Published:
American Society for Microbiology, 2007
Published in:
Applied and Environmental Microbiology, 73 (2007) 21, Seite 6953-6964
Language:
English
DOI:
10.1128/aem.00565-07
ISSN:
0099-2240;
1098-5336
Origination:
Footnote:
Description:
ABSTRACTEnvironmental strainBacillus amyloliquefaciensFZB42 differs from the domesticated model organism of the same genus,Bacillus subtilis168, in its ability to promote plant growth and suppress plant-pathogenic organisms present in the rhizosphere. This behavior is exerted mainly through the production of several nonribosomal cyclic lipopeptides and polyketides, which exhibit a broad range of action against phytopathogenic bacteria, fungi, and nematodes. Here, we provide evidence that the synthesis of the main antifungal agent ofB. amyloliquefaciensFZB42, bacillomycin D, is regulated in multiple layers. Expression of the bacillomycin D operon (bmy) is dependent on a single σA-dependent promoter, Pbmyand is favored in its natural host by the small regulatory protein DegQ. The global regulators DegU and ComA are required for the full transcriptional activation ofbmy. DegU retains a key role since it binds directly to two sites located upstream of the bacillomycin D promoter. Moreover, both DegU and a transmembrane protein of unknown function, YczE, act on a later level of gene expression, exerting their posttranscriptional effects in a hitherto-unknown manner.