National Engineering Research Centre of Edible Fungi, Key Laboratory of Applied Mycological Resources and Utilisation, Ministry of Agriculture, Institute of Edible Fungi, Shanghai Academy of Agriculture Sciences, Shanghai, China.
Key Laboratory of Biophysics of MOE, College of Life Science and Technology, Huazhong University of Science and Technology, Hubei, China.
Appl Environ Microbiol. 2021 Jun 11;87(13):e0053321. doi: 10.1128/AEM.00533-21.
To systemically understand the biosynthetic pathways of bioactive substances, including triterpenoids and polysaccharides, in Ganoderma lucidum, the correlation between substrate degradation and carbohydrate and triterpenoid metabolism during growth was analyzed by combining changes in metabolite content and changes in related enzyme expression in over 5 growth phases. Changes in low-polarity triterpenoid content were correlated with changes in glucose and mannitol contents in fruiting bodies. Additionally, changes in medium-polarity triterpenoid content were correlated with changes in the lignocellulose content of the substrate and with the glucose, trehalose, and mannitol contents of fruiting bodies. Weighted gene coexpression network analysis (WGCNA) indicated that changes in trehalose and polyol contents were related to carbohydrate catabolism and polysaccharide synthesis. Changes in triterpenoid content were related to expression of the carbohydrate catabolic enzymes laccase, cellulase, hemicellulase, and polysaccharide synthase and to the expression of several cytochrome P450 monooxygenases (CYPs). It was concluded that the products of cellulose and hemicellulose degradation participate in polyol, trehalose, and polysaccharide synthesis during initial fruiting body formation. These carbohydrates accumulate in the early phase of fruiting body formation and are utilized when the fruiting bodies mature and a large number of spores are ejected. An increase in carbohydrate metabolism provides additional precursors for the synthesis of triterpenoids. Most studies of have focused on its medicinal function and on the mechanism of its activity, whereas the physiological metabolism and synthesis of bioactive substances during the growth of this species have been less studied. Therefore, theoretical guidance for cultivation methods to increase the production of bioactive compounds remains lacking. This study integrated changes in the lignocellulose, carbohydrate, and triterpenoid contents of with enzyme expression from transcriptomics data using WGCNA. The findings helped us better understand the connections between substrate utilization and the synthesis of polysaccharides and triterpenoids during the cultivation cycle of . The results of WGCNA suggest that the synthesis of triterpenoids can be enhanced not only through regulating the expression of enzymes in the triterpenoid pathway, but also through regulating carbohydrate metabolism and substrate degradation. This study provides a potential approach and identifies enzymes that can be targeted to regulate lignocellulose degradation and accelerate the accumulation of bioactive substances by regulating substrate degradation in .
为了系统地了解灵芝中生物活性物质(包括三萜类化合物和多糖)的生物合成途径,本研究通过结合超过 5 个生长阶段的代谢物含量变化和相关酶表达变化,分析了在生长过程中基质降解与碳水化合物和三萜类代谢之间的相关性。低极性三萜类化合物含量的变化与子实体中葡萄糖和甘露醇含量的变化相关。此外,中极性三萜类化合物含量的变化与基质木质纤维素含量的变化以及子实体中葡萄糖、海藻糖和甘露醇含量的变化相关。加权基因共表达网络分析(WGCNA)表明,海藻糖和多元醇含量的变化与碳水化合物分解代谢和多糖合成有关。三萜类化合物含量的变化与碳水化合物分解代谢酶漆酶、纤维素酶、半纤维素酶和多糖合酶的表达以及几种细胞色素 P450 单加氧酶(CYPs)的表达相关。综上所述,纤维素和半纤维素降解产物参与了多糖、海藻糖和三萜类化合物在初始子实体形成过程中的合成。这些碳水化合物在子实体形成的早期阶段积累,并在子实体成熟和大量孢子弹出时被利用。碳水化合物代谢的增加为三萜类化合物的合成提供了更多的前体。 对灵芝的研究大多集中在其药用功能及其活性机制上,而对该物种生长过程中生物活性物质的生理代谢和合成研究较少。因此,在增加生物活性化合物产量的栽培方法方面,理论指导仍然缺乏。本研究通过 WGCNA 整合了灵芝木质纤维素、碳水化合物和三萜类含量的变化与转录组学数据中的酶表达,帮助我们更好地理解了在灵芝培养周期中基质利用与多糖和三萜类合成之间的联系。WGCNA 的结果表明,不仅可以通过调节三萜类途径中的酶表达来增强三萜类化合物的合成,还可以通过调节碳水化合物代谢和基质降解来增强三萜类化合物的合成。本研究为通过调节木质纤维素降解和基质降解来调节生物活性物质的积累提供了一种潜在的方法,并鉴定了可以通过调节基质降解来调节酶的表达以加速灵芝中生物活性物质积累的酶。