title: BLR-1 and BLR-2, key regulatory elements of photoconidiation and mycelial growth in Trichoderma atroviride.
abstract: In fungi, phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. Trichoderma atroviride, a fungus used in biological control, sporulates in a synchronized manner following a brief pulse of blue light. Due to its apparent simplicity, this response was chosen for pursuing photoreceptor isolation. Two genes were cloned, blue-light regulators 1 and 2 (blr-1 and blr-2), similar to the Neurospora crassa white-collar 1 and 2, respectively. The BLR-1 protein has all the characteristics of a blue-light photoreceptor, whereas the structure of the deduced BLR-2 protein suggests that it interacts with BLR-1 through PAS domains to form a complex. Disruption of the corresponding genes demonstrated that they are essential for blue-light-induced conidiation. blr-1 and blr-2 were also shown to be essential for the light-induced expression of the photolyase-encoding gene (phr-1). Mechanical injury of mycelia was found to trigger conidiation of T. atroviride, a response not described previously. This response was not altered in the mutants. A novel effect of both red and blue light on mycelial growth was found involving another light receptor, which is compensated by the BLR proteins.
authors.affiliation: Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.|Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, Apartado postal 187, Guanajuato 36050, Mexico.
authors.forename: Sergio
authors.initials: S
authors.lastname: Casas-Flores
authors.affiliation: Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Rios-Momberg
authors.affiliation: Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.
authors.forename: Martha
authors.initials: M
authors.lastname: Bibbins
authors.affiliation: Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, Apartado postal 187, Guanajuato 36050, Mexico.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ponce-Noyola
authors.affiliation: Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Herrera-Estrella
mesh_terms: D000595:Amino Acid Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000235:genetics; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000096:biosynthesis / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005809:Genes, Regulator; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D025282:Mycelium / Q000235:genetics / Q000254:growth & development*; D020283:Photoreceptors, Microbial / Q000235:genetics*; D018524:Phototropism / Q000235:genetics; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000235:genetics; D014242:Trichoderma / Q000235:genetics / Q000254:growth & development*
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D020283:Photoreceptors, Microbial; D014157:Transcription Factors; C105589:wc-1 protein, Neurospora crassa; C103772:white collar 2 protein, Neurospora; D004255:Deoxyribodipyrimidine Photo-Lyase