n nnnSaponins, an important group of bioactive plant natural products,are glycosides of triterpenoid or steroidal aglycones (sapogenins).Saponins possess many biological activities, including conferringpotential health benefits for humans. However, most of the stepsspecific for the biosynthesis of triterpene saponins remainuncharacterized at the molecular level. Here, we use comprehensivegene expression clustering analysis to identify candidate genesinvolved in the elaboration, hydroxylation, and glycosylationof the triterpene skeleton in the model legume Medicago truncatula.Four candidate uridine diphosphate glycosyltransferases wereexpressed in Escherichia coli, one of which (UGT73F3) showedspecificity for multiple sapogenins and was confirmed to glucosylatehederagenin at the C28 position. Genetic loss-of-function studiesin M. truncatula confirmed the in vivo function of UGT73F3 insaponin biosynthesis. This report provides a basis for futurestudies to define genetically the roles of multiple cytochromesP450 and glycosyltransferases in triterpene saponin biosynthesisin Medicago.展开▼
机译:ABSTRACTn FONT> TH> TR> TABLE> n
n TOP n <字体颜色= 464c53>抽象 FONT> n 介绍 n 结果 n 讨论 n 方法 n 参考文献 n FONT> TH> TR> TABLE> n nnnSaponins,一种重要的具有生物活性的植物天然产物, SUP> ar三萜类或甾体苷元(皂甙元)的糖苷。 SUP>皂苷具有许多生物学活性,包括赋予人类 SUP>潜在的健康益处。但是,大多数三萜皂苷生物合成的特定步骤 SUP>在分子水平上仍未表征。在这里,我们使用全面的 SUP>基因表达聚类分析来确定候选模型 SUP>参与模型中三萜骨架的精制,羟基化和糖基化 SUP>豆科植物 Me藜 I>。 SUP>在大肠杆菌 I>中表达了四种候选尿苷二磷酸糖基转移酶,其中一种(UGT73F3)显示 SUP>对多种皂苷元的特异性,并在C28位置被证实对糖基化的 SUP>七叶皂甙元。 M中的遗传功能丧失研究 SUP>。截骨 I>证实了UGT73F3在 SUP>皂苷生物合成中的体内功能。该报告为未来的 SUP>研究从遗传上定义多种细胞色素 SUP> P450和糖基转移酶在三萜皂苷生物合成 SUP>在 Medicago < / I>。 SUP>
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