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很昂贵，而且通常提供基于网格的污染模型，采样点之间的铅浓度存在很大的不确定性。该SBIR一期项目旨在开发一种草坪草生物传感器，提供低成本、高分辨率的土壤铅浓度植物图，从而协助危害识别和补救活动。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的金属响应启动子元件。用启动子报告结构转化的拟南芥植物在铅离子存在下过度表达花青素，产生一个可见的（紫色）金属积累指标。在第一阶段，将在拟南芥中测试这种反应的敏感性和特异性，单独或与瞬态植物提取剂（如柠檬酸）联合使用，目前用于增加植物对铅的吸收以进行植物修复。第一阶段的活动还将包括用发起人-报告者结构改造草坪。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土壤铅的创新、低成本生物传感技术奠定基础，使房主、房地产开发商和环境专业人员能够发现和监测广泛存在的环境污染物对健康的危害。这项技术不仅在检测污染方面非常有用，而且在监测利用草坪的植物修复活动的有效性，监测生物可利用铅的水平，以及检测清洁场地的风载尘埃或径流的再污染方面也非常有用。此外，草坪草作为土壤铅的生物传感器的示范预计将刺激对其他环境健康危害的低成本生物传感技术的发展。

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.