The entomopathogenic fungi are subject to regulation system known as signal transduction that regulates the expression of the different genes required for each life stage, first comprising cuticle adhesion and degradation, later the survival in the hemolymph, and finally the fungal growth in soils. There are two signal-transduction mechanisms identified in the entomopathogenic fungi: mitogen-activated protein kinases (MAPK) and protein kinase A (PKA) dependent to cAMP pathway together with regulatory G protein signaling; both pathways participate in activation of genes linked to virulence for certain environments and hosts such as adhesion, formation of appressorium and penetration pegs, synthesis of cuticle-degrading enzymes, survival in hemolymph to evade insect immune responses, and osmolarity changes. Also, activating well-defined gene sets involved in entomopathogenic fungal survival on non-insect substrates as saprophytes or root colonizer utilized the nutrients present in root exudates, facilitating entomopathogenic fungi to act as endophytes.

Key words: Entomopathogenic fungi, signal transduction, mitogen-activated protein kinases (MAPK), protein kinase A (PKA).