Deletion of the Transcription Factor Gene and a Point Mutation in the F-Box Protein Gene Confer Sorbose Resistance in .

L-Sorbose induces hyperbranching of hyphae, which results in colonial growth in The gene, which encodes a glucose sensor that acts in carbon catabolite repression (CCR), has been identified as a sorbose resistance gene. In this study, we found that the deletion mutant of , which encodes an AmyR-like transcription factor that acts in CCR, displayed sorbose resistance. In contrast, the deletion mutants of other CCR genes, such as a hexokinase (), an AMP-activated S/T protein kinase (), and a transcription factor (), showed no sorbose resistance.

A partial photoreactivation defect phenotype is not due to unrepaired ultraviolet-induced pyrimidine dimers in ultraviolet-sensitive mutants of Neurospora crassa.

Photoreactivation is a mechanism in which photolyase directly repairs either cyclobutane pyrimidine dimers (CPDs) or (6-4) photoproducts [(6-4) PPs] caused by ultraviolet (UV) light. In the filamentous fungus Neurospora crassa, some UV-sensitive mutants such as mus-44 have been reported to exhibit a partial photoreactivation defect (PPD) phenotype, but its mechanism has not been elucidated for a long time. In this study, the N.

Involvement of MAK-1 and MAK-2 MAP kinases in cell wall integrity in Neurospora crassa.

Among three MAPK disruptants of Neurospora crassa, Δmak-1 was sensitive and Δmak-2 was hypersensitive to micafungin, a beta-1,3-glucan synthase inhibitor, than the wild-type or Δos-2 strains. We identified six micafungin-inducible genes that are involved in cell wall integrity (CWI) and found that MAK-1 regulated the transcription of non-anchored cell wall protein gene, ncw-1, and the beta-1,3-endoglucanase gene, bgt-2, whereas MAK-2 controlled the expression of the glycosylhydrolase-like protein gene, gh76-5, and the C4-dicarboxylate transporter gene, tdt-1. Western blotting analysis revealed that, in the wild-type strain, MAK-1 was constitutively phosphorylated from conidial germination to hyphal development.

Deletion and expression analysis of beta-(1,3)-glucanosyltransferase genes in Neurospora crassa.

GPI(glycosylphosphatidylinositol)-anchored beta-(1,3)-glucanosyltransferases play an active role in cell wall biosynthesis in fungi. Neurospora crassa has 5 putative beta-(1,3)-glucanosyltransferase genes, namely, gel-1, gel-2, gel-3, gel-4, and gel-5, in its genome. Among them, the gel-3 gene is constitutively expressed at the highest level in growing hyphae, whereas gel-1 is expressed at the lowest level.

An AP-1-like transcription factor, NAP-1, regulates expression of the glutathione S-transferase and NADH:flavin oxidoreductase genes in Neurospora crassa.

AP-1-like transcription factors play crucial roles in oxidative stress responses in yeast and filamentous fungi. The deletion of an AP-1-like transcription factor gene, nap-1, in Neurospora crassa slightly increased its sensitivity to oxidative stressors, including menadione. Microarray and quantitative real-time reverse transcriptase-PCR analyses were employed to identify menadione-inducible genes (migs) and the roles of NAP-1 in their regulation.

Genotyping of benzimidazole-resistant and dicarboximide-resistant mutations in Botrytis cinerea using real-time polymerase chain reaction assays.

Botrytis cinerea, an economically important gray mold pathogen, frequently exhibits multiple fungicide resistance. A fluorescence resonance energy transfer-based real-time polymerase chain reaction assay has been developed to detect benzimidazole- and dicarboximide-resistant mutations. Three benzimidazole-resistant mutations-(198)Glu to Ala (E198A), F200Y, and E198K-in beta-tubulin BenA were detected using a single set of fluorescence-labeled sensor and anchor probes by melting curve analysis.

A Point Mutation in the Two-Component Histidine Kinase BcOS-1 Gene Confers Dicarboximide Resistance in Field Isolates of Botrytis cinerea.

ABSTRACT Partial DNA fragments of Botrytis cinerea field isolates encoding the putative osmosensor histidine kinase gene (BcOS1) were cloned by polymerase chain reaction amplification and the predicted amino acid sequences were compared between dicarboximide-sensitive and resistant field isolates. The predicted BcOS1p is highly homologous to osmosensor histidine kinase OS1p from Neurospora crassa including the N-terminal six tandem repeats of approximately 90 amino acids. Four dicarboximide-resistant isolates of B.

