Excellence in Research: Elucidating uptake mechanisms of silver/zinc oxide nanoparticles into food crops and transport through soil ecosystem

纳米技术是现代科学技术中最具创新性的进步之一，有望给包括农业在内的各种行业带来革命性的变化。用于农业应用的新型纳米化肥、农药、传感器和养分输送系统正在迅速增加。然而，支配他们命运和风险的根本机制仍然知之甚少。为了解决农业纳米颗粒的生物利用度、去向和对食品安全的风险，该项目将利用两种粮食作物和两种农业中常用的纳米颗粒来研究纳米颗粒在植物-土壤生态系统中的积累和转化。这项拟议研究产生的结果将解决社会对纳米技术在农业应用中的潜在好处、生态影响和局限性的关键关注，并显著促进我们对纳米技术在农业中应用的理解。这个多学科、多机构合作的项目还将使密苏里州林肯大学加强其科学、技术、工程和数学教育和研究能力。林肯大学是1890年授予土地的，也是美国历史上最古老的黑人学院和大学之一。通过这个项目，研究人员将培训未被充分代表和未得到充分服务的学生，使他们在科学、技术、工程和数学职业生涯中发挥领导作用，解决复杂的、新出现的环境问题，为多样化的劳动力做出贡献。含有金属工程纳米颗粒的纳米技术支持的农用化学品，如银和氧化锌纳米颗粒，在农业应用中特别受欢迎。了解它们对环境的影响、与作物或微生物群落的相互作用机制以及与植物-土壤生态系统中共生的纳米颗粒的任何协同/拮抗效应是至关重要的。该项目将通过解决纳米技术与食品安全关系中的几个关键问题，直接促进纳米行为的科学知识。具体目标是：1)建立和验证用于各种介质中纳米颗粒检测和分析的单颗粒电感耦合等离子体质谱方法；2)阐明植物吸收和积累选定的纳米颗粒及其转化产物的机制；3)了解根际微生物群落对植物与纳米颗粒相互作用的作用；4)调查植物与共生纳米颗粒的相互作用；以及5)加强作为历史上黑人学院和大学的机构的科学、技术、工程和数学教育和研究能力。两种植物物种：中西部流行的作物玉米(Zea Mays)和常见的沙拉蔬菜生菜(Lactuca Sativa)将被选为代表作物物种。玉米是单子叶植物，生菜是双子叶植物；因此，由于两种植物的根结构不同，对纳米颗粒的吸收机制可能会有所不同。银纳米颗粒由于其抗菌性能，已成为各种农用化学品的常见成分。锌是植物必需的微量营养素，纳米氧化锌也显示出一定的抗菌性能，被开发为一种新型肥料来缓解农艺作物的缺锌问题。单粒子电感耦合等离子体质谱是一种用于纳米粒子分析的前沿、先进技术。该项目代表了一项整合了农作物、纳米颗粒和关键实验技术的多学科研究。这项研究的新方法和发现可以扩展到其他纳米颗粒-作物系统，以促进我们对纳米技术对植物生长和食品安全的影响的知识，这是社会面临的一个关键挑战。从拟议项目中获得的见解将为纳米颗粒在植物-土壤生态系统中的命运和影响提供可靠的科学证据，从而极大地有助于了解纳米技术在农业中的应用。这个多机构合作项目还将为代表不足和服务不足的学生提供巨大的好处，并为多样化的科学、技术、工程和数学工作队伍做出贡献。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。

Nanotechnology is one of the most innovative advancements in modern science and technology and promises to revolutionize a variety of industries including agriculture. Novel nano-based fertilizers, pesticides, sensors and nutrient delivery systems for agricultural applications have been rapidly increasing. However, the underlying mechanisms governing their fate and risks are still poorly understood. In an effort to address the bioavailability, fate, and risks to food safety of agricultural nanoparticles, this project will utilize two food crops and two commonly used nanoparticles in agriculture to study the accumulation and transformation of nanoparticles in the plant-soil ecosystem. Findings generated from the proposed research will address critical societal concerns on the potential benefits, ecological impacts, and limitations of nanotechnology for agricultural applications and significantly advance our understanding of nanotechnology applications in agriculture. This multi-disciplinary, multi-institution collaborative project will also enable Lincoln University of Missouri, an 1890 land-grant and one of the nation's Historically Black Colleges and Universities, to strengthen its science, technology, engineering and mathematics education and research capacity. Through this project, the investigator will train underrepresented and underserved students for science, technology, engineering and math career leadership roles in addressing complex, emerging environmental issues, contributing to a diverse workforce.Nanotechnology-enabled agrichemicals containing metallic engineered nanoparticles such as silver and zinc oxide nanoparticles are particularly popular for agricultural applications. It is critically important to understand their environmental impacts, interactive mechanisms with crops or microbial communities, and any synergistic/antagonistic effect with co-occurring nanoparticles in the plant-soil ecosystem. This project will directly contribute to advancing the scientific knowledge of nano behavior by addressing several key questions in the nanotechnology-food safety nexus. Specific objectives are to: 1) develop and validate single particle inductively coupled plasma mass spectrometry method for nanoparticle detection and analysis in various media; 2) elucidate the mechanisms for plant uptake and accumulation of selected nanoparticles and their transformed products; 3) understand the role of rhizosphere microbial community on plant-nanoparticle interactions; 4) investigate the interactions of plants with co-occurring nanoparticles; and 5) enhance the science, technology, engineering and mathematics education and research capacity at an institution designated as a Historically Black College and University. Two plant species: corn (Zea mays), a popular crop in the Midwest, and lettuce (Lactuca sativa), a common salad vegetable, will be selected as representative crop species. Corn is a monocot and lettuce a dicot; therefore, the uptake mechanisms of nanoparticles may differ between the two plants due to their different root structures. Silver nanoparticles have become a common ingredient in a variety of agrichemicals due to their antimicrobial property. Zinc is an essential micronutrient for plants, and zinc oxide nanoparticles have also displayed some antimicrobial properties and been explored as a novel fertilizer to reduce the zinc deficiency for agronomic crops. The single particle inductively coupled plasma mass spectrometry is a cutting-edge, advanced technology used for nanoparticle analysis. This project represents a multi-disciplinary research with integration of crop plants, nanoparticles, and key experimental technologies. The novel methods and findings from this study could be expanded to other nanoparticle-crop systems to advance our knowledge on the impacts of nanotechnology on plant growth and food safety, a critical challenge facing society. The insights obtained from the proposed project will greatly contribute to the knowledge of nanotechnology applications in agriculture by providing solid, scientific evidence on the fate and impacts of nanoparticles in the plant-soil ecosystems. This multi-institution collaborative project will also provide immense benefits to underrepresented and underserved students and contribute to a diverse science, technology, engineering and math workforce.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.