Evolution of Secondary Herbivore Defense Metabolite Biosynthesis from Primary Metabolism in the non-model Crucifer Erysimum (wallflower)

非模型十字花科植物 Erysimum（壁花）初级代谢的次生草食动物防御代谢物生物合成的演变

• 批准号: 1811965
• 负责人: Cynthia Holland
• 金额: $ 21.6万
• 依托单位: Holland Cynthia K
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1811965&HistoricalAwards=false
• 关键词: Evolution; Secondary; Herbivore; Defense; Metabolite

This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2018. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Dr. Cynthia Holland is "Evolution of Secondary Herbivore Defense Metabolite Biosynthesis from Primary Metabolism in the non-model Crucifer Erysimum (wallflower)." The host institution for the fellowship is the Boyce Thompson Institute and the sponsoring scientists are Drs. Georg Jander and Lukas Mueller.To protect themselves against insect herbivores, plants have evolved a wide variety of chemical defenses. One class of plant defensive metabolites, known as cardiac glycosides, is found in at least twelve plant families and works by slowing the contractions and increasing the pumping force of the predator's heart. Despite the therapeutic use of these compounds in treating arrhythmias and congestive heart failure, a complete pathway for cardiac glycoside biosynthesis is not known for any plant species. This project will use the cardiac glycoside-producing wormseed wallflower (Erysimum cheiranthoides) to identify the biosynthetic pathway genes for these compounds. These results will contribute to the understanding of the evolution of defensive chemicals in other plant species, including important crops such as maize, soybean, and wheat. Training objectives include metabolomics, genetics, gene expression technologies and bioinformatics. Broader impacts include introducing underrepresented students to genomics and chemical ecology research via mentoring through an NSF-funded REU program, outreach to high school students at an urban high school in Yonkers (NY) and the development of laboratory kits for middle- and high-school teachers in rural New York.As a rapidly-growing, self-pollinating annual, E. cheiranthoides is an excellent model system for investigating the evolution of a new metabolic pathway for the production of cardenolides, a class of cardiac glycosides involved in herbivore defense. Modification of ubiquitous biosynthetic pathways of endogenous plant steroids, e.g. brassinosteroids, has likely been repeatedly selected for in the course of evolution to generate similar anti-herbivore toxins. This research will identify expansion and neofunctionalization of the enzyme families in E. cheiranthoides that normally contribute to primary metabolism in other crucifer species. Erysimum homologs of known cardenolide biosynthetic genes from other species will be identified using genome assemblies and characterized using structure-function-sequence analysis. Missing genes in the cardenolide pathway will be discovered through comparative metabolomics, transcriptomics, genomics, and forward genetic screens. Finally, the ecological "escape from herbivory" hypothesis will be tested by examining the role of cardenolides in host-insect interactions. Results from this research will be shared through publications, presentations at conferences, and inclusion in www.erysimum.org, a wallflower-specific website which will serve as a publicly accessible repository for all data related to this project.Keywords: biosynthesis biochemistry, plant biotic stress, comparative genomicsThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

这项行动资助了2018财年的NSF国家植物基因组计划生物学博士后研究奖学金。该研究金支持研究员在东道实验室的研究和培训计划，研究员还提出了扩大生物学参与的计划。Cynthia Holland博士的研究和培训计划的标题是“非模式十字花科植物糖芥（壁花）初级代谢中次级草食动物防御代谢物生物合成的进化”。“该奖学金的主办机构是博伊斯汤普森研究所，赞助科学家是乔治·詹德和卢卡斯·穆勒博士。为了保护自己免受食草昆虫的侵害，植物进化出了各种各样的化学防御。一类植物防御代谢物，被称为强心苷，在至少12个植物家族中发现，通过减缓收缩和增加捕食者心脏的泵送力来发挥作用。尽管这些化合物在治疗心律失常和充血性心力衰竭中具有治疗用途，但对于任何植物物种，都不知道强心苷生物合成的完整途径。本计画将利用具强心甙的虫实墙花（糖芥）来鉴定这些化合物的生物合成途径基因。这些结果将有助于了解其他植物物种中防御性化学物质的进化，包括玉米，大豆和小麦等重要作物。培训目标包括代谢组学、遗传学、基因表达技术和生物信息学。 更广泛的影响包括通过NSF资助的REU项目指导，向代表性不足的学生介绍基因组学和化学生态学研究，在扬克斯（纽约）的一所城市高中向高中生推广，以及为纽约农村的初中和高中教师开发实验室工具包。cheiranthoides是一个很好的模式系统，用于研究一个新的代谢途径的演变，生产强心苷，一类强心苷参与草食动物的防御。内源性植物类固醇（例如油菜素类固醇）的普遍存在的生物合成途径的修饰可能在进化过程中被反复选择以产生类似的抗草食动物毒素。这项研究将确定扩大和新功能的酶家族在E。在其他十字花科植物中，这些植物通常参与初级代谢。将使用基因组组装鉴定来自其他物种的已知Cardenoprotein生物合成基因的糖芥同源物，并使用结构-功能-序列分析表征。将通过比较代谢组学、转录组学、基因组学和正向遗传筛选来发现cardenopathy途径中缺失的基因。最后，生态学的“逃避草食动物”的假设将通过检查的Cardenolides在寄主昆虫相互作用的作用进行测试。这项研究的结果将通过出版物、会议上的演讲和在www.erysimum.org上的收录来分享，这是一个专门的网站，将作为与该项目相关的所有数据的公开存储库。关键词：生物合成生物化学、植物生物胁迫、比较基因组学该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

项目成果

Independent evolution of ancestral and novel defenses in a genus of toxic plants (Erysimum, Brassicaceae)

• DOI: 10.7554/elife.51712
• 发表时间: 2020-04
• 期刊: eLife
• 影响因子: 7.7
• 作者: Tobias Züst;S. Strickler;Adrian F. Powell;Makenzie E. Mabry;H. An;M. Mirzaei;T. York;Cynthia K Holland;Pavan Kumar;Matthias Erb;Georg Petschenka;J. Gómez;F. Perfectti;C. Müller;J. C. Pires;Lukas A Mueller;G. Jander