title: Lipopeptides, a novel protein, and volatile compounds contribute to the antifungal activity of the biocontrol agent Bacillus atrophaeus CAB-1.
abstract: Bacillus atrophaeus CAB-1 displays a high inhibitory activity against various fungal pathogens and suppresses cucumber powdery mildew and tomato gray mold. We extracted and identified lipopeptides and secreted proteins and volatile compounds produced by strain CAB-1 to investigate the mechanisms involved in its biocontrol performance. In vitro assays indicated all three types of products contributed to the antagonistic activity against the fungal pathogen Botrytis cinerea. Each of these components also effectively prevented the occurrence of the cucumber powdery mildew caused by Sphaerotheca fuliginea under greenhouse conditions. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry revealed that the major bioactive lipopeptide was fengycin A (C15-C17). We isolated the crude-secreted proteins of CAB-1 and purified a fraction with antifungal activity. This protein sequence shared a high identity with a putative phage-related pre-neck appendage protein, which has not been reported as an antifungal factor. The volatile compounds produced by CAB-1 were complex, including a range of alcohols, phenols, amines, and alkane amides. O-anisaldehyde represented one of the most abundant volatiles with the highest inhibition on the mycelial growth of B. cinerea. To our knowledge, this is the first report on profiling three types of antifungal substances in Bacilli and demonstrating their contributions to plant disease control.
authors.affiliation: Plant Protection Institute, Hebei Academy of Agricultural and Forestry Sciences, Integrated Pest Management Center of Hebei Province, Key Laboratory of IPM on Crops in Northern Region of North China, Ministry of Agriculture, Baoding, 071000, China.
authors.forename: Xiaoyun
authors.initials: X
authors.lastname: Zhang
authors.forename: Baoqing
authors.initials: B
authors.lastname: Li
authors.forename: Ye
authors.initials: Y
authors.lastname: Wang
authors.forename: Qinggang
authors.initials: Q
authors.lastname: Guo
authors.forename: Xiuyun
authors.initials: X
authors.lastname: Lu
authors.forename: Shezeng
authors.initials: S
authors.lastname: Li
authors.forename: Ping
authors.initials: P
authors.lastname: Ma
mesh_terms: D000898:Antibiosis; D001203:Ascomycota / Q000187:drug effects / Q000254:growth & development*; D001407:Bacillus / Q000378:metabolism / Q000502:physiology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D018553:Cucumis sativus / Q000382:microbiology; D055666:Lipopeptides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D008826:Microbial Sensitivity Tests; D010935:Plant Diseases / Q000382:microbiology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D055549:Volatile Organic Compounds / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D055666:Lipopeptides; D055549:Volatile Organic Compounds