Isolation, identification, and genome of a Bacillus velezensis JIN4 exhibiting biocontrol activity against kiwifruit bacterial canker

Abstract

Kiwifruit bacterial canker is a devastating disease in production. This study aimed to screen antagonistic bacteria that might be used to control this disease. Strain JIN4 showed significant antifungal activity against Pseudomonas syringae pv. Actinidiae (Psa) and seven other phytopathogenic bacteria isolated from kiwifruit branches. Based on morphological, physiological, and biochemical characteristics, 16S rDNA sequence analysis, and gyrA sequence analysis, JIN4 was identified as Bacillus velezensis. In field prevention experiments, the control efficiency of strain JIN4 reached 60.22%. Our results indicate that B. velezensis JIN4 has broad-spectrum antifungal resistance, and its genome contains many genes encoding enzymes involved in the synthesis of antimicrobial metabolites. In addition, JIN4 has three antibiotic-resistance genes and a cluster of nine genes used in the synthesis of secondary metabolites with antimicrobial activity. In conclusion, B. velezensis JIN4 can be used as a potential biocontrol agent against kiwifruit bacterial canker, but further work is required to improve its efficacy.