转双价基因抗虫杨抑制美国白蛾的作用机理研究

Investigation on Inhibition Mechanism of Transgenic Poplar with Binary Insectresistant Genes to Hyphantria cunea

为明确双价基因chitinase-BmkIT对鳞翅目害虫的作用机制,以美国白蛾为供试虫源,用转双价基因(烟草天蛾几丁质酶基因和东亚钳蝎昆虫特异性神经毒素基因)杨树叶片饲喂其幼虫,至3龄时,采用石蜡切片法,对美国白蛾幼虫中肠结构进行观察,并对其头部乙酰胆碱酯酶活性进行测定。结果表明,取食转基因杨树叶片的美国白蛾幼虫中肠结构不完整,中肠细胞出现排列不整齐、脱落等现象;而取食非转化杨树叶片的美国白蛾幼虫中肠结构完整,中肠细胞排列整齐紧密。转基因杨树叶片还显著抑制了美国白蛾幼虫头部乙酰胆碱酯酶的活性(p<0.05)。取食转chitinase-BmkIT基因杨树叶片抑制了幼虫的生长,并使部分幼虫身体溃烂。该双价基因可作为防治美国白蛾的基因源。

To reveal the mechanism of binary genes chitinase-BmkIT on Lepidopterous insect, larvae of Hyphantria cunea were fed with the leaves of transgenic poplar harboring chitinase gene and BmklT gene. The 3rd instar larvae midgut structures were observed and the acetylcholinesterase activities in their heads were measured. The results showed that midgut structures of larvae fed with transgenic leaves were incomplete and cells were disordered and detached versus those fed with transformed control. At the same time, transgenic leaves inhibited acetylcholinesterase activities in larva head significantly （p 〈 0.05）. Larvae fed with transgenic leaves were inhibited in growth and some larvae were ulcerated. Study confirms that the insect-resistant gene combination could be used as one of the alien gene sources to resist Hyphantria cunea.