Ren Xujiao, Wang Juying, Huang Lingling, Cheng Kaisen, Zhang Meifang, Yang Hailong
School of Life & Environmental Sciences, Wenzhou University, Wenzhou, China.
Int J Med Mushrooms. 2020;22(2):133-144. doi: 10.1615/IntJMedMushrooms.2020033683.
Total phenolics, flavonoids, and polysaccharides, and individual ganoderic acid (GA) contents, antioxidant capacity, and transcription levels of key enzyme genes involved in GA biosynthesis in pileus and stipes of Ganoderma lucidum fruiting body at different growth stages were investigated in this study. Results showed that the highest total phenolics and total flavonoids contents were determined in stipes at spore maturity stage, resulting in high antioxidant activity, while the highest total polysaccharide content was found in pileus at the same stage. The pileus contained more GA than the stipes, and higher contents of ganoderic acid A and D were found at fruiting body mature stage while that of ganoderic acid B, C2, and G were found at bud elongation stage. Results from quantitative real-time PCR indicated that higher gene transcription levels of hydroxyl methylglutaryl-CoA reductase (hmgr), farnesyl pyrophosphate synthase (fps), squalene synthase (sqs), and oxidosqualene cyclase (osc) were found in pileus at bud elongation stage. Our findings will be helpful for understanding the biosynthesis of bioactive components and determining the harvest time for the desired G. lucidum fruiting bodies.
本研究对不同生长阶段的灵芝子实体菌盖和菌柄中总酚、黄酮、多糖以及各灵芝酸（GA）含量、抗氧化能力和GA生物合成相关关键酶基因的转录水平进行了研究。结果表明，孢子成熟期菌柄中的总酚和总黄酮含量最高，抗氧化活性也高，而同一阶段菌盖中的总多糖含量最高。菌盖中的GA含量高于菌柄，在子实体成熟期灵芝酸A和D的含量较高，而在芽伸长阶段灵芝酸B、C2和G的含量较高。实时定量PCR结果表明，芽伸长阶段菌盖中羟甲基戊二酰辅酶A还原酶（hmgr）、法尼基焦磷酸合酶（fps）、鲨烯合酶（sqs）和氧化鲨烯环化酶（osc）的基因转录水平较高。我们的研究结果将有助于理解生物活性成分的生物合成，并确定所需灵芝子实体的收获时间。
