Collaborative Research: PurSUiT: Species diversity and evolution of parasitic microfungi

真菌对生态系统功能至关重要，几乎无处不在，并与各种生物形成复杂的关系，包括原核生物、藻类、植物、无脊椎动物、脊椎动物和其他真菌。尽管如此，真菌是真核生物中采样最不足、记录最差的主要谱系，尽管总物种估计保守地在150万到610万之间。这种不确定性反映了关于真菌分布的许多知识差距，特别是关于不可培养真菌、微观真菌（微真菌）、寄生真菌和热带真菌的范围和程度。该项目将记录两类真菌的多样性，这两类真菌代表了我们知识上的主要空白：一类是与昆虫有关的不可培养微真菌，称为Labouls；另一类是与植物有关的不可培养微真菌，称为Rust fungus。通过与其动物和植物宿主的有益和有害的相互作用，预计Labouls和Rust真菌成员将对生态系统的健康和功能产生深远的影响。研究小组将探索热带和温带地区的几个全球栖息地，这些栖息地以前没有对这些真菌进行过调查。在这个项目中，预计将发现和描述数百个新物种。除了加强地球上记录的生物多样性外，该项目还将解决这两个群体的“生命之树”问题，并利用这些信息解决有关真菌进化的长期问题。更广泛的影响包括研究生和本科生培训、国际研讨会以加强美国和本地研究人员之间的合作，以及通过“蝙蝠之夜”和“捉蟑螂”实地考察活动向公众宣传。研究这些真菌谱系有几个原因：1)它们都代表了来自热带地区的文献很少的群体；2)两者都代表了通常应用的基于培养和高通量测序工作无法检测到的群体；3)通过对已知物种的多位点分析，这两个类群在系统发育上都没有得到解决；4)它们都是专性寄生谱系，很少被研究，但预计会对生态系统产生深远的影响；5)两者都是或与异源真菌有关（需要两个不同的宿主），这种现象在真菌中极为罕见。一个由美国和其他全球真菌专家组成的互补团队，从初级科学家到高级科学家，设计了一种实验方法，包括从热带和热带外地区进行多位点系统发育、系统基因组学、比较基因组学和统计分析的标准化采样策略，以：1)确定未包括在任何其他估计中的专性微寄生真菌的准确估计是否会影响总体真菌物种估计；2)寄生微真菌是否遵循其他真菌类群的反纬度梯度；3)通过整合“缺失”谱系来解决长期未解决的系统发育节点。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Fungi are essential to ecosystem functioning, occur virtually everywhere, and form complex relationships with diverse organisms including prokaryotes, algae, plants, invertebrates, vertebrates, and other fungi. Nonetheless, fungi are the most undersampled and poorly documented major lineage of eukaryotes, even though total species estimates range conservatively from 1.5–6.1 million species. This uncertainty reflects numerous gaps in knowledge about fungal distributions, especially regarding range and extent of unculturable fungi, microscopic fungi (microfungi), parasitic fungi, and tropical fungi. This project will document diversity of fungi in two groups that represent major gaps in our knowledge—the first are unculturable microfungi that associate with insects, called Labouls, and the other are unculturable microfungi that associate with plants, called Rust Fungi. Members of Labouls and Rust Fungi are expected to have profound effects on ecosystem health and functioning through both beneficial and harmful interactions with their animal and plant hosts. The research team will explore several global habitats in tropical and temperate regions that have not previously been surveyed for these fungi. It is expected that hundreds of new species will be discovered and described during this project. In addition to enhancing the documented biodiversity on the planet, this project will resolve the “tree of life” for both groups and use this information to resolve long-standing questions regarding the evolution of the Fungi. Broader impacts include graduate and undergraduate training, international workshops to enhance collaboration between US and local researchers, and outreach to the public through “Bat Night” and “Roach Hunt” field trips.These fungal lineages are being studied for several reasons: 1) both represent groups poorly documented from tropical world regions; 2) both represent groups that are not detected by commonly applied culture-based and high throughput sequencing efforts; 3) neither group has been resolved, phylogenetically, by application of multi-locus analyses of known species; 4) both represent obligately parasitic lineages that are rarely studied but expected to have profound effects on ecosystems; and 5) both are or are related to heteroecious fungi (requiring two different hosts), a phenomenon that is extremely rare in Fungi. A complementary team of US and other global experts on these fungi, ranging from junior to senior scientists, have designed an experimental approach that includes standardized sampling strategies from tropical and extra-tropical regions with multi-locus phylogenetic, phylogenomic, comparative genomic, and statistical analyses to: 1) Determine whether accurate estimates from obligate microparasitic fungi, not included in any other estimates, will affect overall Fungi species estimates; 2) whether parasitic microfungi follow the reverse latitudinal gradient posited for other fungal groups; and 3) resolve long-standing unresolved phylogenetic nodes by the incorporation of “missing” lineages.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.