Proteomics and metabolomics reveal the mechanism underlying differential antioxidant activity among the organs of two base plants of Shiliang tea (Chimonanthus salicifolius and Chimonanthus zhejiangensis).

The leaves and branches of Chimonanthus salicifolius and Chimonanthus zhejiangensis are the base ingredients of Shiliang tea. In this study, proteomics and metabolomics were performed to understand the molecular mechanisms underlying antioxidant activity (AA) in the leaves and branches of the two species. Stress and redox related proteins are differentially expressed among organs. The abundance of isoprenoid pathway-related proteins is higher in leaves while the abundance of phenylpropanoid and flavonoid pathway-related proteins is higher in branches in both species. Metabolomics revealed the flavonoid composition and demonstrated that procyanidins are more abundant in branches. Superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and AA are stronger in branches than leaves. Overall, branches might contribute to redox homeostasis through SOD/GSH-PX and flavonoids. Furthermore, the high level of AA of branches might be largely due to their increased accumulation of procyanidins.

Comparative Studies on Bioactive Compounds, Ganoderic Acid Biosynthesis, and Antioxidant Activity of Pileus and Stipes of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes) Fruiting Body at Different Growth Stages.

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.