The gene coding for a new transcription factor (ftf1) of Fusarium oxysporum is only expressed during infection of common bean

We report the isolation and analysis of the gene encoding ftf1 (Fusarium transcription factor 1), a previously undescribed putative transcription factor from highly virulent strains of Fusarium oxysporum f.sp. phaseoli that is transcribed specifically during early stages of infection of its host common bean (Phaseolus vulgaris L.). The predicted 1080 amino acid ftf1 protein contains a Zn(II)2-Cys6 binuclear cluster DNA-binding motif. ftf1 expression during axenic growth in culture was not detected by either Northern or RT-PCR. On the contrary, in planta transcription of ftf1 is increased about 24 h after plant inoculation, as detected by real-time RT-PCR. This result suggests that ftf1 has a role in the establishment of the fungus within the plant and/or the progress of the disease. Multiple copies of ftf1 are present in highly virulent strains of F. oxysporum f.sp. phaseoli.