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.

木霉属。已经通过次级代谢产物和细胞壁降解酶的活性表征了它们作为针对几种病原体的生物防治剂的能力。但是，仅对里氏木霉的同化木质纤维素底物的能力进行了广泛的研究。通过SDS-PAGE蛋白质分析T. virens的蛋白质结果表明存在一个未知的〜77 kDa条带蛋白（GLX1），该蛋白与参与木质素降解的乙二醛样氧化酶基因具有序列同源性。对1,119个氨基酸编码蛋白的分析和生化特征表明，存在五个与胶体几丁质具有亲和力的碳水化合物结合模块（CBM），以及使用甲基乙二醛时涉及过氧化氢产生的功能性乙二醛氧化酶催化域。作为基材。glx1的沉默该基因导致突变体的表达降低了90％以上，并且没有乙二醛氧化酶的催化活性。这些突变体显示出延迟的菌丝生长，减少的菌落和分生孢子疏水性，但是在其生物防治能力方面没有显示任何变化。最重要的是，突变体表现出生长方向性的丧失，导致卷曲的表型，该表型在存在外源H ₂ O ₂的情况下被消除。在这里，我们提供证据表明，在T. virens中，glx1它不参与木质素的分解，但负责正常的菌丝生长和形态，很可能是通过真菌细胞壁内的自由基产生来实现的。这是首次在子囊真菌中分离并表征了乙二醛氧化酶蛋白。