Comparative analysis of PR gene expression in tomato inoculated with virulent Fusarium oxysporum f. sp lycopersici and the biocontrol strain F. oxysporum Fo47

Non-pathogenic strains of Fusarium oxysporum have the capacity to protect plants against wilt induced by pathogenic strains of F. oxysporum. Among the mechanisms involved in this protection, induced systemic resistance has been demonstrated by using a split-root method. The aim of this study was to follow the accumulation kinetics of transcripts encoding 5 PR proteins in roots and leaves of tomato inoculated with a pathogenic or a protective strain in comparison to non-inoculated control. Moreover quantification of transcripts was assessed by real-time RT-PCR in cell cultures inoculated with the pathogenic or the protective strain. Results showed a lower expression of PR encoding genes in the plants or cells inoculated with the protective strain. These results showing that there is no increased accumulation of PR proteins after inoculation of the protective strain, suggest that accumulation could follow inoculation of the pathogen. Priming the plant defense reaction could be the mode of action of Fo47. (c) 2008 Elsevier Ltd. All rights reserved.