Nutrient sensing and acquisition in fungi: mechanisms promoting pathogenesis in plant and human hosts

Fungal pathogens destroy our crops and cause hazardous human infections, therefore threatening our health and food security. The ability of fungal pathogens to sense and respond to dynamic host microenvironments enables the establishment and progression of disease. Sensing nutritional cues is vital throughout fungal infection of either plants or mammals: enabling the pathogen to invade, adapt and survive in the face of host immunity. Acquiring nutrients from their host for energy, growth and repair is also essential to a fungal pathogen's success. Cell-surface proteins embedded in the fungal plasma membrane sense and transport host macro- and micronutrients, including carbon and nitrogen sources and minerals such as iron and zinc. Using examples from model crop (Fusarium graminearum, Magnaporthe oryzae and Ustilago maydis) and human (Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans) pathogens we review the nutrient sensing and transporting roles of fungal cell-surface receptor, transporter and transceptor proteins, and their importance to plant and human fungal disease. We discuss how their cellular localisation, central role in cell signalling and importance to disease makes these fungal cell-surface proteins candidates in the search for new strategies to control fungal diseases, while highlighting the areas where further research is needed to make this possible.