BLR-1 and BLR-2, key regulatory elements of photoconidiation and mycelial growth in Trichoderma atroviride.
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.
Casas-Flores
Sergio
S
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.
Rios-Momberg
Mauricio
M
Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.
Bibbins
Martha
M
Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.
Ponce-Noyola
Patricia
P
Instituto de Investigación en Biología Experimental, Facultad de Química, Universidad de Guanajuato, Apartado postal 187, Guanajuato 36050, Mexico.
Herrera-Estrella
Alfredo
A
Departamento de Ingeniería Genética de Plantas, CINVESTAV Unidad Irapuato, Apartado postal 629, Irapuato 36500, Mexico.
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*
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