Mechanism of Virulence in Fungal Pathogens with Diverse Modes of Living.

Fungi are the most versatile group of eukaryotes, with majority of them thriving as saprophytes. Only a small proportion of the fungi has been identified as phytopathogenic that cause serious diseases in crop plants. While saprophytic fungi survive on dead or decomposing organic material as their source of nutrients, pathogenic fungi lead a parasitic life in their hosts. The fungal phytopathogens are grouped as biotrophs, necrotrophs, and hemibiotrophs based on their mode of nourishment from their hosts. Though studies have revealed the nature of infection and lifestyle of these three groups of fungi in their respective hosts, the mechanism underlying their virulence is not fully understood. To understand the mechanism of fungal virulence, the present study reviews the previous findings from important biotrophic and necrotrophic pathogenic fungi that infect crop plants, in order to comprehend their virulence mechanisms. In addition, the review also highlights the virulence of members of the genus Cladosporium, which exhibits diverse modes of survival, such as biotroph and hemibiotroph, indicating their versatility to establish an effective and competitive sustenance mechanism in their hosts.