The biosafety of genetically engineered plants has been of concernment in society and science in recent years. The issue of 35S promoter of CaMV has been contentious because of its wide use in plant genetic engineering. The debate on the safety and potential risks of the 35S promoter will be discussed here. Some of concerns are expressed about the dissemination of antibiotic-resistance genes and vector backbone sequences. Various methods and strategies are currently being developed for the marker gene excision and elimination of vector backbone sequences from transgenic plants. In this review, the CRE/ lox system which could get rid of the marker geens and vector backbone sequences will be discussed in detail. Advances in the research of the safety assessment of genetically modified plants using the CRE/ lox system will also be described.

转基因植物中外源非目的基因片段的生物安全研究进展
董志峰^1,2* 马荣才³ 彭于发⁴  管华诗¹

（1.  青岛海洋大学，青岛266003；2.  中国生物工程开发中心，北京!100081；
3. 北京农业生物技术研究中心，北京100089; 4.  中国农业科学院植物保护研究所，北京100094）
关键词： 生物安全；35S启动子；标记基因；载体骨架序列；cre/lox

农药是一类用于防治作物病虫草害、保障粮食生产与安全的化学物质。传统农药剂型载药粒子粒径粗大, 有效利用率低, 用量大, 对生态环境造成严重危害。农药纳米剂型可以提高载药系统的分散性、稳定性及生物活性, 是克服传统剂型功能缺陷、提高农药有效利用率、减少环境污染的重要科学途径。研究纳米农药粒子在植物体内的吸收与转运行为, 对于理解纳米农药与植物的互作方式, 揭示其在植物体内的吸收作用机制及生物累积效应, 以及明确其生物安全性具有重要意义。该文从纳米农药在植物体内的吸收转运影响因素、机制、分析方法及其生物安全性4个方面进行综述, 阐明了无机和有机纳米农药在植物体内的吸收转运模式及研究手段, 并展望了其应用前景, 以期为纳米农药的设计、构建及合理安全使用提供理论与技术支撑。