ABSTRACT
Genetic engineering technology is an efcient way to improve organisms, overcoming the barrier of reproduction isolation across unrelated species. Genetically modied organisms (GMOs) refer to organisms in which the genetic compositions have been changed in a way that does not happen naturally (European Commission 2001). To date, many kinds of GMOs including microorganisms, animals, and plants have been created and applied, particularly, genetically modied (GM) crops have been widely planted. In 2012, globally about 170.3 million hectares of GM crops were planted in 28 countries, and a total of 59 countries authorized 319 GM events as food or feed as well as the release into the environment (James 2013). A total of 2497 regulatory approvals have been ofcially issued, among which 1129 are relative to food use (James 2013).
