Metabolome and Microbiome Signatures in the Leaves of Wild Tea Plant Resources Resistant to Pestalotiopsis theae

Tea is an important crop mainly applied in food industries. This study investigated the resistance factors of wild tea plant resource to tea grey blight disease, caused by Pestalotiopsis theae , in the metabolome and microbiome. In the interaction analysis of tea leaves and pathogenic fungi, the resistance of wild tea plant resource R1 to tea grey blight disease was significantly higher than that of wild tea plant resource S1 . In the metabolome, the difference was obvious between R1 and S1. There are 145 significantly changed metabolites . The phenolic acids and flavonoids were the major increased categories in R1, such as 4-O-Glucosyl-sinapate and petunidin-3-o-6-o-p-coumaroyl rutinoside. Six metabolic pathways were significantly enriched, such as aminoacyl-tRNA biosynthesis, flavone and flavonol biosynthesis. In terms of bacteria, there was not significant difference between S1 and R1 in the principal component analysis and pseudomonas was the major bacterial genus in S1 or R1. In addition, the two resources have their own predominant genus. Cellvibirio was predominant genus of S1 and Candidatus_competibacter was predominant genus of R1. In terms of fungal, the fungal diversity and abundance of two tea plant resource samples can be distinguished clearly. The fungal composition of S1 was more abundant than that of R1 at the genus level. Toxicocladosporium and Filobasidium were predominant fungal genuses in S1 and R1, repectively. The relative abundance of unclassified-norank-norank-chloroplast and penicillium were significantly different between S1 and R1. They correlated with some metabolites enriched in S1 or R1, such as L-arginine and quercetin-3-o-2-o-rhamnosyl rutinoside-7-o-glucoside. Overall, phenolic acids and flavonoids and penicillium could be functional metabolites or microorganism that contributed to improving the resistance of wild tea plant resource to tea grey blight disease.