Erschienen:
American Society for Microbiology, 2007
Erschienen in:Applied and Environmental Microbiology
Sprache:
Englisch
DOI:
10.1128/aem.00565-07
ISSN:
0099-2240;
1098-5336
Entstehung:
Anmerkungen:
Beschreibung:
<jats:title>ABSTRACT</jats:title><jats:p>Environmental strain<jats:italic>Bacillus amyloliquefaciens</jats:italic>FZB42 differs from the domesticated model organism of the same genus,<jats:italic>Bacillus subtilis</jats:italic>168, 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 of<jats:italic>B. amyloliquefaciens</jats:italic>FZB42, bacillomycin D, is regulated in multiple layers. Expression of the bacillomycin D operon (<jats:italic>bmy</jats:italic>) is dependent on a single σ<jats:sup>A</jats:sup>-dependent promoter, P<jats:sub>bmy</jats:sub>and 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 of<jats:italic>bmy</jats:italic>. 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.</jats:p>