【摘要】 利用植物基因工程培育抗除草剂的农作物品种是扩大现有除草剂的使用范围和安全使用除草剂，形成经济、有效、对环境安全、与现代化农艺相配套的除草技术的关键。基因工程改良农作物对除草剂的抗性的主要途径有二：一是利用点突变修饰除草剂对植物作用靶标的水平和敏感性，或诱导靶酶或靶标蛋白质过量生产，使作物吸收除草剂后仍能进行正常的代谢作用；二是引入降解除草剂的酶和酶系统，在除草剂发生作用前将其降解或解毒。现已在几种重要的农作物中转入抗除草剂基因，获得２０多种稳定的抗除草剂转基因工程植株，其中已有部分进入田间试验和生产应用。更多还原

【Abstract】 Herbicide treatments in crop fields can result in economic weed control andprovide cost-effective increases in agricultural productivity.Although herbicides more readilyavailable and currently in use combine a high degree of effectiveness with favourableproduction costs; non-toxicity and rapid biodegradation;they often lack selectivity; thuslimiting their use in preemergence application.Genetic engineering for herbicide tolerance incrops is a new way of conferring selectivity and enhancing crop safety and production.Atleast two different strategies have beed employed in genetic engineering for herbicideresistance. The most straightforward strategy is to identify an enzyme or other gene productthat detoxifies or inactivates the herbicide.The second strategy is to identify a gene thatencodes a different form of the target enzyme;which is less sensitive to the herbicide;and/orintroduce a gene that overproduces the target enzyme in transformed plants.More than 20transgenic crops with herbicide tolerance have been field-tested successfully and should becommercially a7ailable within the next few years. The potential danger from herbicideresistant transgenic plants should be considered for further strengthening plant geneticengmeermg.更多还原