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，霸王花这种罕见但巨大的恶臭栗色花朵脱颖而出，欺骗性地引诱腐尸蝇，因此有了俗称“尸花”。 与大多数植物不同，霸王花是一种专性植物寄生虫，没有茎、根和叶，也没有光合作用，而光合作用被认为是植物的特征。只有热带葡萄藤感染崖爬藤-只有少数几个品种-这是未知的原因。尽管是一个富有魅力的保护象征，但西方植物园中还没有种植拉弗斯，因为它的种植方式几乎还不为人所知。该项目旨在了解Rafflesia宿主选择的生态学-Tetrastigma宿主中的哪些分子和微生物使它们与非宿主相比容易受到Rafflesia感染，以及如何使用这些基本信息来指导繁殖。相反，该项目将产生有关Tetrastigma增强宿主免疫功能的代谢和微生物过程的数据，为什么某些物种不被Rafflesia寄生，以及如何将这些知识应用于Tetrastigma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，促进他们在生物多样性科学方面的职业生涯，同时为菲律宾的土著社区提供能力建设，收集样本。这种对基础科学的理解可能有一天会让植物界的熊猫Rafflesia在植物园中盛开，促进教育和保护。时间是至关重要的，因为一旦灭绝，尸体花就不能再复活了。霸王花（Rafflesiaceae，Malpighiales）是一种内生全寄生虫，完全依赖其宿主葡萄藤Tetrastigma（Vitaceae，Vitales）提供营养，一生都生活在其中，只有开花时才出现。然而，并非所有崖爬藤属物种都支持霸王花属感染。该项目旨在了解Rafflesia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物种系统将澄清使某些Tetrastigma物种的共同模式。宿主与非宿主，揭示了不同的Rafflesia spp.在感染过程中同样改变宿主生态，以及破译物种系统之间的代谢和微生物特性，这可以解释霸王花的宿主选择。在农业中，嫁接的成功取决于接穗和砧木的密切关系，但与其宿主属于不同目的的Rafflesia如何成功地逃避宿主免疫，以及如何将这些基本信息应用于防止作物中的嫁接不亲和性？由此产生的数据也将揭示收敛进化的程度相比，其他主机-寄生虫系统，如果有类似的主机降解代谢产物在不同的寄生植物谱系的异养进化。这些数据将阐明宿主化学型和植物调节微生物内生菌，可以促进和维持Rafflesia感染，因此，Rafflesia园艺迁地保护，同时获得可能有利于其他农作物的见解。该奖项反映了NSF的法定使命，并已被认为是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的支持。