NSF Postdoctoral Fellowship in Biology FY 2017: Mites, microbes, and fungal pathogens: the ecology and evolution of an indirect defense trait

2017 财年 NSF 生物学博士后奖学金：螨虫、微生物和真菌病原体：间接防御性状的生态学和进化

• 批准号: 1708931
• 负责人: Ash Zemenick
• 金额: $ 13.8万
• 依托单位: Zemenick Ash T
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-10-01 至 2019-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1708931&HistoricalAwards=false
• 关键词: NSF; Postdoctoral; Fellowship; Biology; FY

This is an NSF Postdoctoral Research Fellowship in Biology, under the program Broadening Participation of Groups Under-represented in Biology. The fellow, Ash Zemenick, is conducting research and receiving training that is increasing the participation of groups underrepresented in biology. The fellow is being mentored by Marjorie Weber at the Michigan State University. This research explores how mites influence the pathogens of plants. Many plants have small tufts of hairs on the leaf ("domatia") that house mites. Mites can benefit plants by reducing the success of pathogens (bacteria and fungi), but the mechanisms and extent of variation are not well understood. Mites can directly reduce success of pathogens by eating them. Also, by influencing the abundance of microbes that inhibit pathogens, mites may indirectly influence pathogen success. Finally, because not all plants have domatia, the way in which mites and/or microbes influence pathogens may vary across plant species. The fellow is disentangling these effects using an experiment that manipulates the access of mites to plants, and the occurrence of potential pathogens. This research will increase the understanding of these widespread ecological interactions, and contribute to sustainable pathogen management in agroecosystems. This project also includes two explicit broader impacts that address some stereotypes that fuel underrepresentation in biology. First, the fellow has experienced life as a woman and transgender person, and thus serves as a role model in mentoring undergraduates involved in research. Second, the fellow is developing a repository of teaching materials to humanize biology and biologists by highlighting how research applies to societal issues and what it's like to be a biologist. The fellow is using examples provided by biologists that self-identify as members of underrepresented groups in STEM (e.g. in terms of race, ethnicity, gender, income, nationality, immigrant status, cognitive and physical ability, etc.). The fellow is conducting manipulative experiment to understand how mites influence pathogen success directly (via consumption) and/or indirectly (via an altered microbial community composition that is less invasible). Leaves from 20 species of grapes (Vitis) will be experimentally manipulated with four treatments. Two (T1 and T2) will block mites, and two (T3 and T4) will have mites. After 2 weeks, half of all leaves will be harvested to assess leaf microbial communites. Fungal and bacterial DNA will be amplified using barcoded ITS and 16S primers and the resulting multiplexed amplicons will be subject to Illumina sequencing. A difference between no-mite (T1 and T2) and mite (T3 and T4) leaf microbial communities would empirically demonstrate that domatia-inhabiting mites influence leaf microbe community structure, and could therefore indirectly influence pathogen success in Vitis. The other half of replicates will remain in the field, with mites allowed only on T2 and T4. All leaves will be challenged with powdery mildew. If mite presence lowers pathogen infection of Vitis leaves, then leaves from T2-T4 will have lower infestation of powdery mildew than control (T1) leaves. If this reduction in pathogen infection is through direct consumption rather than indirectly through a modified leaf microbe community, then T2 and T4 leaves will have lower powdery mildew infestation than T2 leaves. To evaluate patterns of microbial community evolution and pathogen resistance across leaves, multi- and unidimensional comparative phylogenetic models will be used to assess whether microbial community composition and structure, as well as pathogen resistance, are evolutionarily correlated with domatia presence and size across Vitis species. If domatia presence and size are correlated with powdery mildew resistance across the phylogeny, there will be evidence for either: A) the selective environment for domatia included pathogen resistance, or B) evolution of domatia selected for the loss of direct pathogen resistance.

这是NSF生物学博士后研究奖学金，在该计划下，扩大了生物学中代表性不足的群体的参与。这位名叫Ash Zemenick的研究员正在进行研究和接受培训，这将增加生物学中代表性较低的群体的参与。密歇根州立大学的马乔里·韦伯正在指导他。这项研究探索了螨类如何影响植物的病原体。许多植物在寄生螨类的叶子上有一小簇毛发。螨类可以通过减少病原体(细菌和真菌)的成功而使植物受益，但其机制和变异程度尚不清楚。螨类可以通过捕食病原体来直接降低病原体的成功率。此外，通过影响抑制病原体的微生物的数量，螨类可能间接影响病原体的成功。最后，因为并不是所有的植物都有寄生虫，所以螨类和/或微生物影响病原体的方式可能会因植物物种而异。这位研究员正在通过一项实验来解决这些影响，该实验操纵螨类进入植物，并控制潜在病原体的发生。这项研究将增加对这些广泛的生态相互作用的理解，并有助于农业生态系统中病原菌的可持续管理。这个项目还包括两个明显的更广泛的影响，以解决一些助长生物学中代表性不足的刻板印象。首先，这位研究员经历了女性和变性人的生活，因此在指导参与研究的本科生方面起到了榜样作用。其次，这位研究员正在开发一个教材资源库，通过强调研究如何应用于社会问题以及成为生物学家是什么感觉，来使生物学和生物学家人性化。这位研究员使用了生物学家提供的例子，这些生物学家自认为是STEM中代表性不足的群体的成员(例如，在种族、民族、性别、收入、国籍、移民身份、认知和身体能力等方面)。该研究员正在进行操纵性实验，以了解螨类如何直接(通过消耗)和/或间接(通过较少入侵的改变的微生物群落组成)影响病原体的成功。来自20种葡萄(葡萄属)的叶子将通过四种处理进行实验操作。两个(T1和T2)会阻止粉尘，两个(T3和T4)会有粉尘。2周后，将收获一半的叶片，以评估叶片微生物群落。真菌和细菌的DNA将使用条形码ITS和16S引物进行扩增，得到的多重扩增产物将经过Illumina测序。无叶螨(T1和T2)和叶螨(T3和T4)叶片微生物群落的差异将经验地证明，寄生叶螨影响叶片微生物群落结构，从而间接影响葡萄病原菌的成功。另一半的重复将留在田间，只允许在T2和T4上有螨虫。所有的叶子都会受到白粉病的侵袭。如果尘螨的存在降低了葡萄叶片的病原菌侵染率，那么T2-T4叶片的白粉病侵染率将低于对照(T1)叶片。如果病原菌侵染的减少是通过直接消耗而不是通过改良的叶片微生物群落间接实现的，那么T2和T4叶片的白粉病侵染率将低于T2叶片。为了评估叶片中微生物群落的进化模式和对病原菌的抗性，将使用多维和一维比较系统发育模型来评估微生物群落的组成和结构以及病原菌的抗性是否与葡萄属物种间的寄生虫的存在和大小存在进化相关。如果DOMATIA的存在和大小与整个系统发育过程中的白粉病抗性相关，则将有证据表明：A)DOMATIA的选择环境包括病原菌抗性，或B)DOMATIA的进化被选择为失去直接的病原菌抗性。