Metabolomics and WGCNA Analyses Reveal the Underlying Mechanisms of Resistance to Botrytis cinerea in Hazelnut

This study provides that the elevated levels of these compounds (flavonoids and phenolic acids) contribute substantially to the resistance of hazelnut against <i>B. cinerea</i>. Furthermore, 3,4-hydroxyphenyllactic acid and phloretin were identified as pivotal metabolites in modulating the resistance of hazelnut to <i>B. cinerea</i>. Through WGCNA analyses, we identified four transcription factors (WRKY19, HSFC1, ERF071, and RAP2-1) that are most likely to regulate the synthesis of 3,4-dihydroxyphenyllactic acid and phloretin. This study provides crucial insights for further investigation into the regulatory network of metabolites associated with hazelnut resistance to <i>B. cinerea</i>.