Diurnal compositional changes in pericarp of tomato fruit
Résumé
This work is part of the Eranet EraSysBio+ FRuit Integrative Modelling project, aimed at characterizing and modelling the effect of environmental factors on carbon metabolism of tomato fruit during its development. Whereas diurnal changes in the biochemical composition of leaves have been described for a long time and a range of species, very few studies describe diurnal changes in fleshy fruit. We studied the diurnal compositional changes in tomato (Solanum lycopersicum L. cv Money Maker) pericarp of fruit at two stages of development (expansion phase and ripening). Greenhouse-grown tomato fruit at 30 days post-anthesis and at maturity were harvested throughout a day and night cycle. Metabolites were determined using targeted and untargeted analyses (enzymatic, GC-TOF-MS, LC-QqTOF-MS or 1H-RMN) of polar or semi-polar extracts. Multivariate analyses allowed separating harvest times and highlighting discriminant analytes. Mean comparison of each identified compound revealed that the absolute or relative concentration of several metabolites was significantly modified during the photoperiod. However, diurnal changes were much more limited in fruits than those usually found in leaves, and could be ignored when building a model for the changes of metabolic composition across fruit ripening. This work will be complemented with the study of mature leaves close to the harvested fruit cluster for plants grown under usual commercial conditions or under carbon stress.