RNAi-Mediated Gene Silencing of Trcot1 Induces a Hyperbranching Phenotype in Trichoderma reesei.
RNAi-Mediated Gene Silencing of Trcot1 Induces a Hyperbranching Phenotype in Trichoderma reesei.
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RNAi 介导的 Trocot1 基因沉默诱导里氏木霉的超分支表型
DOI：
10.4014/jmb.1909.09050
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发表时间：
2020-02-28
影响因子：
2.8
通讯作者：
Su, Xiaoyun
中科院分区：
文献类型：
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作者：
Gao, Fei;Li, Mengzhu;Liu, Weiquan;Bai, Yingguo;Tao, Tu;Wang, Yuan;Zhang, Jie;Luo, Huiying;Yao, Bin;Huang, Huoqing;Su, Xiaoyun
里氏木霉是用于生产纤维素酶的主要丝状真菌，提高其产生更高效价的纤维素酶的能力受到了极大的关注。在影响里氏木霉产纤维素酶的诸多因素中，菌丝体的表型很重要，但研究较少。在此，在里氏脉孢霉中发现了一个与粗毛脉孢菌COT1蛋白同源的蛋白，命名为TrCOT1，氨基酸序列同源性为83.3%。通过RNAi介导的基因沉默来破坏T.reesei中Trcot1的功能，导致马铃薯葡萄糖琼脂上的孢子形成延迟，以及以葡萄糖、木聚糖、乳糖、木糖或甘油为唯一碳源的最小培养皿上的矮化菌落。代表突变株Sus2/trcot1i在MM葡萄糖液体培养中菌丝积累减少，菌丝生长单位长度由亲本菌株的239.8μm/TIP降至73.0μm/TIP，表现出高度的分枝现象。在分批培养的24-72h内，超分枝表型导致纤维素酶的分泌略有增加，但显著增加。而单位菌丝体生物量的纤维素酶产量在24~96h的提高幅度更大。
Trichoderma reesei is the major filamentous fungus used to produce cellulase and there is huge interest in promoting its ability to produce higher titers of cellulase. Among the many factors affecting cellulase production in T. reesei, the mycelial phenotype is important but seldom studied. Herein, a close homolog of the Neurospora crassa COT1 kinase was discovered in T. reesei and designated TrCOT1, which is of 83.3% amino acid sequence identity. Functional disruption of Trcot1 in T. reesei by RNAi-mediated gene silencing resulted in retarded sporulation on potato dextrose agar and dwarfed colonies on minimal medium agar plates containing glucose, xylan, lactose, xylose, or glycerol as the sole carbon source. The representative mutant strain, SUS2/Trcot1i, also displayed reduced mycelia accumulation but hyperbranching in the MM glucose liquid medium, with hyphal growth unit length values decreased to 73.0 μm/tip compared to 239.8 μm/tip for the parent strain SUS2. The hyperbranching phenotype led to slightly but significantly increased cellulase secretion from 24 to 72 h in a batch culture. However, the cellulase production per unit of mycelial biomass was much more profoundly improved from 24 to 96 h.