Exploring effector profiles of soil-borne plant pathogenic fungi

Soil-borne fungi such as Verticillium dahliae and Fusarium oxysporum employ diverse infection strategies to colonize their plant hosts and cause devastating vascular diseases. A central element of their pathogenicity lies in the secretion of effector proteins that manipulate host immunity either directly, by targeting plant immune components, or indirectly, by interfering with the plant’s ability to recruit beneficial microbiota that enhance defence. This thesis investigates these dual strategies through the functional and structural analysis of two representative effectors. The D effector, initially identified in V. dahliae, exemplifies a direct mode of manipulation by promoting host defoliation and virulence through immune system interference. Conversely, the Av2 effector, recently recharacterized as an antimicrobial protein, illustrates an indirect strategy by suppressing the recruitment of protective Pseudomonas spp. and other beneficial microbes. Integrating genomic mining with protein expression, structural elucidation, and host interaction studies provides new insights into how fungal pathogens co-opt plant immune systems and microbiota to establish infection. These findings pave the way for novel disease management strategies that exploit effector biology to enhance crop resistance or disrupt pathogen virulence mechanisms.