Submitted to: American Phytopathology Society
Publication Type: Abstract Only
Publication Acceptance Date: 8/7/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The two-component regulatory gene pair gacS (formerly lemA) and gacA has been shown to regulate a diverse set of phenotypes in Pseudomonas syringae pv. syringae B728a, including the production of extracellular protease, syringomycin, and homoserine lactone, as well as field fitness and disease manifestation on bean. Recent results have demonstrated that the salA gene is a positive regulator of a subset of the Gac regulon, being involved in syringomycin production and the formation of disease lesions. We have undertaken further delineation of this regulon, using a Tn5lacZ reporter system to systematically detect genes whose expression are differentially affected by gacA. Both positively and negatively gacA-affected insertions have been isolated. DNA sequence analysis identified insertion sites in alginate, rhamnolipid, and rotamase loci, among others, as well as in several genes of unknown function. The results are suggestive of previously unanticipated avenues for future experimentation.