Cell Individuality: The bistable gene expression of the type III secretion system in Dickeya dadantii 3937

Department of Biological Sciences, University of Wisconsin, Milwaukee, WI, USA.
Molecular Plant-Microbe Interactions (Impact Factor: 3.94). 01/2012; 25(1):37-47. DOI: 10.1094/MPMI-05-11-0105
Source: PubMed


Dickeya dadantii 3937 is a gram-negative phytopathogenic bacterium that expresses genes encoding a type III secretion system (T3SS) in a bistable pattern when cultured in a homogeneous minimal media. In this work, we further characterized the bistable gene expression of T3SS at the single-cell level. We demonstrated that bistable expression of the HrpL-regulon genes, such as hrpA and hrpN, is controlled by the same regulatory mechanism. We also showed that the expression level of the T3SS master regulatory gene hrpL plays an important role in the development of the bistable expression of hrpA. A high expression level of hrpL is required but unable to guarantee the high-state expression of hrpA in a cell. In addition, bistable expression patterns of T3SS genes in other gram-negative pathogens of the Enterobacteriaceae and Pseudomonadaceae families were also described in this study. This suggests that the T3SS bistability might be a conserved population behavior in several gram-negative bacterial pathogens.

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    • "DH5α … supE44 lacU169 (φ80lacZ M15) hsdR17 recA1 endA1 gyrA96 thi-1 relA1 Sambrook and Russell 2001 S17-1 λpir … λ(pir) hsdR pro thi; chromosomally integrated RP4-2 Tc::Mu Km::Tn7 Simon et al. 1983 Plasmids pMiniHimar RB1 … Km r ; plasmid carrying mini-Himar RB1, oriR6K oriT lacZ Bouhenni et al. 2005 pPROBE-AT … Ap r ; promoter-probe vector Miller et al. 2000 pPdspE … Ap r ; pPROBE-AT containing a dspE-gfp transcriptional fusion Zeng et al. 2010 pPhrpA … Ap r ; pPROBE-AT containing a hrpA-gfp transcriptional fusion Yang et al. 2008 pPhrpL … Ap r ; pPROBE-AT containing a hrpL-gfp transcriptional fusion Yang et al. 2008 pPhrpN … Ap r ; pPROBE-AT containing a hrpN-gfp transcriptional fusion Yang et al. 2008 pPrsmB … Ap r ; pPROBE-AT containing a rsmB-gfp transcriptional fusion Zeng et al. 2012 pPopgGH … Ap r ; pPROBE-AT containing a opgGH-gfp transcriptional fusion This study pWM91 … Ap r ; sucrose-based counter-selectable plasmid Metcalf et al. 1996 p91DopgH … Ap r ; plasmid pWM91 carrying a deleted opgH gene This study p91DrcsB … Ap r ; plasmid pWM91 carrying a deleted rcsB gene This study p91opgGHis … Ap r ; pWM91 with a 6×His epitope sequence tagged to the C terminus of OpgG "
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