Effects of Exogenous Application of Antimicrobial Peptides on Microorganisms and Metabolites in Schima superba

Antimicrobial peptides are important natural components of plant defense against pathogens and are efficient，high-throughput and eco-friendly means of disease resistance. In order to improve the stand quality of Schima superba plantation forests and to verify the effect of antimicrobial peptides on the internal environment of S. superba the internal environment of microorganisms and metabolites of 2-year-old S. superba seedlings was treated by spraying their leaves with a dilute 500-fold antimicrobial peptide bi-distillate solution in 2021 in the state-owned forest farms of Taining，Fujian Province (leaf spraying with bi-distillate as a control)，and the internal environment of microorganisms and metabolites was the internal environment of microorganisms and metabolites was analyzed. The results showed that the abundance of Enterobacteriaceae，Burkholderiaceae，Microflora，Erythrobacteriaceae，Bacillariophyta and Mycobacterium globosum increased significantly (P≤0. 05) after the application of antimicrobial peptide. It indicated that the application of antimicrobial peptides significantly improved the stress tolerance of S. superba and contributed to the growth and development of S. superba. A total of 687 differential metabolites were screened，including 233 up-regulated differential metabolites，accounting for 34%，and 454 down-regulated differential metabolites，accounting for 66%. They were mainly enriched in the ABC transporters pathway，the arachidonic acid metabolism pathway，the flavonoid biosynthesis pathway，the phenylpropanoid biosynthesis pathway. This indicates that addition of antimicrobial peptides can help to improve the energy and material metabolism in S. superba，and enhance the ability of S. superba to respond to adversity stress. The results of this study can provide a reference for the production practice of using antimicrobial peptides to prevent and control the diseases of S. superba to improve the quality of forest stands and to sustain the management of S. superba plantation forests.