IOS EDGE: Development of genetic and genomic resources for milkweed, Asclepias syriaca and Asclepias curassavica

IOS EDGE：马利筋、马利筋和马利筋遗传和基因组资源的开发

• 批准号: 1645256
• 负责人: Georg Jander
• 金额: $ 102万
• 依托单位: Boyce Thompson Institute Plant Research
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-15 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1645256&HistoricalAwards=false
• 关键词: IOS; EDGE; Development; genetic; genomic

Milkweed plants are well-known for their iconic interactions with monarch butterflies. Although milkweeds produce toxins that are lethal to most insects, monarch butterfly caterpillars are quite resistant and even store milkweed toxins for their own defense against predators like birds. As is indicated by the milkweed genus name, Asclepias, which is derived from Asclepius, the Greek god of healing, Native Americans used these plants to treat a variety of medical ailments. Several studies have shown that milkweeds are rich sources of novel chemical compounds that not only provide defense against insects, but also have potential medical applications. In this project the investigators will develop new resources to investigate the function of specific genes in both common milkweed and tropical milkweed. Methods will be developed to knock out or overexpress specific milkweed genes in a targeted manner. Genome sequencing of two milkweed species, together with natural variation in milkweed gene expression and chemical content, will enable the discovery of new genes involved in defense against herbivory and the production of medically relevant plant metabolites. The resources that will be developed through this project will be made publicly available as they are being generated, with no restrictions limiting their use. The project also will involve training high school students and undergraduate summer interns, which will prepare them for future research careers in industry, academia, or government service.The further development of Asclepias syriaca (common milkweed) and Asclepias curassavica (tropical milkweed) as research model systems will require improved tools for studying the functions of individual genes. In this project, milkweed-specific protocols will be developed for: (i) transient gene expression using Agrobacterium infiltration, (ii) virus-induced silencing of endogenous gene expression, (iii) targeted mutagenesis using CRISPR/Cas9, (iv) stable transformation in tissue culture, (v) regeneration of plants from callus, and (vi) heritable modification of the milkweed genome. To facilitate functional analysis of milkweed genes, the A. syriaca and A. curassavica genomes will be assembled using Pacific Biosciences DNA sequencing. Assembled contigs will be ordered and assigned to specific chromosomes using classical genetic maps and BioNano optical maps. Milkweed genes will be identified and annotated through in silico comparisons and deep sequencing of RNA from different tissue types. Genotyped A. syriaca and A. curassavica genetic mapping populations will enable quantitate trait locus mapping of any phenotypic or molecular trait that varies in the constituent lineages. Plant gene expression and metabolite content varies dramatically in different tissue types and in response to environmental stimuli. In particular, insect attack induces the production of a wide variety of biologically active plant metabolites. Transcriptomic and metabolomic analysis of six A. syriaca and A. curassavica tissue types, with and without herbivory treatment, will provide a broad overview of the genetic and metabolic potential of these species. Molecular protocols, genome sequences, transcriptome data, and correlative analyses linking the transcriptomes, metabolomes, and other milkweed phenotypes will be displayed on the project website, www.milkweedbase.net.

马利筋植物因其与帝王蝶的标志性相互作用而闻名。尽管马利筋产生的毒素对大多数昆虫来说是致命的，但帝王蝶毛毛虫具有很强的抵抗力，甚至储存马利筋毒素以防御鸟类等捕食者。正如马利筋属名称 Asclepias（源自希腊治愈之神 Asclepius）所示，美洲原住民使用这些植物来治疗各种医疗疾病。多项研究表明，马利筋是新型化合物的丰富来源，这些化合物不仅可以防御昆虫，而且具有潜在的医学应用。在该项目中，研究人员将开发新资源来研究普通马利筋和热带马利筋中特定基因的功能。将开发有针对性地敲除或过度表达特定马利筋基因的方法。对两种马利筋物种的基因组测序，加上马利筋基因表达和化学含量的自然变异，将有助于发现参与防御草食动物和产生医学相关植物代谢物的新基因。通过该项目开发的资源将在生成时公开，且不限制其使用。该项目还将培训高中生和本科生暑期实习生，为他们未来在工业界、学术界或政府服务领域的研究生涯做好准备。作为研究模型系统的马利筋（Asclepias syriaca）和马利筋（热带马利筋）的进一步开发将需要改进的工具来研究个体基因的功能。在该项目中，将开发针对马利筋的方案：(i) 使用农杆菌渗透进行瞬时基因表达，(ii) 病毒诱导的内源基因表达沉默，(iii) 使用 CRISPR/Cas9 进行靶向诱变，(iv) 组织培养中的稳定转化，(v) 从愈伤组织再生植物，以及 (vi) 马利筋基因组的可遗传修饰。为了促进马利筋基因的功能分析，将使用 Pacific Biosciences DNA 测序来组装 A. syriaca 和 A. curassavica 基因组。将使用经典遗传图谱和 BioNano 光学图谱对组装的重叠群进行排序并分配给特定染色体。将通过对不同组织类型的 RNA 进行计算机比较和深度测序来识别和注释马利筋基因。经过基因分型的 A. syriaca 和 A. curassavica 遗传作图群体将能够对组成谱系中变化的任何表型或分子性状进行定量性状基因座作图。植物基因表达和代谢物含量在不同的组织类型和对环境刺激的反应中存在显着差异。特别是，昆虫攻击会诱导产生多种具有生物活性的植物代谢物。对六种 A. syriaca 和 A. curassavica 组织类型（无论是否经过食草处理）进行转录组学和代谢组学分析，将为这些物种的遗传和代谢潜力提供广泛的概述。分子方案、基因组序列、转录组数据以及连接转录组、代谢组和其他马利筋表型的相关分析将在项目网站 www.milkweedbase.net 上显示。

项目成果

Advances in understanding the long-term population decline of monarch butterflies

• DOI: 10.1073/pnas.1903409116
• 发表时间: 2019-03
• 期刊: Proceedings of the National Academy of Sciences
• 作者: A. Agrawal

Hybridization between Asclepias purpurascens and Asclepias syriaca (Apocynaceae): A cause for concern?1

紫萝苓和叙利亚萝藦（夹竹桃科）之间的杂交：值得关注的原因吗？1

• DOI: 10.3159/torrey-d-18-00050.1
• 发表时间: 2019
• 期刊: The Journal of the Torrey Botanical Society
• 作者: Broyles, Steven B.;Elkins, Geordie
• 通讯作者: Elkins, Geordie

Erysimum cheiranthoides, an ecological research system with potential as a genetic and genomic model for studying cardiac glycoside biosynthesis

Erysimum cheiranthoides，一种生态研究系统，具有作为研究强心苷生物合成的遗传和基因组模型的潜力

• DOI: 10.1007/s11101-018-9562-4
• 发表时间: 2018
• 期刊: Phytochemistry Reviews
• 影响因子: 7.7
• 作者: Züst, Tobias;Mirzaei, Mahdieh;Jander, Georg
• 通讯作者: Jander, Georg

What doesn’t kill you makes you stronger: The burdens and benefits of toxin sequestration in a milkweed aphid

杀不死你的会让你变得更强大：马利筋蚜虫隔离毒素的负担和好处

• DOI: 10.1111/1365-2435.13144
• 发表时间: 2018
• 期刊: Functional Ecology
• 影响因子: 5.2
• 作者: Züst, Tobias;Mou, Sophie;Agrawal, Anurag A.;Biere, ed., Arjen
• 通讯作者: Biere, ed., Arjen

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