Molecular and biochemical detection of lipopeptide antibiotics producing Bacillus spp., antagonistic to common fungal pathogens of canola (Brassica napus L.)
Bacillus cereus strain DFE4, B. amyloliquefaciens strains DFE16 and BS6 exhibitedin vitro and in vivo antagonistic activity towards Leptosphaeria maculans (Desm.) Ces & De Not, the blackleg pathogen and Sclerotinia sclerotiorum (Lib.) de Bary, the stem rot pathogen of canola (Brassica napus L.). Role of antifungal lipopeptide antibiotics, produced by these Bacillus spp., in plant disease control was investigated. The presence of the biosynthetic genes of the multi-modular peptide synthetases,responsible for the production of the lipopeptides, was detected with newly designed specific-PCR primers. Strains DFE4 and DFE16 tested positive for the presence of the biosynthetic genes of surfactin, iturin A and bacillomycin D, and strain BS6 for iturin A and bacillomycin D. The surfactin specific primers amplified a 441 bp product, while the bacillomycin D and iturin A specific primers amplified an 875 bp and 647 bp product, respectively. The purified PCR products, when sequenced and searched in the nBLAST-NCBI database, showed very high homology to the sequences of their respective biosynthetic genes in reference B. subtilis strains fiom the GenBank. Production of the lipopeptide antibiotics by these isolates was detected through MALDI-TOF-MS, which confirmed the molecular detection of the peptide synthetase biosynthetic genes. This is the first report on the molecular and biochemical detection of antifungal lipopetide antibiotics produced by Bacillus spp., isolated from canola and antagonistic to economically important fungal pathogens of canola worldwide. This is also the first report of a B. cereus strain to harbor the biosynthetic genes and produce surfactin, iturin A and bacillomycin D.
Canola Blackleg Bacillus spp. lipopeptide antibiotics biosynthetic genes biocontrol
Rajesh Ramarathnam W.G.Dilantha Fernando
Department of Plant Science, University of Manitoba, Winnipeg, MB, R3T 2N2 Canada
国际会议
第十二届国际油菜大会( The 12th International Rapeseed Congress)
武汉
英文
1444-1447
2007-03-26（万方平台首次上网日期，不代表论文的发表时间）