Evidence for signalling between the phytopathogenic fungus Pythium ultimum and Pseudomonas fluorescens F113: P. ultimum represses the expression of genes in P. fluorescens F113, resulting in altered ecological fitness

The expression of Pseudomonas fluorescens F113 genes in the presence and absence of the phytopathogenic fungus Pythium ultimum was monitored to determine the ability of the fungus to alter genetic expression in Pseudomonas. Results indicate a repression of several gene clusters in P. fluorescens F113 resulting in a reduction of ecological fitness in this strain of bacteria.