A candidate gene survey of quantitative trait loci affecting chemical composition in tomato fruit

BERMÚDEZ L.; URIAS U.; MILSTEIN D.; KAMENETZKY L.; ASIS R.; FERNIE A. R.; VAN SLUYS M.A.; CARRARI F.; ROSSI M.

JOURNAL OF EXPERIMENTAL BOTANY

Oxford University Press

Año: 2008 vol. 59 p. 2875 - 2890

0022-0957

In tomato, numerous wild-related species have demonstrated to be untapped sources of valuable genetic variability including pathogen-resistance genes, nutritional and industrial quality traits. From a collection of S. pennellii introgressed lines, 889 fruit metabolic loci (QMLs) and 326 yield-associated loci (YALs), distributed across the tomato genome, were previously identified. By using a combination of molecular marker sequence analysis, PCR amplification and sequencing, analysis of allelic variation, and evaluation of co-response between gene expression and metabolite composition traits, the present report, provides a comprehensive list of candidate genes co-localising with a subset of 106 QML and 20 YAL associated either with important agronomic or nutritional characteristics. This combined strategy allowed the identification and analysis of 127 candidate genes located in sixteen regions of the tomato genome. Eighty-five genes were cloned and partially sequenced totalising 45,816 and 45,787 bases from S. lycopersicum and S. pennellii, respectively. Allelic variation at the amino acid level was confirmed for 37 of these candidates. Furthermore, out of the 127 gene metabolite co-locations, some were recovered following correlation of parallel transcript and metabolite profiling. Results obtained here represent the initial steps in the integration of genetic, genomic and expressional patterns of genes colocalising with chemical compositional traits of the tomato fruit.