Wanted: pathogenesis-related marker molecules for Fusarium oxysporum.

Although Fusarium oxysporum pathogens cause severe wilts in about 80 botanical species, the mechanisms of pathogenicity and symptom induction are poorly understood. Knowledge about the genetic and biochemical pathways involved in the pathogenesis of F. oxysporum would be invaluable in getting targets for both fungicide development and search for biocontrol agents. In this respect, we described the main approaches that have been developed to identify some mechanisms underlying the pathogenesis of F. oxysporum. During the last decades, the potential functions triggering of F. oysporum pathogenicity have mainly been investigated by comparing soilborne pathogenic strains with nonpathogenic ones with regards to the analysis of the pre- and infection stages and of the resulting plant-fungus interactions. The relatively recent progress in the molecular biology of this fungus has allowed complementary approaches to be developed in order to identify key factors involved in F. oxysporum pathogenicity. Screening mutants of F. oxysporum for loss of virulence led to the successful identification of some pathogenesis-related factors, such as hydrophobicity or attachment of germlings. Taken together, the strategies described above support the idea that changes in fungal metabolism is also of importance in triggering of F. oxysporum pathogenesis.