CAREER: Understanding the function and regulation of amino acid transporters in plant innate immunity

植物是非常有弹性的有机体，能够感知挑战并做出适应性反应，包括各种不断试图利用它们所拥有的资源的微生物。了解植物如何实现对微生物感染的长期和广泛的抵抗力有望揭示增强农作物以及具有生态重要性的植物物种对微生物疾病抵抗力的新方法，鉴于到2050年预计将有90亿人需要食物和健康的栖息地，这是一个关键的挑战。目前的研究旨在了解植物如何应对微生物入侵以限制感染。在树叶间隙繁殖的细菌微生物从植物宿主那里获得它们所需的所有代谢物和营养。因此，了解植物如何调节叶片间隙的组成，将有助于更广泛地了解--并可能发现--植物抵抗感染的方式。此外，拟议的研究将为K-12培训教师提供研究经验，从而促进从大学到弗吉尼亚州到地区公立学校的长期研究合作。通过这项研究，这项研究将让数百名高中生接受基于探究的开放式实验，以促进高阶思维技能。虽然少数适应良好的微生物物种能够感染目标植物物种并引起疾病，但大多数植物对大多数病原体都具有抗性。这种广谱耐药性部分归因于对微生物相关分子模式(MAMP)的感知以及随后激发的MAMP触发的免疫(MTI)抑制微生物生长。虽然MAMP激活的植物信号程序越来越为人所知，但植物限制微生物生长的机制仍然难以捉摸。皮丹娜发现，MTI导致叶质外体中改变细菌生长的氨基酸(AAs)浓度。PI的研究重点是了解AAs转运蛋白(AAT)如何改变AA浓度，从而限制拟南芥中紫丁香疫霉的生长。这种反应的一部分是通过水杨酸(SA)介导的AATS转录调控来协调的。PI假设：1)AATS在MTI期间改变了叶片质膜中AAs的浓度，2)SA在MTI期间协调AATS的表达和/或活性。本实验的目的是：1)从生化和时空上表征与MTI有关的AATS；2)研究SA在AATS调控中的作用；3)评估AATS在调节紫丁香松材线虫生长中的作用。PI的长期研究目标是了解植物对感染具有持久抵抗力的机制。PI的长期教育目标是通过提供尖端的研究培训和促进与职前科学教师的长期合作来改善K-12 STEM教育。该奖项反映了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。

Plants are remarkably resilient organisms that perceive and adaptively respond to challenges, including a broad range of microbes that constantly attempt to use the resources they hold. Understanding how plants achieve long-lasting and broad-range resistance to microbial infection promises to reveal new ways to enhance resistance to microbial disease in crops as well as in ecologically important plant species, a critical challenge in view of the projected 9 billion people that will need food and healthy habitats by the year 2050. The current research aims to understand how plants respond to microbial invaders to restrict infections. Bacterial microbes that multiply in the interstitial space of the leaf obtain all the metabolites and nutrients that they need from their plant hosts. Thus, understanding how plants regulate the composition of the leaf interstitial space will allow for a broader understanding – and potential discovery – of way that plants resist infection. In addition, the research proposed will provide K-12 teachers-in-training with research experience, thereby fostering long-term research collaborations to extend from the University to Virginia to area public schools. Through this, the research presented will expose hundreds of high-school students to inquiry-based, open-ended experimentation that promotes high-order thinking skills. Although a small number of well-adapted microbial species are able to infect target plant species and cause disease, most plants are resistant to most pathogens. This broad-spectrum resistance is in part attributed to the perception of Microbe-Associated Molecular Patterns (MAMPs) and the subsequent elicitation of MAMP-Triggered Immunity (MTI) that suppresses microbial growth. While the MAMP-activated plant signaling programs are increasingly well understood, the mechanisms by which plants restrict microbial growth remain elusive. PI Danna discovered that MTI leads to changes in the concentrations of amino acids (AAs) in the leaf apoplast that alter bacterial growth. The PI’s research focuses on understanding how AAs transporters (AATs) modify AA concentrations that restrict of P. syringae’s growth in Arabidopsis. Part of this response is coordinated by salicylic acid (SA) mediated transcriptional regulation of AATs. The PI hypothesizes that: 1) AATs alter the concentration of AAs in the leaf apoplasm during MTI, and 2) SA coordinates AATs expression and/or activity during MTI. The proposed experiments aim to: 1) Biochemically and spatio-temporally characterize the AATs that contribute to MTI; 2) Investigate the role of SA in the regulation of AATs; 3) Assess the role of AATs in modulating P. syringae’s growth. The PI’s long-term research goal is to understand the mechanisms that provide plants with long lasting resistance to infections. The PI’s long-term educational goal is to improve K-12 STEM education through providing cutting-edge research training and fostering long-term collaborations with pre-service science teachers.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.