Genome-wide identification and expression analysis of homeobox genes in Fusarium oxysporum f. sp. lycopersici

Tomato fusarium wilt, caused by Fusarium oxysporum f. sp. lycopersici, is a widespread disease occurring in majority of tomato cultivation areas worldwide. Homeobox transcription factor-encoding genes play a vital role in fungal vegetative growth and morphology, but their role in fungal pathogenicity is largely unknown. In this study, 25 homeobox genes (FoHOX 1-25) were identified in the F. oxysporum f. sp. lycopersici genome, using bioinformatics methods. Phylogenetic analysis showed that the FoHOX genes were divided into four groups; furthermore, these genes were unevenly distributed on six chromosomes and qRT-PCR analysis revealed that all 25 were differentially expressed in the host during plant-pathogen interaction. During our study, expression levels of the respective genes in tomato seedlings increased from day one to seven, and most genes showed a decreasing expression trend by day ten. In conclusion, these results may provide a useful foundation for functional analyses of homeobox transcription factor genes involved in the pathogenicity, and regulation of plant immunity.