Hyphal morphology is considered to have a close relationship with the production level of secreted proteins by filamentous fungi. In this study, the gul1 gene, which encodes a putative mRNA-binding protein, was disrupted in cellulase-producing fungus Trichoderma reesei. The hyphae of Δgul1 strain produced more lateral branches than the parent strain. Under the condition for cellulase production, disruption of gul1 resulted in smaller mycelial clumps and significantly lower viscosity of fermentation broth. In addition, cellulase production was improved by 22% relative to the parent strain. Transcriptome analysis revealed that a set of genes encoding cell wall remodeling enzymes as well as hydrophobins were differentially expressed in the Δgul1 strain. The results suggest that the regulatory role of gul1 in cell morphogenesis is likely conserved in filamentous fungi. To our knowledge, this is the first report on the engineering of gul1 in an industrially important fungus.

中文翻译：

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里氏木霉 gul1 基因的破坏会刺激菌丝分枝并降低纤维素酶生产中的肉汤粘度

菌丝形态被认为与丝状真菌分泌蛋白的产生水平密切相关。在这项研究中，编码假定的 mRNA 结合蛋白的 gul1 基因在产生纤维素酶的真菌里氏木霉中被破坏。Δgul1菌株的菌丝比亲本菌株产生更多的侧枝。在纤维素酶生产条件下，gul1 的破坏导致更小的菌丝团块和发酵液的粘度显着降低。此外，相对于亲本菌株，纤维素酶产量提高了 22%。转录组分析显示，一组编码细胞壁重塑酶和疏水蛋白的基因在 Δgul1 菌株中差异表达。结果表明，gul1 在细胞形态发生中的调节作用可能在丝状真菌中是保守的。据我们所知，这是关于工业重要真菌中 gul1 工程的第一份报告。