Center for Fisheries, Aquaculture, and Aquatic Sciences and Department of Zoology, Southern Illinois University Carbondale, IL 62901, USA.
Chemosphere. 2015 Aug;132:94-100. doi: 10.1016/j.chemosphere.2015.03.005. Epub 2015 Mar 28.
Genetically engineered crops expressing insecticidal crystalline proteins derived from Bacillus thuringiensis (Bt), were commercialized almost two decades ago as a means to manage agricultural pests. The Bt proteins are highly specific and only lethal upon ingestion, limiting the scope of toxicity to target insects. However, concern of exposure to non-target organisms and negative public perceptions regarding Bt crops has caused controversy surrounding their use. The objective of this research was to monitor the fate and transport of a Bt protein, Cry1Ab, in a large-scale agricultural field containing maize expressing the Cry1Ab protein and a non-Bt near isoline, and in aquatic microcosms. The highest environmental concentrations of the Cry1Ab protein were found in runoff water and sediment, up to 130ngL(-1) and 143ngg(-1) dry weight, respectively, with the Cry1Ab protein detected in both Bt and non-Bt maize fields. As surface runoff and residual crop debris can transport Bt proteins to waterways adjacent to agricultural fields, a series of laboratory experiments were conducted to determine the potential fate of the Cry1Ab protein under different conditions. The results showed that sediment type and temperature can influence the degradation of the Cry1Ab protein in an aquatic system and that the Cry1Ab protein can persist for up to two months. Although Cry1Ab protein concentrations measured in the field soil indicate little exposure to terrestrial organisms, the consistent input of Bt-contaminated runoff and crop debris into agricultural waterways is relevant to understanding potential consequences to aquatic species.
近二十年前，人们商业化种植了表达苏云金芽孢杆菌（Bt）杀虫晶体蛋白的基因工程作物，以此作为防治农业害虫的手段。Bt 蛋白具有高度特异性，只有在摄入时才具有致命性，从而将毒性范围限制在目标昆虫上。然而，人们对接触非目标生物的担忧以及对 Bt 作物的负面公众看法引起了围绕其使用的争议。本研究的目的是监测在含有表达 Cry1Ab 蛋白的玉米和非 Bt 近等基因系的大型农业田间以及水生微宇宙中，Bt 蛋白 Cry1Ab 的命运和迁移。Cry1Ab 蛋白的最高环境浓度出现在径流水和沉积物中，分别高达 130ngL(-1)和 143ngg(-1)干重，Bt 和非 Bt 玉米田中均检测到 Cry1Ab 蛋白。由于地表径流和残留作物残渣可以将 Bt 蛋白运输到靠近农田的水道，因此进行了一系列实验室实验，以确定 Cry1Ab 蛋白在不同条件下的潜在命运。结果表明，沉积物类型和温度会影响水生系统中 Cry1Ab 蛋白的降解，并且 Cry1Ab 蛋白可以持续存在长达两个月。尽管田间土壤中测量的 Cry1Ab 蛋白浓度表明对陆地生物的暴露很少，但 Bt 污染径流和作物残渣不断输入农业水道，与了解对水生物种的潜在影响有关。
