Crucial factors of the light perception machinery and their impact on growth and cellulase gene transcription in Trichoderma reesei.
In Trichoderma reesei light stimulates transcription of cellulase genes and this regulation has been found to occur, at least in part, through the protein ENVOY. Here we analyzed the role of the BLR photoreceptor complex (BLR1/BLR2) in photoconidiation and the regulation of gene expression. Both responses were dependent on both BLR proteins. Analyses of Deltablr1, Deltablr2 and Deltaenv1 mutants showed that the BLR proteins regulate growth under illumination. Analysis of env1 mutant strains indicated that ENVOY allows the fungus to tolerate continuous exposure to light, damped the capacity of Trichoderma to perceive changes in light intensity, and suggested that it participates in a negative regulatory feedback. Its activity as repressor establishes a period of insensitivity to a second light treatment. Interestingly, the stimulation of cellulase gene expression by light was also modulated by both blr1 and blr2, indicating a key role of the BLR proteins in this pathway.
Laboratorio Nacional de Genómica para Biodiversidad, and Departamento de Ingeniería Genética de Plantas, CINVESTAV Irapuato, Apartado Postal 629, Irapuato 36821, Mexico.
Francisco
F
Castellanos
Monika
M
Schmoll
Pedro
P
Martínez
Doris
D
Tisch
Christian P
CP
Kubicek
Alfredo
A
Herrera-Estrella
Edgardo Ulises
EU
Esquivel-Naranjo
D002480:Cellulase / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000528:radiation effects*; D015966:Gene Expression Regulation, Fungal / Q000528:radiation effects; D008027:Light; D020283:Photoreceptors, Microbial / Q000235:genetics / Q000378:metabolism*; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects; D014242:Trichoderma / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism / Q000528:radiation effects*
D005656:Fungal Proteins; D020283:Photoreceptors, Microbial; D002480:Cellulase