Molecular Plant-Microbe Interactions (2010) 23, 273-282

J.T. Noel, J. Joy, J.N. Smith, M. Fatica, K.R. Schneider, B.M.M. Ahmer and M. Teplitski (2010)
Salmonella SdiA recognizes N-acyl homoserine lactone signals from Pectobacterium carotovorum in vitro, but not in a bacterial soft rot
Molecular Plant-Microbe Interactions 23 (3), 273-282
Abstract: Genomes of Salmonella enterica isolates, including those linked to outbreaks of produce-associated gastroenteritis, contain sdiA, which encodes a receptor of N-acyl homoserine lactones (AHL). AHL are the quorum-sensing signals used by bacteria to coordinately regulate gene expression within -their populations. Because S. enterica does not produce its own AHL, SdiA is hypothesized to function in the interspecies cross-talk with AHL-producing bacteria. Under laboratory conditions, S. enterica responded to AHL from phytobacteria by upregulating expression of srgE. AHL-dependent expression of srgE required a functional sdiA. Essentially, no sdiA-dependent resolution of the srgE recombinase-based (RIVET) reporter was observed inside a soft rot formed on a tomato by an AHL-producing strain of Pectobacterium carotovorum. The results of the control experiments suggest that sdiA is not expressed inside tomato, pepper, green onion, or carrot affected by the soft rot, and the lack of sdiA expression in planta prevents Salmonella spp. from responding to AHL. Despite its inability to detect and respond to AHL during colonization of soft rots, S. enterica reached higher final cell numbers inside a tomato soft rot compared with its growth in intact tomato fruit. The synergistic effect was the strongest under the conditions that are typical for the Florida fall/winter production season.
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Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pectobacterium carotovorum	Carrot (Daucus carota)	U.S.A. (SE)
	Pectobacterium carotovorum	Green pepper/chilli (Capsicum)	U.S.A. (SE)
	Pectobacterium carotovorum	Tomato (Solanum lycopersicum)	U.S.A. (SE)
	Pectobacterium carotovorum	Onion/garlic/leek (Allium)	U.S.A. (SE)