Biosensors for Environmental Contaminants

描述(由申请人提供)：土壤铅是一种主要的环境健康危害，特别是对儿童。目前检测土壤铅的方法价格昂贵，通常提供基于网格的污染模型，对采样点之间的铅浓度具有很大的不确定性。SBIR第一阶段项目旨在开发一种草坪草生物传感器，提供低成本、高分辨率的底层土壤中铅浓度的植被图，从而帮助识别危险和补救活动。该项目利用了最近在芥菜中发现的与B花青素调控基因相关联的金属反应启动子元件。转化启动子-报告基因的拟南芥植株在铅离子存在的情况下构建过表达的花青素，产生可见的(紫色)金属积累指示物。在第一阶段，这一反应的敏感性和特异性将在拟南芥中进行单独测试，并与目前用于增加植物铅吸收以进行植物修复的瞬时植物萃取剂(如柠檬酸)结合使用。第一阶段的活动还将包括用启动子-报告构建转化草坪草。在第二阶段，工程草坪草的性能将在铅污染的场地进行表征和演示。该项目的成功完成将为一种创新的、低成本的土壤铅生物传感技术奠定基础，该技术将使房主、房地产开发商和环境专业人员能够检测和监测广泛存在的环境污染物对健康的危害。事实证明，这项技术不仅在检测污染方面非常有用，而且在监测使用草坪草的植物修复活动的有效性、监测生物可利用铅的水平以及检测来自风媒粉尘或径流的清洁场地的再污染方面也是非常有用的。此外，草坪草作为土壤铅生物传感器的示范有望刺激低成本生物传感技术的发展，以应对其他环境健康危害。

DESCRIPTION (provided by applicant): Soil lead presents a major environmental health hazard, particularly to children. Current methods of detecting soil lead are expensive and typically provide grid-based models of contamination with significant uncertainties about lead concentrations between sampling points. This SBIR Phase I project seeks to develop a turf grass biosensor that provides a low-cost, high-resolution vegetative map of lead concentrations in the underlying soil, thereby assisting hazard identification and remediation activities. The project takes advantage of a recently-discovered metal responsive promoter element in Brassica juncea linked to the B anthocyanin regulatory gene. Arabidopsis thaliana plants transformed with the promoter-reporter construct overexpress anthocyanin in the presence of lead ions, creating a visible (purple) indicator of metal accumulation. In Phase I, the sensitivity and specificity of this response will be tested in Arabidopsis, alone and in combination with transient phytoextraction agents such as citric acid that are currently used to increase lead uptake in plants for phytoremediation. Phase I activities will also include transforming turf grass with the promoter-reporter construct. In Phase II, the performance of the engineered turf grass will be characterized and demonstrated at a lead-contaminated site. Successful completion of the project should lay the foundation for an innovative, low-cost biosensing technique for soil lead that will allow homeowners, real estate developers and environmental professionals to detect and monitor health hazards of a widespread environmental contaminant. The technique should prove extremely useful not only in detecting contamination, but also in monitoring the effectiveness of phytoremediation activities using turf grass, monitoring levels of bioavailable lead, and detecting recontamination at cleaned sites from windborne dust or runoff. In addition, demonstration of turf grass as a biosensor for soil lead is expected to stimulate development of low-cost biosensing techniques for other environmental health hazards.