Objective  To explore the resistance molecular mechanism of tea plants to the pathogen of tea blister blight, and to explore the resistance-related genes, so as to provide a basis for resistance breeding of tea plants.

  Methods  Differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were compared between healthy leaves (CK) and leaves infected with blister blight disease (TB) by transcriptome sequencing and metabolome analysis.

  Results  Transcriptome data showed that there were 1009 DEGs between CK and TB, and GO enrichment analysis indicated that the DEGs were involved in cell wall metabolism and the regulation of chitinase activity, oxidoreductase activity, and xyloglucan:xyloglucanosyltransferase activity. KEGG metabolic pathway analysis showed that the DEGs were significantly enriched in pathways of "Flavonoid biosynthesis", "Phenylpropanoid biosynthesis", "Amino sugar and nucleotide sugar metabolism", "Glycerolipid metabolism", and "Stilbenoid, diarylheptanoid and gingerol biosynthesis". 47 transcription factors in DEGs belonging to 21 transcription factor families, mainly including bHLH, SBP, AP2/ERF-AP2 and MYB, etc., which may be important regulatory genes in the process of tea plant to blister blight disease. A total of 353 DAMs were identified using widely targeted metabolomics, and the DAMs were mainly enriched in the pathways of "Flavonoid biosynthesis", "Lysine biosynthesis", and "Alanine, aspartate and glutamate metabolism". Integrative analysis of transcriptome and metabolome revealed that the pathways with significant co-enrichment were "Flavonoid biosynthesis", "Phenylpropanoid biosynthesis", "Stilbenoid, diarylheptanoid and gingerol biosynthesis". A total of 20 DEGs and 15 DAMs related to the phenylpropanoids and flavonoids biosynthesis pathways were screened out. Among them, DEGs such as CSS0011741（4CL）、CSS0002940（DFR）、CSS0015968（DFR）and CSS0010687（ANS）were up-regulated in susceptible leaves. DAMs such as phloretin, phlorizin, 4-Hydroxystyrene, p-Coumaroyl quinic acid, dihydromyricetin, epigallocatechin and peonidin 3-O-glucoside were accumulated in susceptible leaves.

  Conclusion  DEGs in the pathways of "Phenylpropanoid biosynthesis" and "Flavonoid biosynthesis" play important roles in the response of tea plant to tea blister blight disease infestation, and DAMs such as phloretin, phlorizin, and epigallocatechin may be important secondary metabolites for tea plant resistance to blister blight disease.