Functional Genomic Analysis of Fruit Flavor and Nutrition Pathways

University Of Florida, Gainesville FL

Investigators

Abstract

Fruits are major components of the human diet contributing a large portion of vitamins, minerals, antioxidants, and fiber. While flavor and nutrition composition have clear potential for positive human benefit, they have proven to be difficult traits to modify via traditional breeding due to their generally complex biosynthetic and regulatory pathways. "Flavor" in many fruits is the product of a complex interaction among sugars, acids and multiple volatile compounds. Synthesis and accumulation of these compounds is the result of coordinated activity of many genes. In many cases, the pathways for synthesis of these compounds have yet to be established. This program will focus on the expression of the genes critical for metabolism of these compounds so that key regulators of fruit flavor and nutrient composition can be identified and eventually manipulated via the many possible routes available. Specifically, the program will apply gene expression profiling to an extensive set of germplasm to 1) map regulatory circuits controlling the levels of important components of flavor and nutrition, and 2) identify genes encoding enzymes involved in metabolism of these components. Levels of expression of most of the genes expressed during tomato fruit ripening will be correlated with the abundances of specific metabolites in a diverse set of germplasm consisting of mutants, transgenic and recombinant inbred lines. Bioinformatics will be used to identify genes whose expression is linked to appearance of target compounds. The value of these markers as predictors of chemical composition will be tested by genetic mapping and transgenic manipulation. These experiments will have broad impact by 1) mapping critical steps controlling flavor and nutrition metabolic pathways, 2) identifying specific genes involved in either regulation or metabolism of critical components of flavor and nutrition, 3) providing useful tools for breeding and engineering improved fruit quality, and 4) establishing a correlative public database of metabolites and global gene expression that will be accessible for a broad array of ripening-related studies.