Evaluation of GE crop transgene adsorption to microplastics and downstream fate in the environment

由于转基因作物及其工程基因对人类健康和生态健康的未知影响，转基因作物一直存在争议。虽然转基因作物基因可以给作物带来有益的特性，比如抗农药，但如果它们被释放到环境中，有些基因也可能是有害的。抗生素耐药基因（ARGs）和沉默RNA基因是具有潜在危害的基因的两个例子。ARGs可增加环境中耐抗生素细菌的数量，这对公共卫生构成威胁。沉默RNA基因可以影响其他生物的遗传物质，这些基因在环境中的行为尚不清楚。像微塑料这样的持久性污染物已经被证明可以使这些基因在环境中更加稳定，使它们更有可能被广泛运输，并对有益的生物产生负面影响。本研究的目的是评估环境中附着在微塑料上的ARGs和沉默RNA基因的运输、持久性和摄取。了解转基因作物基因在环境中的表现对包括农业、医药和水处理在内的许多领域都很重要。通过制定基于风险的管理政策，通过最大限度地减少有害基因的传播来保护健康，这些结果具有促进知识和造福社会的强大潜力。由于转基因基因的最终命运和对周围环境的潜在影响的不确定性，转基因作物的使用一直存在争议。现代转基因作物中常见的转基因包括最近在污水处理厂和其他环境中检测到的ARGs和沉默rna。这些发现令人担忧，因为转基因对全球抗生素耐药性的贡献及其对环境微生物基因表达的潜在影响高度不确定。转基因最近也被证明可以吸附在废水处理厂和土壤中常见的微纳米级塑料（MNPs）的表面，这表明它们在环境中的运输潜力和抗降解能力可能比目前估计的要大。本研究的目的是了解MNPs如何影响环境中GEs的运输。这一目标将通过建模和实验相结合的方法来实现：i)量化转基因对MNPs、土壤和废水生物固体的吸附动力学；ii)评估关键环境因素对转基因基因持续和吸收的影响；iii)评估农业土壤中模式土壤细菌的转基因转运和转化。这项研究的成功完成直接解决了转基因对MNPs的吸附、它们在环境中的行为以及将实验数据转化为可被不同利益相关者群体利用的建模框架的重要研究空白。为研究生和本科生提供跨学科研究培训，以提高国家的STEM劳动力，从而为社会带来好处。通过为本科生提供学习模块，以及为华盛顿州帕卢斯地区的K-12学校开发以环境中的微塑料为重点的宣传材料，提高了科学素养，也带来了额外的好处。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。

Genetically engineered crops remain controversial because of the unknown impacts these crops and their engineered genes have on human and ecological health. While genetically engineered crop genes can give helpful traits like pesticide resistance to crops, some can also be harmful if they are released in the environment. Antibiotic resistance genes (‘ARGs’) and silencing RNA genes are two examples of genes that are potentially harmful. ARGs can increase the number of antibiotic resistant bacteria in the environment, which is a threat to public health. Silencing RNA genes can affect the genetic material of other organisms and the behavior of these genes in the environment is not well understood. Persistent pollutants like microplastics have been shown to make these genes more stable in the environment, making it more likely that they can be transported widely and negatively affect beneficial organisms. The goal of this research is to assess the transport, persistence, and uptake of ARGs and silencing RNA genes that are attached to microplastics in the environment. Understanding how genetically engineered crop genes behave in the environment is important for many fields including agriculture, medicine, and water treatment. The results have strong potential to advance knowledge and benefit society through the development of risk-based management policies to protect health by minimizing the spread of harmful genes. The use of genetically engineered (GE) crops has remained controversial due to uncertainty regarding the ultimate fate and potential impacts the engineered genes can have on the surrounding environment. Common transgenes contained in modern GE crops include ARGs and silencing RNAs that have recently been detected in wastewater treatment plants and other environments. These findings are concerning because transgene contributions to global antibiotic resistance and their potential impacts to gene expression in environmental microbes are highly uncertain. Transgenes have also recently been shown to adsorb to the surfaces of micro- and nano-scale plastics (‘MNPs’) that are frequently found in wastewater treatment plants and soils, suggesting their transport potential and resistance to degradation in the environment may be greater than currently estimated. The goal of this research is to understand how MNPs impact the transport of GEs in the environment. This goal will be achieved using a combined modeling and experimental approach to: i) Quantify transgene adsorption kinetics to MNPs, soils, and wastewater biosolids; ii) Assess the effects of key environmental factors on the persistence and uptake of GE transgenes; and iii) Evaluate transgene transport and transformation of model soil bacteria in agricultural soils. Successful completion of this research directly addresses important research gaps concerning transgene adsorption to MNPs, their behavior in the environment, and translation of experimental data to modeling frameworks that can be utilized by diverse stakeholder groups. Benefits to society result from interdisciplinary research training for graduate and undergraduate students to improve the Nation’s STEM workforce. Additional benefits result from enhanced scientific literacy through learning modules for undergraduate classes and development of outreach materials focused on microplastics in the environment for K-12 schools in the Palouse region of Washington State.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.