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

真菌对生态系统的功能至关重要，几乎无处不在，并与包括原核生物、藻类、植物、无脊椎动物、脊椎动物和其他真菌在内的各种生物形成复杂的关系。尽管如此，真菌是采样最少、记录最少的真核生物的主要谱系，尽管总物种估计保守地在150-610万种之间。这种不确定性反映了关于真菌分布的许多知识空白，特别是关于不可培养真菌、微型真菌、寄生真菌和热带真菌的范围和程度。这个项目将记录两组真菌的多样性，这两组真菌代表了我们知识的主要差距-第一组是与昆虫有关的不可培养的微型真菌，称为Labouls，另一组是与植物有关的不可培养的微型真菌，称为锈菌。Labouls和锈菌的成员预计将通过与其动植物宿主的有益和有害的相互作用，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，这些栖息地以前从未被调查过这些真菌。预计在这个项目中将发现和描述数百个新物种。除了加强地球上已记录的生物多样性，该项目还将解决这两个群体的“生命之树”，并利用这些信息来解决长期存在的关于真菌进化的问题。更广泛的影响包括研究生和本科生培训，加强美国和当地研究人员合作的国际研讨会，以及通过“蝙蝠之夜”和“蟑螂狩猎”实地旅行向公众宣传。这些真菌谱系被研究的原因有几个：1)两个都代表了热带世界地区记录很少的群体；2)两个群体都代表了通常应用的基于培养的高通量测序工作没有发现的群体；3)两个群体都没有通过应用已知物种的多基因座分析从系统发生学上得到解决；4)两个群体都代表了几乎不被研究但预计会对生态系统产生深远影响的寄生血统；和5)两者都是或与异株真菌有关(需要两个不同的寄主)，这种现象在真菌中极其罕见。一个由美国和其他全球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，其中包括来自热带和非热带地区的标准化采样策略，具有多基因座系统发育、系统发育、比较基因组学和统计分析，以：1)确定专性微寄生真菌的准确估计是否会影响真菌物种的总体估计；2)寄生微真菌是否遵循对其他真菌类群设定的反向纬度梯度；3)通过纳入“缺失的”序列来解决长期悬而未决的系统发育节点。这一裁决反映了NSF的法定使命，并通过使用基金会的智力优势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.