Ancient bayberry increased stress resistance by enriching tissue-specific microbe and metabolites (PRJCA018258)

The ancient bayberry exhibited greater resistance to biotic and abiotic stresses compared with the cultivated bayberry, but the underlying mechanism is still being unexplored. Objectives: This work aims to reveal if long-term bayberry planting can enhance stress resistance by increasing tissue-specific microbe and metabolites. Using prokaryotic and fungal amplicon sequencing in combination with untargeted mass spectrometry analysis, this study investigated the role of endosphere and rhizosphere microbial community structure and metabolites in the differential resistance between ancient bayberry and cultivated bayberry trees. Results: Following the identification of the core microbiome and metabolites in different bayberry compartments, it can be inferred that the increased resistance of ancient bayberry to biotic and abiotic stresses could be attributed to the change of rhizosphere and endosphere microbial communities and secondary metabolites. Indeed, Bacillus was enriched in the roots and stems, Pseudomonas was enriched in the leaves, and Mortierella was enriched in the rhizosphere soil of ancient bayberry. The importance of microbe in the resistance of ancient bayberry to biotic and abiotic stresses was further justified by the correlation analysis of the enriched species with the increased contents of resistance associated metabolites, which include beta-myrcene, benzothiazole, L-glutamic acid and gamma-aminobutyric acid based on GC-MS metabolomics analysis. The beneficial role of resistance associated metabolites was determined by evaluating the promotive and allelopathic effect as well as phytostatic and antioxidant function of L-glutamic acid in lettuce plants. The intrinsic reason for the greater resistance of ancient bayberry to biotic and abiotic stresses was elucidated by evaluating the influence of long-term planting on the microbial community and metabolites in bayberry endosphere and rhizosphere and understanding the complex host-microbial interactions.