State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou, Zhejiang 311300, China.
College of Agriculture and Forestry, Longdong University, Qingyang 745000, China.
Food Chem. 2022 Apr 16;374:131558. doi: 10.1016/j.foodchem.2021.131558. Epub 2021 Nov 8.
The kernel of Torreya grandis (T. grandis) is a rare nut with a variety of bioactive compounds. Flavonoids are a very important class of bioactive compounds with high antioxidant activity in T. grandis kernels. However, the flavonoid compositions which mainly contribute to antioxidant capacity and the molecular basis of flavonoid biosynthesis in T. grandis remain unclear. Here, transcriptome sequencing and metabolomics analysis for kernels were performed. In total, 124 flavonoids were identified. Among them, 9 flavonoids were highly correlated with antioxidant activity. Furthermore, unigenes encoding CHS, DFR and ANS showed significant correlation with the 9 flavonoids. Transient overexpression of TgDFR1 in tobacco leaves resulted in increased antioxidant activity. Moreover, several transcription factors from MYB, bHLH and bZIP families were identified by co-expression assay, suggesting that they may regulate flavonoid biosynthesis. Our findings provide a molecular basis and new insights into the flavonoid biosynthesis in T. grandis kernels.
香榧（Torreya grandis）的内核是一种含有多种生物活性化合物的稀有坚果。类黄酮是生物活性化合物的一个非常重要的类别，具有较高的抗氧化活性。然而，香榧内核中主要具有抗氧化能力的类黄酮成分以及类黄酮生物合成的分子基础仍不清楚。本研究对香榧内核进行了转录组测序和代谢组学分析。共鉴定出 124 种类黄酮，其中 9 种类黄酮与抗氧化活性高度相关。此外，编码 CHS、DFR 和 ANS 的基因与这 9 种类黄酮表现出显著的相关性。瞬时过表达烟草叶片中的 TgDFR1 可提高抗氧化活性。此外，通过共表达分析鉴定了来自 MYB、bHLH 和 bZIP 家族的几个转录因子，表明它们可能参与了类黄酮的生物合成调控。本研究结果为香榧内核中的类黄酮生物合成提供了分子基础和新的见解。
