Analysis of gene expression during the fruit set of tomato: A comparative approach

The study of tomato fruit set and early fruit development is of upmost importance due to their economic implications for crop production. Moreover, they are good subjects in the attempt to understand plant development control. In this work, we isolated more than 400 genes that are differentially expressed during these processes in tomato by using two complementary approaches: suppressive subtractive hybridization and genomic comparative analysis. We made a tomato flower library enriched in genes differentially expressed at 3 DPA when compared against anthesis. The library subtraction showed the high variability of genes and pathways implicated in this process. Using the AtGenExpress data from Arabidopsis, we detected 1879 genes differentially expressed during fruit set and early development. The expression of their orthologue tomato genes was tested by quantitative PCR, and more than 75% of the genes were also differentially expressed in tomato, meaning there is a conservation between these two species in spite of the significant differences in fruit morphology and development. We detected known and unknown fruit development genes and pathways, and this data will be a good source of information for future experiments about fruit set in tomato and Arabidopsis. We also showed that this transcriptomic comparative approach is very useful in identifying target genes of conserved processes in species where microarray facilities are not available, making the work with model species more profitable.