Variations of the peach fruit transcriptome during ripening and in response to hormone treatments

Peach has fleshy climacteric fruits. Their ripening is controlled by both endogenous and exogenous signals to link the genetic determinants with the environmental conditions. Genomic tools, such as microarray RNA profiling, offer new prospects to study in a holistic way complex biological problems such as fruit ripening. We have adopted a microarray approach to monitor transcriptome changes in peach fruits during their transition from a preclimacteric to a climacteric stage. Furthermore, the variations of gene transcription mediated by applications of exogenous ethylene and auxin to pre-climacteric fruits have also been analysed. In peach fruits the ripening process needs vast transcriptional changes to occur, and the hormone ethylene controls many of these changes. Among the many variations occurring during ripening, we observed that some genes coding for various isoforms of the glycolytic enzymes were up-regulated. Several hypotheses are presented to account for these results.