Isolation, Identification, and Complete Genome Assembly of an Endophytic Bacillus velezensis YB-130, Potential Biocontrol Agent Against Fusarium graminearum

• Main Authors: Wen Xu, Liyong Zhang, Paul H. Goodwin, Mingcong Xia, Jie Zhang, Qi Wang, Juan Liang, Runhong Sun, Chao Wu, Lirong Yang
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-12-01
• Series: Frontiers in Microbiology
• Subjects: Bacillus velezensis; Fusarium graminearum; DON; biocontrol agent; genome sequencing and assembly
• Online Access: https://www.frontiersin.org/articles/10.3389/fmicb.2020.598285/full

Wheat scab caused by F. graminearum is a highly destructive disease that leads to yield reduction and mycotoxin contamination of grains. In this study, an endophytic bacterium of strain YB-130 was isolated from surface sterilized wheat spikes with scab symptoms and identified as Bacillus velezensis by whole genome annotation, 16S rRNA gene and average nucleotide identities analysis. The whole-genome sequence of strain YB-130 was obtained by PacBio sequencing. 88 putative Carbohydrate-Active Enzymes and 12 gene clusters encoding for secondary metabolites were identified in the YB-130 genome, including one gene cluster for the synthesis of lanthipeptide only found in strain YB-130 genome. In dual cultures, strain YB-130 significantly inhibited the growth of F. graminearum PH-1 and other eight fungal plant pathogens, indicating a broad antifungal activity. Furthermore, strain YB-130 was able to significantly inhibit spore morphology and hyphal development of F. graminearum PH-1. Strain YB-130 also reduced deoxynivalenol production by F. graminearum PH-1 in dual cultures, possibly due to its ability to suppress the expression of tri5, tri3, and tri8 that are required for deoxynivalenol production in F. graminearum. Overall, B. velezensis YB-130 is a promising biological control agent of both F. graminearum infection and mycotoxin production.