Multi-omics analysis reveals synergistic effects of terpenoids and phenylpropanoid compounds on flavour formation in skin and pulp of 'Shine Muscat' grape.

Abstract

Flavour is a key trait that determines table grape quality and marketability. However, specific volatile compounds remain inadequately characterised. In this study, we have performed a comprehensive analysis of the volatile compounds in Muscat 'Shine Muscat' and no-flavour 'Thompson Seedless' during three different stages using widely targeted metabolomics and transcriptomics. Using widely targeted metabolomics, nine categories of 46 key aromatic compounds were identified, with esters and terpenoids playing pivotal roles in defining the skin and pulp of Muscat. Notably, strong correlations were observed between terpenoids and esters, indicating a synergistic effect on the Muscat flavour. Furthermore, weighted gene co-expression network analysis revealed that differentially expressed genes co-expressed with 14 compounds, forming a regulatory network regulated by genes and transcription factors involved in the synthesis of terpenoids and esters. These findings deepen our understanding of Muscat grape aroma profiles and offer practical guidance for optimising table grape breeding and processing technologies.