外源基因在转基因植物中的失活

Inactivation of Foreign Genes in Transgenic Plant

进行植物基因工程研究首先需要获得外源基因稳定表达的转基因植株。近年来，有大量文献报道，转基因植株中外源基因的失活是一种普遍发生的现象。引起外源基因失活的原因是多方面的，外源基因失活在ＤＮＡ修饰水平，基因转录水平和转录后调节水平均可能发生。深入地了解外源基因失活的原因以及寻找出有效的防范对策，对顺利开展植物基因工程育种是非常必要的。

The goal of plant genetic engineering is to obtain transgenic plants that foreign gene can be normally expressed and faithfully inheritted in a predictable manner. However, in recent years, it were widely reported that transgene inactivation was often found in transgenic plants. There are many reasons that cause transgene inactivation,and inactivation can emerge at different gene expression stage, such as DNA modification level ,transcriptional level and post-transcriptional level. It is necessary for gene engineering breeding to reveal mechanims of foreign gene inactivation and take strategies to overcome transgene inactivation as well.