Control of Natural Product Production in Aromatic Herbs

烹饪和其他芳香草药为提高食品的吸引力做出了重大贡献，并在我们的社会中扮演着越来越重要的角色，作为草药疗法和补充剂行业的组成部分。然而，几乎所有生物活性次生化合物或天然产物的生物合成仍然知之甚少。兰科植物家族（如甜罗勒和薄荷）包括许多富含这种天然产物的物种。植物产生的天然产物被认为与抵御食草动物和病原体有关，而Lamiaceae物种在叶子表面进化出了复杂的结构，称为盾状腺，这些化学物质在那里合成和储存。罗勒是一种特别值得注意的草药，因为它合成了相对大量的萜类和苯丙类化合物，这两大类化合物包括许多植物防御和重要的药用天然产物，包括紫杉醇（紫杉醇）和足臼毒素（衍生成Etoposide和Teniposide），用于治疗癌症。除了一些集中的努力来描绘特定化合物的途径，如紫杉醇和鬼臼毒素，对产生这两种生物合成途径所产生的多种化合物的生化反应知之甚少。对控制或调节这些途径的基因和酶的了解就更少了。本研究项目旨在确定罗勒盾状腺中次生化合物的产生方式，并开始确定和定义控制其产生的机制。具体而言，本研究将：1)使用代谢谱来表征选定罗勒品系盆底腺体中苯丙素途径中已知代谢物和潜在中间体的水平；2)利用功能基因组学方法确定特定酶和其他调节因子在控制罗勒盆状腺体中苯丙素途径的通量中所起的作用。这些研究成果和开发的工具将为其他植物次生代谢途径的研究奠定基础。除了了解植物如何产生天然产物的内在科学价值外，这些知识对于合理设计育种策略以生产具有目标天然产物概况的植物至关重要。这些知识也将有助于应用基因工程来改进和开发新的芳香植物，这些植物可以作为制药和其他工业的原料。

Culinary and other aromatic herbs make a significant contribution to improving the appeal of foodstuff and play increasingly important roles in our society as components of the herbal remedies and supplements industry. However, the biosynthesis of almost all bioactive secondary compounds or natural products is still poorly understood. The plant family Lamiaceae (e.g., sweet basil and mint) includes many species that are rich in such natural products. Natural product production by the plant is believed to be associated with defense against herbivores and pathogens, and Lamiaceae species have evolved elaborate structures on the surface of their leaves, known as peltate glands, where these chemicals are synthesized and stored. Basil is a particularly noteworthy herb because it synthesizes relatively high amounts of both terpenoids and phenylpropanoids, two large classes of compounds that include many plant defense and medicinally important natural products, including paclitaxel (Taxol) and podophyllotoxin (derivatized to form Etoposide and Teniposide) that are used to treat cancer. Aside from some focused efforts to delineate the pathways to specific compounds, such as paclitaxel and podophyllotoxin, very little is known about the biochemical reactions that produce the great diversity of compounds that result from these two biosynthetic pathways. Even less is known about the genes and enzymes that control or regulate these pathways. This research project aims to identify how secondary compounds are produced in basil peltate glands and to begin to identify and define the mechanisms that control their production. Specifically, this research will: 1) use metabolic profiling to characterize levels of known metabolites and potential intermediates in the phenylpropanoid pathway in peltate glands of select basil lines; and 2) use a functional genomics approach to determine what roles specific enzymes and other regulatory factors play in controlling the flux into and through the phenylpropanoid pathway in basil peltate glands.The research results and developed tools will form a foundation that should facilitate research of other plant secondary metabolic pathways. In addition to the intrinsic scientific value of understanding how plants produce natural products, such knowledge is essential for rational design of breeding strategies to produce plants with targeted natural product profiles. This knowledge will also help in the application of genetic engineering to improve and develop new aromatic plants, which could then serve as feed stocks for the pharmaceutical and other industries.