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Identification of Salmonella enterica genes that are involved in the growth and survival of the pathogen on post-harvest lettuce at room temperature and under cold stress, and in soft rot lesions.
APPROACH: Recombinase In Vitro Expression Technology (RIVET) will be used to identify genes that are upregulated in Salmonella after inoculation onto cut lettuce held at room temperature or at 10?C. Salmonella genes differentially regulated in cut lettuce co-inoculated with a soft rot plant pathogen will be identified by microarray analysis of gene expression profiling. Mutants in candidate genes will be constructed and comparatively tested against the parental strain for growth and survival on lettuce under the above conditions. Documents Reimbursable with BARD. 425 Log 29422.
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PROGRESS: 2006/10 TO 2007/09<BR>
Progress Report Objectives (from AD-416) Identification of Salmonella enterica genes that are involved in the growth and survival of the pathogen on post-harvest lettuce at room temperature and under cold stress, and in soft rot lesions. Approach (from AD-416) Recombinase In Vitro Expression Technology (RIVET) will be used to identify genes that are upregulated in Salmonella after inoculation onto cut lettuce held at room temperature or at 10ºC. Salmonella genes differentially regulated in cut lettuce co-inoculated with a soft rot plant pathogen will be identified by microarray analysis of gene expression profiling. Mutants in candidate genes will be constructed and comparatively tested against the parental strain for growth and survival on lettuce under the above conditions. Documents Reimbursable with BARD. 425 Log 29422. Significant Activities that Support Special Target Populations This report serves to document research conducted under a Specific Cooperative Agreement between ARS and United States-Israel Binational Agricultural Research and Development Fund (BARD). Additional details of research can be found in the report for the parent project, 5325-42000- 044-00D, Molecular Microbiology and Control of Enteric Pathogens that Contaminate Fresh Produce. Gene expression profile of Salmonella while in soft rot lesions on leafy greens was determined. Expression of candidate genes further measured by QRT-PCR. Mutants in specific Salmonella metabolic pathways that are upregulated in soft rot lesions were tested on diseased leaves and provided evidence of the role of these pathways in the colonization of rot-affected leaves by the food-borne pathogen.