Evolution of Specialized Metabolite Biosynthetic Pathways in the Lamiaceae: Sources of Chemical Diversity for Molecules Essential for Human Use and Plant Defense

Co-PI：娜塔莉亚杜达瑞娃（普渡大学）、莎拉奥康纳（英国约翰英纳斯中心）、道格拉斯索迪斯（佛罗里达大学）、帕梅拉索迪斯（佛罗里达大学）唇形科（Lamiaceae）或薄荷科（mint family）是第六大开花植物家族，是世界各地人们所喜爱的许多熟悉的薄荷和烹饪风味的来源。薄荷家族的许多成员产生所谓的次级代谢产物，这是植物化学的副产品，在草药茶中赋予薄荷或留兰香的熟悉味道，或者来自牛至，罗勒，熏衣草和其他草药的美味烹饪调味品。人类对这些植物化合物的欣赏和消费支持了不断增长的农学产业，2011年仅薄荷和留兰香油的市场价值就超过2亿美元（美国农业部）;然而，这些化合物的基本化学如何以及为什么在家族中进化尚不清楚。该项目通过基因组测序和识别每个物种中产生的所有相关因子来研究合成风味化合物所需的化学途径。通过比较家庭成员之间产生的大型数据集，该项目将阐明这些化学过程如何在植物中进化。该项目的跨学科性质需要生物化学、基因组学、遗传学和进化生物学方面的专家参与。反过来，高中生，本科生和研究生通过学习与经济价值产品直接相关的尖端基因组学研究在科学前沿进行培训。通过与密歇根州立大学4 H儿童花园和佛罗里达自然历史博物馆的合作，该项目提供了信息展示和图尔斯，使公众可以成为公民科学家，因为他们了解熟悉和备受赞赏的薄荷家族的进化和潜在的“风味”化学。唇形科是被子植物的一个大科，具有高度的化学多样性。唇形科的主要亚科，唇形科和荆芥亚科，可以很容易地区分形态，也显示出定性和定量的差异，在两个关键的专门化合物，环烯醚萜和挥发性单萜类化合物的合成。这些化合物在植物繁殖、防御和信号传导中起着至关重要的作用，也是人类消费的薄荷和其他草药风味的来源。本研究整合基因组、代谢物、系统发育及功能性资料，探讨唇形科单萜及环烯醚萜类化合物生物合成途径的演化。在第一阶段，将生成和分析50个物种的遗传多样性小组的转录组和代谢组，以确定一组14个物种的强大集中研究。在第二阶段，将对选定的集合进行全基因组测序、表达和代谢物水平，从而提供资源以（1）鉴定参与单萜和环烯醚萜生物合成的特定基因，（2）阐明导致唇形科中代表的现存化学多样性的关键进化事件和机制，以及（3）功能性地测试关于生物合成途径基因的变异如何有助于化学多样性的假设。该项目的所有资源，包括基因组、转录组序列和代谢物信息，将通过出版物、NCBI序列档案、Dryad数字知识库公开提供，并张贴在密歇根州立大学托管的项目网站上。

Co-PIs: Natalia Dudareva (Purdue University), Sarah O'Connor (John Innes Centre, UK), Douglas Soltis (University of Florida), Pamela Soltis (University of Florida)The sixth largest flowering plant family, the Lamiaceae or mint family, is the source of many familiar mint and culinary flavors enjoyed by people worldwide. Many members of the mint family produce so-called secondary metabolites, which are by-products of plant chemistry that impart the familiar flavors of peppermint or spearmint in herbal teas or savory culinary seasoning from oregano, basil, lavender and other herbs. Human appreciation and consumption of these botanical compounds supports a growing agronomic industry, with the market for peppermint and spearmint oil alone worth over $200 million in 2011 (USDA); and yet how and why the underlying chemistry of these compounds evolved in the family is unknown. This project studies the chemical pathways required to synthesize flavor compounds using genome sequencing and by identifying all the relevant factors produced in each species. By comparing the resulting large datasets across family members, the project will clarify how such chemical processes evolved in plants. The interdisciplinary nature of the project requires the participation of experts in biochemistry, genomics, genetics and evolutionary biology. In turn, high school, undergraduate, and graduate students are trained at the frontiers of science by learning cutting edge genomics research that links directly to products of economic value. Through collaboration with the Michigan State University 4H Children's Garden and the Florida Museum of Natural History, the project offers informative displays and tours so the public can become citizen scientists as they learn about the evolution and underlying "flavor" chemistry of the familiar and much appreciated mint family. The Lamiaceae represents a large family of angiosperms with a high degree of chemical diversity. The major subfamilies within the Lamiaceae, the Lamioideae and Nepetoideae, can be readily distinguished morphologically and also show qualitative and quantitative differences in the synthesis of two key specialized compounds, iridoids and volatile monoterpenoids. These compounds play an essential role in plant reproduction, defense, and signaling and are also the source of mint and other herbal flavors for human consumption. This project integrates genomic, metabolite, phylogenetic, and functional datasets to investigate the evolution of the monoterpene and iridoid biosynthetic pathways in the Lamiaceae. In the first phase, the transcriptomes and metabolomes of a phylogenetically diverse panel of 50 species will be generated and analyzed to identify a robust set of 14 species for focused study. In the second phase, full genome sequencing, expression, and metabolite levels will be conducted on the selected set, thus providing resources to (1) identify specific genes involved in monoterpene and iridoid biosynthesis, (2) elucidate key evolutionary events and mechanisms that led to the extant chemical diversity represented in the Lamiaceae, and (3) functionally test hypotheses about how variation in biosynthetic pathway genes contribute to chemical diversity. All resources from the project, including genome, transcriptome sequences and metabolite information will be publicly available through publications, the NCBI sequence archives, the Dryad Digital Repository and posted on a project website hosted at Michigan State University.