Collaborative Research: Integration of Glandular Trichome Metabolism and Development by a Flavonoid Pathway Signal

毛状体是存在于大多数植物中的特化表皮细胞，其优化提供保护免受环境侵害的化合物的产生。由于许多腺体衍生的物质可用于工业和医药目的，因此对这些表皮“生物工厂”的广泛兴趣得到了加强。虽然已取得重大进展，在编目的代谢“零件清单”的腺毛，关于代谢的调节和发展的基本问题，毛状体结构仍有待回答。在保持与比喻的毛状体腺体作为一个生物化学工厂，这个项目旨在解决两个主要问题有关的运作原则，这一高度进化的结构：如何在工厂内的各种装配线（代谢途径）协调，以及如何在组装产品（生物活性化合物）的需求变化影响的方式，工厂的建设？这项研究有可能通过推进看似不同的代谢途径之间的交叉调节概念，并为充分表征的酶定义新的作用，来改变目前对代谢的看法。腺毛产生多种生物活性化合物，保护气生植物组织免受生物和非生物胁迫。毛状体腺体的代谢活性通常由萜类化合物和类黄酮的产生主导，萜类化合物和类黄酮包括自然界中最多样化和经济上最重要的两类化合物。阐明这些和其他次级代谢产物的生物合成途径的进展远远超过了理解发育细胞类型和结构的努力，这些细胞类型和结构通常是防御化学品生物功能的关键。该研究项目建立在最近的研究基础上，这些研究表明，番茄腺毛中的萜类化合物和类黄酮生物合成与腺体发育相关，有趣的是，它们受到类黄酮生物合成酶查尔酮异构酶（CHI）的作用的协调影响。该项目的主要目标是将联合收割机实验和数学建模方法相结合，以实现对毛状体代谢和发育过程如何整合的系统级理解。实验方法基于使用纯化的毛状腺（单细胞类型）进行转录组学，蛋白质组学和代谢组学分析，以及强大的遗传工具来操纵影响腺体发育和代谢的功能过程。这项研究还可能揭示一种经过充分研究的代谢酶（CHI）的新作用，并拓宽目前关于小分子如何控制代谢的观点。该项目为来自不同背景的学员提供多学科培训机会，包括本科生参与植物基因组学REU夏季研究计划。该项目将通过与密歇根州立大学园艺园和当地产业的合作伙伴关系，增加不同阶层公众对科学的了解。项目科学家将与4-H儿童花园、当地小学以及薄荷和其他芳香植物的商业种植者合作，为儿童提供实践学习经验，说明毛状体衍生化合物在植物生物学中的重要性。

Trichomes are specialized epidermal cells present in most plants that optimize the production of compounds that provide protection against environmental insults. Broad interest in these epidermal "biofactories" is heightened by the fact that many gland-derived substances are useful for industrial and medicinal purposes. Although significant progress has been made in cataloging the metabolic "parts list" of glandular trichomes, fundamental questions concerning the regulation of metabolism within, and development of, the trichome structure remain to be answered. In keeping with the analogy of the trichome gland as a biochemical factory, this project seeks to address two major questions concerning the operating principles of this highly evolved structure: how are various assembly lines (metabolic pathways) within the factory coordinated, and how do changes in the demand for the assembled products (bioactive compounds) influence the way in which the factory is constructed? The research has potential to transform current views of metabolism by advancing the concept of cross regulation between seemingly disparate metabolic pathways, and defining new roles for well characterized enzymes. Glandular trichomes produce a wide variety of bioactive compounds that protect aerial plant tissues from biotic and abiotic stress. The metabolic activity of trichome glands is often dominated by the production of terpenoids and flavonoids, which comprise two of the most diverse and economically important classes of compounds in nature. Progress in elucidating biosynthetic pathways for these and other secondary metabolites has far outpaced efforts to understand the developmental cell types and structures that are often key to the biological function of defense chemicals. This research project builds on recent studies showing that terpenoid and flavonoid biosynthesis in glandular trichomes of tomato is coupled to gland development and, intriguingly, is coordinately impacted by the action of the flavonoid biosynthesis enzyme chalcone isomerase (CHI). The broad objective of the project is to combine experimental and mathematical modeling approaches to achieve a systems-level understanding of how trichome metabolic and developmental processes are integrated. The experimental approaches are grounded in the use of purified trichome glands (a single cell type) for transcriptomic, proteomic, and metabolomic analyses, as well as powerful genetic tools to manipulate functional processes affecting gland development and metabolism. The research may also reveal new roles for a well-studied metabolic enzyme (CHI) and broaden current views of how small molecules control metabolism. The project provides multi-disciplinary training opportunities for trainees from diverse backgrounds, including participation of undergraduate students in the Plant Genomics REU Summer Research Program. The project will increase access by diverse segments of the public to science through partnerships with the MSU Horticulture Gardens and local industry. Project scientists will partner with the 4-H Children's Garden, local elementary schools, and commercial growers of mint and other aromatic plants to provide children with hands-on learning experiences that illustrate the importance of trichome-derived compounds in plant biology.