC) Plant Biology. 12:19.