Insights into the distinct cooperation between the transcription factor Clp and LeDSF signaling in the regulation of antifungal factors in Lysobacter enzymogenes OH11

Abstract The DSF (Diffusible Signal Factor) signaling and transcription factor Clp play key roles in regulating a diverse range of physiology in the phytopathogen Xanthomonas campestris pv. campestris . However, their functional relationship in other bacteria is little addressed. Here, we presented evidences to show that there are distinct differences in signaling connection between the Clp and Le DSF pathways in Lysobacter enzymogenes , which is a Gram-negative bacterium with remarkable antifungal activity. We found that Clp was a bona fide regulator downstream of the Le DSF signaling in modulating HSAF biosynthesis. However, regulations of Clp on the other two processes, namely, the extracellular protease and chitinase productions, as well as twitching motility, were found to be independent of the Le DSF signaling. These distinct behaviors of Clp were further validated by a comprehensive transcriptomic analysis. Taken together, the present study expands our understanding on the connection between the DSF signaling and Clp signaling pathways in different bacteria.