Functional genomics analysis of the Pseudomonas fluorescens PICF7/Olea europaea interaction: identification of ESTs during olive roots colonization by an endophytic biocontrol strain.

Within an integrated disease control strategy to promote long-term protection against Verticillium wilt of olive (Olea europaea L.), we aimed to elucidate the genetic and molecular processes taking place during the colonization of olive roots by Pseudomonas fluorescens PICF7, an effective biocontrol agent against VWO. SSH methodology and transcriptome analysis enabled the identification of putative genes differentially expressed such as several enzymes related to biosynthesis of plant hormones (i.e. lipoxygenase, chorismate synthase) and of phenylpropanoids compounds (i.e. phenylalanine ammonia lyase, cinnamyl-alcohol dehydrogenase). Interestingly, among the transcriptionally up- or down-regulated genes, diverse transcription factors implicated in plant signaling pathways for both biotic and abiotic stimulus response were also identified.