Fate of Cadmium and Arsenic Under Engineered Physico-Chemical Gradients in the Soil-Water-Rice Nexus

土壤-水-水稻关系中工程物理化学梯度下镉和砷的归宿

基本信息

批准号：
1930806
负责人：
Angelia Seyfferth
金额：
$ 35.39万
依托单位：
University of Delaware
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-10-01 至 2023-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1930806&HistoricalAwards=false
关键词：
Fate Cadmium Arsenic Under Engineered

项目摘要

Rice is a staple food for half the world's population. Despite its importance, the yield and quality of rice are threatened by arsenic and cadmium uptake from soil. Rice will uptake and concentrate arsenic when it is grown under conventional soil flooding, because arsenic is released into the water from biogeochemical reactions in the soil. This process can happen even when soil arsenic concentrations are low. Although minimizing soil flooding can decrease arsenic contamination of rice and even save water resources, doing so can increase rice grain uptake of cadmium from the soil. The goal of this research project is to develop methods that simultaneously limit rice uptake of both arsenic and cadmium. Manganese(II) is less toxic to plants than cadmium or arsenic and has been recently shown to share a root transport pathway with cadmium. Therefore, it should be possible to exploit the geochemical characteristics of manganese to decrease uptake of cadmium into the plant via engineered soil electrochemistry. This research project takes a multidisciplinary approach that incorporates geochemistry and plant biology methods and also will utilize resources at the NSF-funded Rice Investigation, Communication, and Education (RICE) Facility. This work will help train and foster the professional development of the next generation of STEM professionals to tackle the grand challenge of a sustainable food supply. Additional outreach efforts to high schools will increase scientific literacy of students and hopefully interest them in STEM careers.Rice is often the first food consumed by infants and is also a staple food for half of the global population. However, the yield and quality of rice are threatened by the uptake of toxic arsenic and cadmium during the soil flooding process integral to rice cultivation. Although arsenic cycling has been well studied over the last two decades, cadmium cycling and uptake by rice is less well understood. The hypothesis behind this research project is that controlling manganese(II) availability can provide an engineered solution to limit cadmium and arsenic uptake by rice. The specific objectives of this project are 1) to understand the role of increasing manganese(II) availability in decreasing cadmium uptake by rice in simple hydroponic systems; 2) to evaluate the impact of engineered redox states on dissolution, plant uptake, and localization of metal(loid)s including manganese, iron, cadmium, and arsenic, in rice plants grown in rice paddy mesocosms; and 3) to compare traditional redox measurements to novel techniques for quantifying indicators of reduction in soil (IRIS) films. IRIS film technology will be evaluated as a low-cost means for farmers to know when to drain their fields in order to restrict rice uptake of toxic metalloids. The outcomes of this research will transform the ability of rice agronomists, wetland scientists, farmers, and other stakeholders to prevent toxic metal uptake and thereby safeguard the food supply of billions of people. The results of this study should be applicable to many other plants beyond rice, because many plants also accumulate cadmium.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.

大米是世界上一半人口的主食。尽管水稻很重要，但其产量和质量却受到土壤中砷和镉的吸收的威胁。当水稻在常规土壤淹水下生长时，它会吸收并浓缩砷，因为砷会通过土壤中的生物地球化学反应释放到水中。即使土壤砷浓度较低，这个过程也会发生。尽管减少土壤淹水可以减少水稻的砷污染，甚至可以节省水资源，但这样做可以增加稻谷从土壤中吸收镉的量。该研究项目的目标是开发同时限制水稻吸收砷和镉的方法。锰 (II) 对植物的毒性低于镉或砷，并且最近已被证明与镉共享根部运输途径。因此，应该可以利用锰的地球化学特性，通过工程土壤电化学来减少植物对镉的吸收。该研究项目采用多学科方法，结合了地球化学和植物生物学方法，并将利用 NSF 资助的水稻调查、交流和教育 (RICE) 设施的资源。这项工作将有助于培训和促进下一代 STEM 专业人员的专业发展，以应对可持续食品供应的巨大挑战。对高中的额外推广工作将提高学生的科学素养，并希望他们对 STEM 职业感兴趣。大米通常是婴儿食用的第一种食物，也是全球一半人口的主食。然而，在水稻种植过程中的土壤淹水过程中，有毒砷和镉的吸收会威胁水稻的产量和质量。尽管过去二十年对砷循环进行了深入研究，但对镉循环和水稻吸收却知之甚少。该研究项目背后的假设是，控制锰 (II) 的可用性可以提供一种工程解决方案来限制水稻对镉和砷的吸收。该项目的具体目标是 1) 了解增加锰 (II) 可用性在减少简单水培系统中水稻对镉的吸收方面的作用； 2) 评估工程氧化还原态对稻田中生稻植物中锰、铁、镉和砷等金属（类）的溶解、植物吸收和定位的影响； 3) 将传统氧化还原测量与量化土壤还原指标 (IRIS) 膜的新技术进行比较。 IRIS 薄膜技术将被评估为一种低成本手段，让农民知道何时排干田地，以限制水稻对有毒非金属的吸收。这项研究的成果将改变水稻农学家、湿地科学家、农民和其他利益相关者防止有毒金属吸收的能力，从而保障数十亿人的粮食供应。这项研究的结果应该适用于水稻以外的许多其他植物，因为许多植物也会积累镉。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。