Metabolomic and Transcriptomic Analyses Reveal the Differential Response Model of Cultivated Tea and Wild Tea Resources against Pestalotiopsis theae.

Tea gray blight caused by Pestalotiopsis theae threatens tea production. We investigated the differential responses in two cultivated ("JX", "YJ") and two wild tea resources ("R", "S") via metabolomics, transcriptomics, and in vitro analyses. Phenotypically, resistance ranked "JX" > "R" > "YJ" > "S", with "JX" and "R" showing stronger resistance. Metabolomically, a total of 1062 differentially accumulated metabolites (DAMs) responded to infection. Resistant materials were enriched with lipids, alkaloids, etc., while susceptible materials were enriched with flavonoids, amino acids, etc. Transcriptomically, 32,168 differentially expressed genes (DEGs) were identified. Resistant materials upregulated more genes involved in hormone signaling and phenylpropanoid biosynthesis, with WRKY TFs (CsWRKY75/65/30) as key regulators. "JX" accumulated higher levels of dihydromyricetin, myricetin, quercetin, and kaempferol than "YJ", which effectively inhibited P. theae. This study elucidates the molecular-metabolic regulatory mechanism underlying tea plant resistance to P. theae, providing a theoretical framework for resistance breeding and natural antifungal agents for green disease control.