The alternative sigma factor D is known to be involved in at least three biological processes in Bacilli: flagellin synthesis, methyl-accepting chemotaxis, and autolysin synthesis. Although many Bacillus genes have been identified as SigD regulon, the list may be not completed. With a microarray-based systemic screening, we found a set of genes down-regulated in the sigD knock-out mutant of the plant growth promoting rhizobacterium B. amyloliquefaciens subsp. plantarum FZB42. Eight genes (appA, blsA, dhaS, spoVG, yqgA, RBAM_004640, RBAM_018080, and ytk) were further confirmed by quantitative PCR and/or Northern blot to be controlled by SigD at the transcriptional level. These genes are hitherto not reported to be controlled by SigD. Among them, four genes are of unknown in functions; two genes (RBAM_004640 and RBAM_018080), absent in the model strain B. subtilis 168, are unique to B. amyloliquefaciens stains. The eight genes are involved in sporulation, biofilm formation, metabolite transport and several other functions. The findings extend our knowledge of the regulatory network governed by SigD in Bacillus and will further help to decipher the roles of the genes.
- Received August 30, 2016.
- Accepted October 17, 2016.
- © 2016. Published by The Company of Biologists Ltd
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