Carbon sufficiency boosts phenylpropanoid biosynthesis early in peach fruit development priming superior fruit quality

Manipulating the crop load in peach trees determines carbon supply and optimum balance between fruit yield and quality potentials. The impact of carbon supply on peach fruit quality was assessed in three development stages (S2, S3, S4) on fruit of equal maturity from trees that were carbon (C) starved (unthinned) and sufficient (thinned). Previous studies determined that primary metabolites of peach fruit mesocarp are mainly linked with developmental processes, thus, the secondary metabolite profile was assessed using non-targeted liquid chro-matography mass-spectrometry (LC-MS). Carbon sufficient (C-sufficient) fruit demonstrated superior quality attributes as compared to C-starved fruit. Early metabolic shifts in the secondary metabolome appear to prime quality at harvest. Enhanced C-availability facilitated the increased and consistent synthesis of flavonoids, like catechin, epicatechin and eriodyctiol, via the phenylpropanoid pathway, providing a link between the metab-olome and fruit quality, and serving as signatures of C-sufficiency during peach fruit development.

Automated summary

The manipulation of crop load in peach trees affects carbon supply and the balance between fruit yield and quality. This study assessed the impact of carbon supply on peach fruit quality at different development stages and found that carbon-sufficient fruit had higher quality attributes. The analysis of the fruit's secondary metabolite profile revealed that early metabolic shifts primed fruit quality at harvest, and the synthesis of flavonoids was facilitated by enhanced carbon availability.