The Importance of Fungi
Medical and agricultural importance of fungi
Fungi have a devastating impact on agriculture and human health. Crop production, worth billions of € per year is destroyed by fungal diseases. Human fungal infections have severe consequences on the growing number of immuno-compromised patients, with high mortality rates. At least as many people die each year from fungal infections as die from tuberculosis or malaria.
Resistance against antifungals, especially azoles, is rising. Global markets in agricultural fungicides and medical antifungals are increasing steadily and in 5 years these will top €30 billion per year. However, only a very limited number of novel antifungals have been introduced to the market in recent years. Just four cellular targets are currently available for human antifungal drugs and the last one was discovered in 1974.
Fungal cell tropisms
Fungi cell polarity and directed growth (tropism) are fundamental biological processes. Most fungi are dependent on these processes because they grow as polarised filaments called hyphae, whose growth and development are governed by physical and chemical cues from the environment. Such cues include surface-contact, light, nutrients, mating partners, host organisms, or ‘self’ hyphae from within the fungal colony. The capacity to re-orient hyphal tip growth in response to external signals forms the basis of the saprotropic, symbiotic and parasitic lifestyles of fungi. For example, dimorphic transitions and directed hyphal growth are intimately associated with virulence in fungal pathogens. The cellular components that control these morphogenetic decisions therefore play key roles in fungal adaptation to environmental change and the invasion stages of infectious growth.
What is the ‘Fungal Brain’?
Extensive background work has led to the emerging concept of a “fungal brain”, which integrates exogenous and endogenous signals to determine the shape and direction of hyphae, both at the levels of the individual cell and of the fungal colony. However, in spite of the universal importance of these processes, surprisingly little is known about their genetic and cellular bases. FungiBrain will focus on the key components of signalling networks involved in regulating polarized and directed cell growth, which represent a rich and largely untapped source of new antifungal drug targets to be exploited in novel assays for the screening of inhibitors.