Genetic analysis of the Neurospora crassa RAD14 homolog mus-43 and the RAD10 homolog mus-44 reveals that they belong to the mus-38 pathway of two nucleotide excision repair systems.

Saccharomyces cerevisiae Rad14 and Rad10 proteins are essential for nucleotide excision repair (NER). Rad14 is a UV-damaged DNA binding protein and Rad10 is a structure-specific endonuclease that functions in a complex with Rad1. In this study, we identified and characterized the RAD14 and RAD10 homolog genes in Neurospora crassa, which we named mus-43 and mus-44, respectively.

OS-2 mitogen activated protein kinase regulates the clock-controlled gene ccg-1 in Neurospora crassa.

OS-2 MAP kinase is involved in osmoadaptation in Neurospora crassa. Clock-controlled genes ccg-1, bli-3, and con-10 were induced by osmotic stress in an OS-2 dependent manner. In contrast, osmotic stress did not affect the expression of clock genes frq, wc-1, and wc-2 or of clock-controlled genes ccg-2 and bli-4.

Involvement of OS-2 MAP kinase in regulation of the large-subunit catalases CAT-1 and CAT-3 in Neurospora crassa.

Neurospora crassa has four catalase genes--cat-1, cat-2, cat-3, and ctt-1/cat-4. cat-1 and cat-3 encode two fungal-specific large-subunit catalases CAT-1 and CAT-3 normally produced in conidia and growing hyphae, respectively. cat-2 encodes CAT-2 catalase-peroxidase normally produced in conidia.

Identification of OS-2 MAP kinase-dependent genes induced in response to osmotic stress, antifungal agent fludioxonil, and heat shock in Neurospora crassa.

Two-component signal transduction comprising of OS-1 (histidine kinase), OS-4 (MAPKK kinase), OS-5 (MAPK kinase), and OS-2 (MAP kinase) plays an important role in osmotic regulation in Neurospora crassa. To identify the genes regulated downstream of OS-2 MAP kinase, quantitative real-time RT-PCR analysis was conducted in selected genes based on Hog1 MAP kinase regulated genes in yeast. In response to osmotic stress and fludioxonil, expression of six genes that for glycerol synthesis (gcy-1, gcy-3, and dak-1), gluconeogenesis (fbp-1 and pck-1), and catalase (ctt-1) was activated in the wild-type strain, but not in the os-2 mutant.

An Os-1 family histidine kinase from a filamentous fungus confers fungicide-sensitivity to yeast.

Three groups of fungicides (phenylpyrroles, dicarboximides, aromatic hydrocarbons) are effective against filamentous fungi. The target of these fungicides is the osmotic stress signal transduction pathway, which is dependent on the Os-1 family of two-component histidine kinases. These fungicides usually have no fungicidal effect on the yeast Saccharomyces cerevisiae.

A two-component histidine kinase of the rice blast fungus is involved in osmotic stress response and fungicide action.

We isolated and characterized a histidine kinase gene (HIK1) from the rice blast fungus, Pyricularia oryzae (Magnaporthe grisea). The deduced amino acid sequence of HIK1 showed highest similarity (85.7%) to a hybrid-type histidine kinase, Os-1/Nik-1 of Neurospora crassa.

Putative homologs of SSK22 MAPKK kinase and PBS2 MAPK kinase of Saccharomyces cerevisiae encoded by os-4 and os-5 genes for osmotic sensitivity and fungicide resistance in Neurospora crassa.

We cloned and characterized Neurospora NcSSK22 and NcPBS2 genes, similar to yeast SSK22 mitogen-activated protein (MAP) kinase kinase kinase and the PBS2 MAP kinase kinase genes, respectively. Disruptants of the NcSSK22 gene were sensitive to osmotic stress and resistant to iprodione and fludioxonil. Their phenotypes were similar to those of osmotic-sensitive (os) mutants os-1, os-2, os-4, and os-5.

Effects of iprodione and fludioxonil on glycerol synthesis and hyphal development in Candida albicans.

We investigated the effects of iprodione and fludioxonil on the pathogenic yeast Candida albicans. Growth of the wild-type IFO1385 strain of C. albicans was inhibited by both fungicides, while Saccharomyces cerevisiae was basically unaffected by them even at a concentration of 25 microg/ml.