Location: Crop Bioprotection Research
Title: Genomic analysis and secondary metabolite production in Bacillus amyloliquefaciens AS 43.3: a biocontrol antagonist of fusarium head blight Authors
Submitted to: Biocontrol
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 13, 2012
Publication Date: January 5, 2013
Citation: Dunlap, C.A., Bowman, M.J., Schisler, D.A. 2013. Genomic analysis and secondary metabolite production in Bacillus amyloliquefaciens AS 43.3: A biocontrol antagonist of Fusarium head blight. Biocontrol. 64(1):166-175. Interpretive Summary: We have sequenced and assembled the complete genome of a beneficial bacteria useful in controlling diseases in wheat. The research will allow us to determine how these beneficial bacteria are able to biologically control plant pathogens. The work provides a blueprint of the number and types compounds the beneficial bacteria can produce, such antifungal compounds toxic to plant pathogens. This breakthrough improves our knowledge of the mode-of-action these beneficial bacteria use, which provides insight on how we may improve their efficacy on crops in the field. Understanding how these beneficial bacteria can control plant diseases has the potential to lead to new methods of crop protection for wheat farmers.
Technical Abstract: The complete genome of the biocontrol antagonist Bacillus amyloliquefaciens AS 43.3 is reported. The 3.9 Mbp genome was sequenced, assembled, and annotated. Genomic analysis of the strain identified ten biosynthetic gene clusters encoding secondary metabolites associated with biocontrol activity. The analysis identified five non-ribosomal peptide synthetase clusters encoding three lipopeptides (surfactin, iturin, and fengycin), a siderophore (bacillibactin), and the antibiotic dipeptide bacilysin. In addition, three polyketide synthetase clusters were identified which encoded for the antibacterials, bacillaene, difficidin, and macrolactin. In addition to the non-ribosomal mediated biosynthetic clusters discovered, we identified a ribosomally encoded biosynthetic cluster that produces the antibiotic plantazolicin. To confirm the gene clusters were functional, cell-free culture supernatant was analyzed using LC-MS/MS. The technique confirmed the presence of all ten metabolites or their derivatives. The study suggests the strain is mostly likely a member of the B. amyloliquefaciens subsp plantarium clade. This study demonstrates the growing importance of applying genomic-based studies to biocontrol organisms of plant pathogens which can enable the rapid identification of bioactive metabolites produced by a prospective biological control organism.