Delivering the goods: Fungal secretion modulates virulence during host–pathogen interactions

Fungi secrete a variety of compounds that have wide ranging effects on society and govern the outcome of host–pathogen interactions. The secreted products range from powerful toxins and carcinogens, to beneficial compounds such as ethanol used in common commercial practices, and the ‘wonder drug’ penicillin. Much research in the past 50 y has focused on identifying the genes and their functions relating to the fungal secretome. Recent advances into the mechanisms by which phytopathogenic fungal secretion systems function and modulate virulence have broad implications for the agricultural and biotechnological industries. In this review, we focus on secretion mechanisms in phytopathogenic fungi with examples from key plant–pathogen systems. Current progress and knowledge gaps regarding secretion pathways and their regulation are discussed. We highlight possible approaches to using novel molecular techniques to generate alternative control methods to synthetic pesticides.