The Transfer of Foreign Genes and Its Expression Products in Genetically Modified Crops
转基因植物中外源基因及其表达产物转移的途径

It has been very important to understand thoroughly potential ecological risk of genetically modified crops (GMCs) with the recent increase of commercial use of GMCs. The likelihood of transgenes dispersal from GMCs to the related wild species, the tolerance of insect to insect\|resistant GMCs and the potential impacts of GMCs on biodiversity had been extensively investigated. This article summarized several possible characteristics of the transfer of foreign genes and their expression products in GMCs: (i) Gene flow from GMCs via pollen dispersal. The distance of pollen flow is determined not only by the biological properties of pollen of different species, but also by natural surroundings; (ii) Spontaneous hybridizations between GMCs and other closely related wild species, which may result in creating super\|weeds; (iii) The fate and consequences of foreign genes and proteins of GMCs in soil micro\|ecosystem. It has been demonstrated that foreign genes or proteins of GMCs can survive for a long time in soils. It has also been shown that Bt plants can secrete Bt toxin from root throughout the entire growth stages, and these toxins can be released from residual materials of GMCs and can be deposited into soils after harvesting. It was suggested that Bt plants may impact the environment, for example, producing toxins to non\|target microorganisms in soils and forcing the evolution of toxin\|resistant target species; (iv) Gene flow via food chains that may influence the biodiversity of nature, such as the effect of GM Bt crops on predators or parasites. Finally, the identification methods of the existence of transgenes and their expressing products were also briefly discussed.