College of Life Science and Technology, Henan Institute of Science and Technology, Xinxiang, 453003, Xinxiang, People's Republic of China.
Collaborative Innovation Center of Modern Biological Breeding of Henan Province, Xinxiang, 453003, Xinxiang, People's Republic of China.
Appl Microbiol Biotechnol. 2021 Oct;105(19):7353-7365. doi: 10.1007/s00253-021-11564-9. Epub 2021 Sep 13.
The telomerase reverse transcriptase (TERT) is the core catalytic subunit of telomerase. Its canonical function is synthesizing telomeric repeats to maintain telomere length and chromosomal stability. Accumulating evidence suggests that TERT has other important fundamental functions in addition to its catalytic telomere repeat synthesis activity. However, the non-canonical roles of TERT independent of its enzymatic activity are not clear in filamentous fungi. In the present study, we characterized the GlTert gene in Ganoderma lucidum. The non-canonical roles of GlTert were explored using GlTert-silenced strains (Terti8 and Terti25) obtained by RNA interference. Silencing GlTert delayed the fungal growth, decreased the length between hyphal branches, and induced fungal resistance to oxidative stress in G. ludicum. Further examination revealed that the intracellular ROS (reactive oxygen species) levels were increased while the enzyme activities of the antioxidant systems (superoxide dismutase, catalase, glutathione peroxidase, and ascorbate peroxidase) were decreased in GlTert-silenced strains. In addition, silencing GlTert decreased the ganoderic acid (GA) biosynthesis of G. lucidum. Taken together, our results indicate that GlTert plays a fundamental function on fungal growth, oxidative stress, and GA biosynthesis in G. lucidum, providing new insights for the canonical functions of TERT in filamentous fungi. KEY POINTS: • GlTert affected fungal growth and hyphal branching of G. lucidum. • Silencing GlTert increased the intracellular ROS levels of G. lucidum. • GlTert regulated GA biosynthesis of G. lucidum.
端粒酶逆转录酶（TERT）是端粒酶的核心催化亚基。其典型功能是合成端粒重复序列，以维持端粒长度和染色体稳定性。越来越多的证据表明，TERT 除了其催化端粒重复合成活性外，还有其他重要的基本功能。然而，在丝状真菌中，TERT 非酶活性的非典型作用尚不清楚。在本研究中，我们对灵芝中的 GlTert 基因进行了表征。通过 RNA 干扰获得的 GlTert 沉默菌株（Terti8 和 Terti25），探索了 GlTert 的非典型作用。沉默 GlTert 会延迟真菌生长、减少菌丝分支之间的长度，并诱导灵芝对氧化应激的抗性。进一步研究表明，沉默 GlTert 会增加细胞内 ROS（活性氧）水平，同时降低抗氧化系统（超氧化物歧化酶、过氧化氢酶、谷胱甘肽过氧化物酶和抗坏血酸过氧化物酶）的酶活性。此外，沉默 GlTert 会降低灵芝中的灵芝酸（GA）生物合成。总之，我们的结果表明，GlTert 在灵芝的真菌生长、氧化应激和 GA 生物合成中发挥着基本功能，为 TERT 在丝状真菌中的典型功能提供了新的见解。关键点：• GlTert 影响灵芝的真菌生长和菌丝分支。• 沉默 GlTert 增加了灵芝细胞内的 ROS 水平。• GlTert 调节灵芝的 GA 生物合成。
