我国抗虫转基因杨树生态安全性研究进展

转基因树木与农作物相比, 人们更关注其长时间种植可能导致转基因扩散到周围野生近缘种。由于生长周期长, 转基因树木会增加转基因不稳定性, 对非靶标生物的影响, 靶标害虫对转基因植物产生抗性, 增加树木入侵性(杂草化), 以及由于基因漂移或基因逃逸对环境产生的负面影响或新的环境风险。过去十几年, 针对我国抗食叶害虫的两个商业化转Bt基因欧洲黑杨(Populus nigra)和转双抗虫基因741杨[P. alba× (P. davidiana + P. simonii) × P. tomentosa], 已开展了有关生态安全性方面的多项研究。本文围绕抗虫转基因树木生态安全性研究进展进行了综述。抗虫转基因杨树对节肢动物种群和群落结构产生了一定影响, 使昆虫的多样性提高, 但对土壤微生物区系未见明显影响。转基因欧洲黑杨通过花粉和种子发生的基因漂移几率很低。转基因杨树通过内生菌发生的水平转移可能会对环境造成的潜在危险也进行了评价。文章最后指出对抗虫转基因杨树农林复合生态系统开展生物安全研究的必要性。

Advances in biosafety studies on transgenic insect-resistant poplars in China

More concerns have been focused on transgenic trees than transgenic food crops because of their longevity and the likelihood that transgene might spread to related species of wild trees grown nearby. Detailed, the long life span of trees could increase the likelihood of transgene instability, affect diversity of non-target organisms, improve resistance to insecticidal proteins, increase invasiveness of the tree itself (weediness), and arouse negative environmental consequences or new environmental risks resulted from gene flow or gene escape. The transgenic black poplar Populus nigra carrying Bt gene and hybrid white poplar clone 741[Populus alba× (P. davidiana + P. simonii) × P. tomentosa] carring fusion genes, which are resistant to leaf insects, have been commercial release in China since 2002. In this review, we provide a brief overview of biosafety assessment researches on transgenic insect-resistant poplar varieties during the last decades. Arthropod population and community structure have changed within the transgenic poplar plantations, and the diversity of the insect community has increased. But there are no significant changes for soil microbial communities. Gene flow monitoring in the transgenic black poplar plantation showed that the probability of gene escape is very low via pollen and seeds. The potential environment risk was also evaluated based on the experiments of horizontal gene transfer from transgenic poplars through endophytic bacteria. We pointed out the necessity of the biosafety assessments concerning the transgenic poplars when intercropping with food crops.