THE ptsP GENE CONTROLS THE BACTERIOCIN PRODUCTION AND ROOT COLONIZATION IN P. fluorescens SF39a

AGUSTINA GODINO; ANALÍA PRÍNCIPE; VIRGINIA RIGO; EDGARDO JOFRÉ; GLADYS MORI; SONIA FISCHER

Buenos Aires

Congreso; Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2013

Bacteriocins are proteinaceous toxins that can kill closely related species, providing the producer better access to limited resources. Rhizosphere isolate P. fluorescens SF39a secretes a bacteriocin active against P. fluorescens CTR212. The aim of this work was to identity of genetic determinants involved in the production or regulation of this bacteriocin. Previously, a miniTn5Km1 mutant (P. fluorescens 451) affected in bacteriocin production was obtained. In P. fluorescens 451, the transposon was inserted into ptsP gene which encodes a phosphoenolpyruvate phosphotransferase of the phosphotransferase system PTSNtr. In this work, heterologous complementation studies were performed. The ptsP gene from P. fluorescens Pf01 restored the production of bacteriocin, indicating that the observed phenotype in the mutant 451 was caused by inactivation of the ptsP gene. The protease and pyoverdine production, motility, biofilm formation and ability to colonize the rhizosphere of wheat were analyzed in the strain 451. This mutant showed a decrease in biofilm formation and protease production, and an increase in swarming motility and pyoverdine production. In addition, this mutant was less competitive than wild-type strain in the wheat rhizosphere. These results suggest that a mutation in the ptsP gene affects a variety of phenotypes that can influence bacterial fitness in the environment