GSE115811
Danger signals activate the innate immune system of a filamentous fungus during regeneration
The ability to respond to injury is a biological process conserved across kingdoms, which in some cases results in regeneration of an organism's lost part or structure.  Due to their immobility, multicellular fungi are prey to a variety of predators and are therefore constantly exposed to mechanical damage. Nevertheless, our current knowledge of how fungi respond to injury is scarce. Activation of injury responses and regeneration relies on the detection of danger or alarm signals known as Danger- or Damage-Associated Molecular Patterns. We show that Ca2+ influxes and extracellular ATP, two such signals, together with Mitogen-Activated Protein Kinases, play a key role in the control of hyphal regeneration in the filamentous fungus Trichoderma atroviride. We further show that these signaling cascades activate major transcriptional changes early after injury. We identified a set of regeneration genes related to cell signaling, stress responses, regulation of transcription, ribosome biogenesis/translation, replication and DNA repair. We uncovered the activation of an innate immune response, including HET domain genes, until now only known to participate in vegetative incompatibility. We show that fungal and animal regeneration share danger-signals, signaling cascades, and the activation of an immune system, challenging the current notion of the evolution of this process. Overall design: Differential expression analysis of 8 conditions for triplicate. In all cases, an injured control without chemical treatment and a control without injury were included, and three biological replicates were analyzed per strain and/or treatment.