Effects on hyphal morphology and development by the putative copper radical oxidase glx1 in Trichoderma virens suggest a novel role as a cell wall associated enzyme
| Autor: | Maria E. Moran-Diez, Frankie K. Crutcher, Inna Krieger, Charles M. Kenerley |
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| Rok vydání: | 2019 |
| Předmět: |
Hyphal growth
Mutant Hyphae Sequence Homology Microbiology Lignin Cell wall Fungal Proteins 03 medical and health sciences chemistry.chemical_compound Cell Wall Catalytic Domain Gene Expression Regulation Fungal Genetics Amino Acid Sequence Gene Silencing 030304 developmental biology chemistry.chemical_classification Trichoderma 0303 health sciences Oxidase test biology 030306 microbiology Methylglyoxal Hydrogen Peroxide Spores Fungal biology.organism_classification Amino acid Alcohol Oxidoreductases Enzyme Phenotype chemistry Biochemistry Copper |
| Zdroj: | Fungal genetics and biology : FGB. 131 |
| ISSN: | 1096-0937 |
| Popis: | Trichoderma spp. have been characterized for their capacity to act as biological control agents against several pathogens through the activity of secondary metabolites and cell wall degrading enzymes. However, only T. reesei has been widely studied for the ability to assimilate lignocellulose substrates. Protein analysis by SDS-PAGE of culture filtrate of T. virens revealed the presence of an unknown ∼77 kDa band protein (GLX1) that showed sequence homology to glyoxal-like oxidase genes involved in lignin degradation. The analysis and biochemical characterization of the 1,119 amino acid coded protein showed the presence of five carbohydrate-binding modules (CBMs) with affinity for colloidal chitin, and a functional glyoxal oxidase catalytic domain that is involved in the production of hydrogen peroxide when methylglyoxal was used as a substrate. The silencing of the glx1 gene resulted in mutants with more than 90% expression reduction and the absence of glyoxal oxidase catalytic activity. These mutants showed delayed hyphal growth, reduced colony and conidial hydrophobicity, but showed no changes in their biocontrol ability. Most significantly, mutants exhibited a loss of growth directionality resulting in a curled phenotype that was eliminated in the presence of exogenous H2O2. Here we present evidence that in T. virens, glx1 is not involved in the breakdown of lignin but instead is responsible for normal hyphal growth and morphology and likely does this through free radical production within the fungal cell wall. This is the first time that a glyoxal oxidase protein has been isolated and characterized in ascomycete fungi. |
| Databáze: | OpenAIRE |
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