Key Laboratory of Beijing for Identification and Safety Evaluation of Chinese Medicine, Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Artemisinin Research Center, China Academy of Chinese Medical Sciences, Beijing 100700, China.
J Agric Food Chem. 2021 Feb 10;69(5):1714-1726. doi: 10.1021/acs.jafc.0c06989. Epub 2021 Jan 29.
Ginseng contains a variety of flavonol glycosides that possess diverse biological activities; however, scant information of flavonoid glycosylation was reported in ginseng. We found that panasenoside and kaempferol 3--glucoside were commonly accumulated along with cultivation years in leaves. In order to explore the procedure of flavonol glycosylation in ginseng, 50 UDP-glycosyltransferases (UGTs) were screened out using differentiated data-independent acquisition (DIA) proteomics and phylogenetic analysis. UGT92A10 and UGT94Q4 were found contributing to the formation of kaempferol 3--glucoside. UGT73A18, UGT74T4, and UGT75W1 could catalyze galactosylation of kaempferol 3--glucoside. Ser278, Trp335, Gln338, and Val339 were found forming hydrogen bonds with UDP-galactose in UGT75W1 by docking. MeJA induced transcripts of UGT73A18 and UGT74T4 by over fourfold, consistent with the decrease of kaempferol 3--glucoside, which indicated that these genes may be related to resisting adversity stress in ginseng. These results highlight the significance of integrative metabolite profiles, proteomics, and phylogenetic analysis for exploring flavonol glycosylation in ginseng.
人参含有多种具有多种生物活性的黄酮醇糖苷，但关于人参中类黄酮糖基化的信息却很少。我们发现，随着种植年限的增加，人参叶中潘那塞索苷和山柰酚 3-O-葡萄糖苷会不断积累。为了探究人参中类黄酮糖基化的过程，我们利用差异非依赖性采集（DIA）蛋白质组学和系统发育分析筛选出了 50 种 UDP-糖基转移酶（UGTs）。研究发现，UGT92A10 和 UGT94Q4 参与了山柰酚 3-O-葡萄糖苷的形成。UGT73A18、UGT74T4 和 UGT75W1 可以催化山柰酚 3-O-葡萄糖苷的半乳糖基化。通过对接发现，UGT75W1 中的 Ser278、Trp335、Gln338 和 Val339 与 UDP-半乳糖形成氢键。茉莉酸甲酯（MeJA）诱导 UGT73A18 和 UGT74T4 的转录水平增加了四倍以上，与山柰酚 3-O-葡萄糖苷的含量下降一致，这表明这些基因可能与人参抵抗逆境胁迫有关。这些结果突出了综合代谢物图谱、蛋白质组学和系统发育分析在探索人参中类黄酮糖基化过程中的重要性。
