Monoterpenoid Pheromone Production in Coleoptera: Characterization of Geranyl Diphosphate Synthase

鞘翅目昆虫是美国最具破坏性的害虫之一。 在北美，树皮甲虫每年造成数十亿立方英尺的针叶树立木损失。 棉铃象鼻虫Anthonomas grandis造成的年均产量损失和防治成本超过3亿美元。 树皮甲虫和棉铃象甲在动物中是独特的，因为它们都产生交配和繁殖所需的单萜，C10信息素成分。 本项目的长期目标是开发基于昆虫信息素系统的新的有效的害虫管理策略。 为了充分利用信息素介导的树皮甲虫和棉铃象甲的行为，从管理的角度来看，这些信号的起源，表达和活动的透彻理解是很重要的。 最近在Blomquist/Tittiger实验室的工作表明，雄性松刻甲虫，松细叶甲，从头合成ipsdienol，并通过保幼激素（JH）诱导3-羟基-3-甲基戊二酰辅酶A还原酶（HMG-R）和HMG-CoA合成酶（HMG-S）转录水平的生产控制。 类单萜信息素生产中的另一个关键酶是香叶基二磷酸合酶（GPPS），其控制类异戊二烯产物的链长。工作建议，以了解这种酶的活性的调节信息素的生产和克隆，序列和模型的酶。 本建议中概述的研究是重要的，因为它们对类异戊二烯生物化学和基础昆虫分子生物学的影响。 越来越清楚的是，植物单萜完全通过非甲羟戊酸途径合成，使得Ips spp.和A. grandis相对新颖的系统，用于研究基于甲羟戊酸的单萜类化合物生物合成的调节。 此外，很少有其他昆虫模型，其中异戊二烯基二磷酸脱氢酶的分子生物学进行了研究，这些都没有涉及GPPS或建模研究。 而且，这些其他模型都不具有像I的情况那样可以容易地以mg量回收的单萜类终产物。pini和A. grandis. 最后，对松小卷叶螟（Ips pini）和A. grandis信息素生物合成，特别是关键类异戊二烯酶的转录，代表了用于研究JH调节的基因表达的非发育模型系统。 这项工作的基础上，并扩大了在Blomquist/Tittiger实验室进行的昆虫信息素调节的分子生物学研究的开创性工作。

Insects in the order Coleoptera are among the most destructive pests in the United States. Bark beetles are responsible for losses of billions of cubic feet of coniferous standing timber each year in North America. The cotton boll weevil Anthonomas grandis accounts for over $300 million average annual yield loss and control costs. The bark beetles and the boll weevil are unique among animals in that both produce monoterpenes, C10 pheromone components that are required for mating and reproduction. The long term goal of this project is to develop new and effective pest management tactics based on insect pheromone systems. To fully exploit pheromone-mediated bark beetle and cotton boll weevil behavior from a management standpoint, a thorough understanding of the origin, expression and activity of these signals is important. Recent work in the Blomquist/Tittiger laboratory has demonstrated that the male pine engraver beetle, Ips pini, synthesizes ipsdienol de novo, and that production is controlled by juvenile hormone (JH) which induces 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-R) and HMG-CoA synthase (HMG-S) transcript levels. Another key enzyme in monoterpenoid pheromone production is geranyl diphosphate synthase (GPPS), which controls the chain length of the isoprenoid product. Work is proposed to gain an understanding of the regulation of the activity of this enzyme in relationship to pheromone production and to clone, sequence and model the enzyme. The studies outlined in this proposal are significant because of their impact on isoprenoid biochemistry and basic insect molecular biology. It is becoming clear that plant monoterpenes are synthesized entirely via the non-mevalonate pathway, making Ips spp. and A. grandis relatively novel systems for the study of the regulation of mevalonate-based monoterpenoid biosynthesis. Furthermore, there are few other insect models in which the molecular biology of isoprenyl diphosphate synthases have been studied, and none of these have involved GPPS or modeling studies. Also, none of these other models has a monoterpenoid end product that can be readily recovered in mg quantities as is the case with I. pini and A. grandis. Finally, Ips pini and A. grandis pheromone biosynthesis, and specifically the transcription of key isoprenoid enzymes, represents a non-developmental model system for the study of JH regulated gene expression. This work builds upon and expands the pioneering work on the molecular biological studies of insect pheromone regulation performed in the Blomquist/Tittiger laboratories.