Photomorphogenesis in the hypogeous fungus Tuber borchii: isolation and characterization of Tbwc-1, the homologue of the blue-light photoreceptor of Neurospora crassa.
Truffles form a group of plant-symbiotic Ascomycetes whose hypogeous life cycle is poorly understood. Here we present initial evidence for the influence of light on Tuber borchii mycelial growth and the identification and cloning of a gene, Tbwc-1, homologous to a blue-light photoreceptor of Neurospora crassa. Blue-light irradiation of T. borchii colonies inhibits their apical growth. It also alters apical growth in N. crassa. In Neurospora, the response is controlled by a nuclear photoreceptor, NcWC-1 (White Collar-1), which consists of a sensor domain (LOV) and a transcriptional factor moiety. We isolated a gene (Tbwc-1) whose deduced amino acid sequence shows a high similarity and colinearity of domains with NcWC-1, except for the polyglutamine regions. As previously found in Neurospora, Tbwc-1 mRNA is under light control and its steady state level increases upon irradiation. In silico analysis of the TbWC-1 sensor domain (LOV) supports the hypothesis that TbWC-1 is a photoreceptor, while the absence of the two polyglutamine regions involved in transcriptional activation in Neurospora suggests that this function in Tuber could be lost.
Ambra
R
R
Dipartimento di Biotecnologie Cellulari ed Ematologia c/o V Clinica Medica, Policlinico Umberto I, Università La Sapienza, viale Regina Elena 324, Rome 00161, Italy.
Grimaldi
B
B
Zamboni
S
S
Filetici
P
P
Macino
G
G
Ballario
P
P
D000595:Amino Acid Sequence; D001203:Ascomycota / Q000166:cytology / Q000235:genetics* / Q000254:growth & development*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000302:isolation & purification; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008027:Light; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009024:Morphogenesis; D025282:Mycelium / Q000235:genetics / Q000254:growth & development; D009492:Neurospora crassa / Q000235:genetics; D020283:Photoreceptors, Microbial / Q000235:genetics / Q000302:isolation & purification; D011099:Polyglutamic Acid / Q000235:genetics; D017434:Protein Structure, Tertiary; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification; D014158:Transcription, Genetic
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D020283:Photoreceptors, Microbial; D012331:RNA, Fungal; D012333:RNA, Messenger; D014157:Transcription Factors; C105589:wc-1 protein, Neurospora crassa; D011099:Polyglutamic Acid