转Bt基因作物对土壤动物的影响

Effects of Transgenic Bt Crops on Soil Animals

转Bt基因作物是将Bt基因加以修饰后导入作物中,使作物获得抗虫性的这类农作物的总称。转Bt基因作物商品化种植取得显著经济效益的同时,其释放的Bt毒蛋白对土壤动物的影响也日趋受到关注。Bt基因表达的外源蛋白能通过根系分泌物、作物残茬、花粉传播等多条途径进入土壤,并与土壤中的活性粒子相结合,结合后的蛋白更难被土壤生物和酶降解,从而在土壤中富集,对土壤动物产生潜在风险。综述了几类转Bt基因作物种植对几种主要土壤动物蚯蚓、线虫、跳虫等影响的最新研究进展,以期为转Bt基因作物生态风险评价提供参考。

Transgenic Bt crops are commercial crops transformed with insecticidal genes which are derived from Bacillus thuringiensis, and they can produce a kind of insecticidal toxin to kill pests. With the wide application of commercialized transgenic Bt crops in large area, increasing attention has also been paid to the effect of released Bt toxin protein expressed in transgenic Bt crops on soil animals. Bt toxin protein may enterinto soil ecosystem by several ways, such as root exudates, crop residues remaining in the field after harvest,and pollen spread during the flowering season. After entering into soil, Bt toxin protein may combine with theactive particles in the soil. And the combined proteins are less likely to be degraded by soil organisms and soilenzyme. This combination leads to retention and enrichment of Bt toxin proteins and then may produce potential risk to non-target animals in the soil. The author systematically reviewed the latest research progress of the effects of Bt toxin proteins on soil animals, such as earthworm, nematode, etc, to provide reference for ecological risk assessments of transgenic Bt crops on soil ecosystem.