Artemisinin Biosynthesis: Control of Transcription

描述（由申请人提供）：青蒿素（AN）及其衍生物被证明是有效的抗疟疾治疗药物，也被证明具有广谱抗菌剂和抗癌治疗药物的有效活性。AN是一种复杂的化合物，最好由植物黄花蒿生产。然而，关于AN的生物合成是如何被调节的，我们知之甚少，尽管对其生产有以下了解：当植物从营养生长转向开花时，或者在葡萄糖而不是蔗糖上生长时，会产生更多的AN或其前体青蒿酸（AA）（我们最近的数据）。由于这些条件强烈影响AN的产生，我们建议利用它们来研究AN生物合成基因的转录调控。我们的假设是：1；青蒿素生物合成在该途径的多个步骤中受到调节，包括早期（FDP前）和晚期（FDP后）。2. 发育阶段和碳源调控了该途径中多个基因的转录。3. 青蒿素和甾醇生产的协调控制发生在转录水平上。技术目标：我们工作的长期目标是对黄花蒿中萜烯生产的调节控制有一个基本的了解，以便萜类生物合成的代谢操纵最终不仅可以用于青蒿素，还可以用于其他重要的治疗植物产生的萜类药物。这项工作有三个目标要在两年半的时间内完成：1。比较黄花苜蓿幼苗从营养生长转向开花条件时，萜类生物合成基因二磷酸法尼酯（FDP）前和FDP后导致AN的相对表达量与AA、DHAA和AN产量的关系。2. 比较在葡萄糖、果糖和蔗糖环境下生长的黄花蒿幼苗中，萜类生物合成基因二磷酸法尼酯（FDP）前和FDP后导致AN的相对表达与AA、DHAA和AN产量的关系。3. 在这些研究中包括对SQS表达的分析，以确定表达的坐标控制。不幸的是，像AN这样的植物产品在植物中产生的重要性仍然知之甚少，而在低成本的田间种植植物中高产量的萜类化合物仍然具有挑战性。这一信息很重要，因为几乎没有全面的努力来充分了解不仅是这种非常重要的治疗倍半萜的调节，而且还有其他可能具有非常有益的药用价值的植物来源的萜。治疗疟疾最有效的药物青蒿素是由“甜安妮”这种植物生产的，但其含量太低，无法提供足够的剂量，以每年治疗世界各地发生的数百万例病例。这项拟议中的研究是帮助我们了解如何控制青蒿素的生物合成，从而最终在低成本的田间种植植物中增加这种药物以及其他化学成分相似的药物的产量的第一步。

DESCRIPTION (provided by applicant): Artemisinin (AN), and its derivatives are proven effective antimalarial therapeutics that also been shown to have effective activity as broad spectrum antimicrobials, and anticancer therapeutics. AN is a complex compound and still best produced by the plant Artemisia annua. Little is known, however, about how AN biosynthesis is regulated, although the following is known about its production: more AN or its precursor, artemisinic acid (AA), is made when plants shift from vegetative growth to flowering, or grown on glucose instead of sucrose (our recent data). Since these conditions strongly affect AN production, we propose to use them to study the transcriptional regulation of AN biosynthetic genes. OUR HYPOTHESES: 1. Artemisinin biosynthesis is regulated at multiple steps in the pathway, both early (pre- FDP) and late (post-FDP). 2. Developmental stage and carbon source regulate the transcription of several genes in this pathway. 3. Coordinate control of artemisinin and sterol production occurs at the level of transcription. TECHNICAL OBJECTIVES: The long-term goal of our work is to develop a fundamental understanding of the regulatory control of terpene production in Artemisia annua so that metabolic manipulation of terpenoid biosynthesis can eventually be developed not only for artemisinin but other therapeutically important plant produced terpenoid drugs. This work has 3 objectives to be accomplished over 2.5 years: 1. To compare the relative expression of the terpenoid biosynthetic genes pre farnesyl diphosphate (FDP), and post FDP leading to AN with levels of both AA, DHAA, and AN production in A. annua seedlings as they are shifted from vegetative growth to conditions that induce flowering. 2. To compare the relative expression of the terpenoid biosynthetic genes pre farnesyl diphosphate (FDP), and post FDP leading to AN with levels of both AA, DHAA, and AN production in A. annua seedlings grown in glucose, fructose, and sucrose. 3. Include analysis of SQS expression in these studies to determine coordinate control of expression. Unfortunately little is still known about how important plant products like AN are produced in the plant and high production of terpenoids in low cost field-grown plants still remains challenging. This information is important because there has been little comprehensive effort to fully understand the regulation of not only this very important therapeutic sesquiterpene, but also other plant-derived terpenes that could have potentially very beneficial medicinal applications. The most potent therapeutic available for curing malaria, artemisinin, is produced in the plant, "Sweet Annie", but at levels too low to be able to provide adequate doses to annually treat the millions of cases that occur worldwide. The proposed study is a first step in helping us understand how to control artemisinin's biosynthesis to ultimately increase the production of this drug, and others that are chemically similar, in low cost field-grown plants.