Signal Transduction Cascades Regulating Differentiation and Virulence in Botrytis cinerea

Fungi are eukaryotic organisms that are more closely related to animals than to plants and algae, and therefore fungal cells share important features with mammalian cells. This is perhaps most apparent in the signaling cascades that mediate the communication between environmental signals and the cellular machinery regulating developmental programs. Conserved signaling systems present in all eukaryotes, from yeast to mammals, comprise cAMP and Ca2+ as second messengers, and further include Ras superfamily proteins and mitogen-activated (MAP) kinases. Apart from that, filamentous fungi evolved a light response system allowing for use of light and its absence, respectively, as environmental cues to control development and secondary metabolism. Recent progress in understanding the regulatory networks in B. cinerea by functional characterization of key components of the signal transduction pathways is summarized with emphasis on their impact on differentiation and virulence.