title: A Trichoderma atroviride stress-activated MAPK pathway integrates stress and light signals.
abstract: Cells possess stress-activated protein kinase (SAPK) signalling pathways, which are activated practically in response to any cellular insult, regulating responses for survival and adaptation to harmful environmental changes. To understand the function of SAPK pathways in T. atroviride, mutants lacking the MAPKK Pbs2 and the MAPK Tmk3 were analysed under several cellular stresses, and in their response to light. All mutants were highly sensitive to cellular insults such as osmotic and oxidative stress, cell wall damage, high temperature, cadmium, and UV irradiation. Under oxidative stress, the Tmk3 pathway showed specific roles during development, which in conidia are essential for tolerance to oxidant agents and appear to play a minor role in mycelia. The function of this pathway was more evident in Δpbs2 and Δtmk3 mutant strains when combining oxidative stress or cell wall damage with light. Light stimulates tolerance to osmotic stress through Tmk3 independently of the photoreceptor Blr1. Strikingly, photoconidiation and expression of blue light regulated genes was severally affected in Δtmk3 and Δpbs2 strains, indicating that this pathway regulates light responses. Furthermore, Tmk3 was rapidly phosphorylated upon light exposure. Thus, our data indicate that Tmk3 signalling cooperates with the Blr photoreceptor complex in the activation of gene expression.
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV-Irapuato, Irapuato, México.|Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Querétaro, Querétaro, México.
authors.forename: Edgardo Ulises
authors.initials: EU
authors.lastname: Esquivel-Naranjo
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV-Irapuato, Irapuato, México.
authors.forename: Mónica
authors.initials: M
authors.lastname: García-Esquivel
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV-Irapuato, Irapuato, México.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Medina-Castellanos
authors.affiliation: Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Querétaro, Querétaro, México.
authors.forename: Víctor Alejandro
authors.initials: VA
authors.lastname: Correa-Pérez
authors.affiliation: Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Querétaro, Querétaro, México.
authors.forename: Jorge Luis
authors.initials: JL
authors.lastname: Parra-Arriaga
authors.affiliation: Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Querétaro, Querétaro, México.
authors.forename: Fidel
authors.initials: F
authors.lastname: Landeros-Jaime
authors.affiliation: Unit for Basic and Applied Microbiology, Faculty of Natural Sciences, Autonomous University of Querétaro, Querétaro, México.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Cervantes-Chávez
authors.affiliation: Laboratorio Nacional de Genómica para la Biodiversidad, CINVESTAV-Irapuato, Irapuato, México.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Herrera-Estrella
mesh_terms: D002473:Cell Wall / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D008027:Light; D048055:Mitogen-Activated Protein Kinase 8 / Q000235:genetics / Q000378:metabolism*; D020929:Mitogen-Activated Protein Kinase Kinases / Q000235:genetics / Q000378:metabolism* / Q000528:radiation effects; D025282:Mycelium / Q000254:growth & development / Q000378:metabolism; D009997:Osmotic Pressure; D010766:Phosphorylation; D015398:Signal Transduction / Q000235:genetics / Q000528:radiation effects; D013172:Spores, Fungal / Q000378:metabolism / Q000528:radiation effects; D013312:Stress, Physiological; D014242:Trichoderma / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D005656:Fungal Proteins; D048055:Mitogen-Activated Protein Kinase 8; D020929:Mitogen-Activated Protein Kinase Kinases