The analyses of the mechanism of B. velezensis RT2 on early blight of capsicum based on whole genome sequencing

Objective To analyze the RT2 genome sequence of B. velezensis with a view to exploring the mechanism of its function in early blight of capsicum.

Methods PacBio sequencing technology was applied, and the whole genome of B. velezensis RT2 was combined to predict and annotate the secondary metabolite gene clusters.

Results The whole genome length, GC content and coding genes of RT2 were 3 932 504 bp, 46.53%, 3 725, 86 tRNA, 81 sRNA and 27 rRNA, respectively. 7 prophages, 2 CRISPR-Cas and 9 genomic islands were discovered in strain RT2. Functional annotations of 3 711, 2 592, 2 151, 2 961, 3 332 and 2 812 genes were obtained in the NR, GO, KEGG, eggNOG, Pfam and Swiss-Prot databases, respectively. In CA-Zyme, chitinase and other enzyme genes can degrade the fungal cell wall. In addition, gene clusters encoding bacteriostatic substances for RT2 were predicted, eight of which showed high conserved activity in RT2.

Conclusion The genome of B. velezensis RT2 encodes multiple synthetic gene clusters that produce antimicrobial active secondary metabolites and also contains key genes that break down the cell wall of pathogenic fungi. These characteristics are important factors for RT2 to resist early phytophthora capsicum.