Metabolites and microbes of Tetrastigma: the ecology of host choice in Rafflesia and potential applications in ex situ conservation of the worlds largest flower

四柱花的代谢物和微生物：大王花寄主选择的生态学及其在世界最大花卉迁地保护中的潜在应用

• 批准号: 2346626
• 负责人: Jeanmaire Molina
• 金额: $ 27.96万
• 依托单位: Pace University New York Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2346626&HistoricalAwards=false
• 关键词: Metabolites; microbes; Tetrastigma; ecology; host

Amidst the dwindling rainforests of Southeast Asia, Rafflesia’s rare but massive malodorous maroon flower stands out, deceptively luring carrion flies, hence the common name, “corpse flower”. Unlike most plants, Rafflesia is an obligate plant parasite, bereft of stems, roots, and leaves, and devoid of photosynthesis, which supposedly defines plants. Solely infecting the tropical grape vine Tetrastigma—and only a few species of it—it is unknown why. Despite being a charismatic icon of conservation, there is no western botanic garden that has grown Rafflesia because it is still virtually unknown how. This project aims to understand the ecology of Rafflesia’s host choice—what molecules and microbes in Tetrastigma hosts make them susceptible to Rafflesia infection compared to non-hosts, and how this basic information may be used to guide propagation. Conversely, this project will yield data on the metabolic and microbial processes underlying enhanced host immune function in Tetrastigma, why certain species are not parasitized by Rafflesia, and how this knowledge can be applied in grapes, Tetrastigma’s close relative, to resist parasitic infections. Moreover, the project will engage underrepresented students and catalyze their careers in biodiversity science, while providing capacity building to indigenous communities in the Philippines where samples will be collected. This understanding of the fundamental science may one day allow Rafflesia—the panda of the plant world—to be in full bloom in botanic gardens, fostering education and conservation. Timing is critical, because once extinct, the corpse flower can no longer be revived.Rafflesia (Rafflesiaceae, Malpighiales) is an endophytic holoparasite, completely dependent on its host vine Tetrastigma (Vitaceae, Vitales) for nutrition, living inside it throughout its life and only emerging to flower. However, not all Tetrastigma species support a Rafflesia infection. The project aims to understand the ecology of Rafflesia’s host choice, focusing on the chemistry and microbiota unique to infected host species through metabolite profiling and metagenomic analysis. Comparing multiple Rafflesia-Tetrastigma species systems will clarify common patterns that make certain Tetrastigma spp. hosts versus non-hosts, reveal how different Rafflesia spp. similarly alter host ecology during an infection, as well as decipher the metabolic and microbial idiosyncrasies between species systems that could explain Rafflesia’s host choice. In agriculture, grafting success is dependent on how closely related the scion and rootstock are, but how does Rafflesia, belonging to a different order from its host, successfully evade host immunity, and how can this basic information be applied in preventing graft incompatibility in crops? Resulting data will also reveal the extent of convergent evolution compared to other host-parasite systems, if there are similar host-degrading metabolites in the evolution of heterotrophy in disparate lineages of parasitic plants. These data will elucidate host chemotypes and plant-regulating microbial endophytes that could facilitate and sustain a Rafflesia infection, and consequently, Rafflesia horticulture for ex situ conservation while gaining insights that could potentially benefit other agricultural crops.This 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.

在东南亚日益减少的雨林中，大王花这种罕见但巨大、恶臭的栗色花朵脱颖而出，它能欺骗性地引诱腐蝇，因此俗称“尸花”。 与大多数植物不同，大王花是一种专性植物寄生植物，没有茎、根和叶，也缺乏光合作用，而光合作用正是植物的特征。仅感染热带葡萄藤 Tetrastigma（且仅感染其中的少数品种），原因尚不清楚。尽管大王花是具有超凡魅力的保护标志，但西方还没有哪个植物园种植大王花，因为它的生长方式仍然未知。该项目旨在了解大王花宿主选择的生态学——与非宿主相比，四柱花宿主中的哪些分子和微生物使它们更容易受到大王花感染，以及如何利用这些基本信息来指导繁殖。相反，该项目将产生有关四柱花增强宿主免疫功能的代谢和微生物过程的数据，为什么某些物种不会被大王花寄生，以及如何将这些知识应用于四柱花的近亲葡萄，以抵抗寄生虫感染。此外，该项目将吸引代表性不足的学生并促进他们在生物多样性科学领域的职业生涯，同时为收集样本的菲律宾土著社区提供能力建设。对基础科学的这种理解有一天可能会让大王花——植物界的熊猫——在植物园中盛开，促进教育和保护。时机很关键，因为一旦灭绝，尸花就无法再复活。大王花（Rafflesiaceae，Malpighiales）是一种内生全寄生物，完全依赖其寄主藤蔓Tetrastigma（Vitaceae，Vitales）获取营养，一生都生活在其中，只开花。然而，并非所有四柱花物种都支持大王花感染。该项目旨在了解大王花宿主选择的生态学，通过代谢物分析和宏基因组分析，重点关注受感染宿主物种特有的化学和微生物群。比较多个 Rafflesia-Tetrastigma 物种系统将阐明使某些 Tetrastigma spp. 形成的常见模式。宿主与非宿主，揭示大王花属的不同之处。同样，在感染期间改变宿主生态，并破译物种系统之间的代谢和微生物特性，这可以解释大王花的宿主选择。在农业中，嫁接的成功与否取决于接穗和砧木的亲缘关系，但与寄主属于不同目的大王花是如何成功逃避寄主免疫的，又如何利用这一基本信息来预防作物的嫁接不亲和呢？如果寄生植物不同谱系的异养进化中存在类似的宿主降解代谢物，所得数据还将揭示与其他宿主-寄生虫系统相比趋同进化的程度。这些数据将阐明宿主化学型和植物调节微生物内生菌，它们可以促进和维持大王花感染，从而阐明大王花园艺的异地保护，同时获得可能有益于其他农作物的见解。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持 标准。