摘要
兔防御素ＮＰ－ｌ是α-防御素的一种，含３３个氨基酸残基。最初从兔子的多形核嗜中性细胞中分离出来。它对革兰氏阴性菌、革兰氏阳性菌、分枝杆菌、真菌、被膜病毒以及ＨＩＶ病毒都有不同程度的抑制作用。兔防御素ＮＰ－１所带阳离子较多，可抗不具代谢活性的靶细胞。实验中将兔防御素ＮＰ－１基因构建到植物表达载体中，通过根瘤农杆菌介导转入番茄，得到了转基因番茄植株。对转基因番茄植株进行了 ＰＣＲ． Ｓｏｕｔｈｅｒｎ杂交、 Ｎｏｒｔｈｅｒｎ点杂交及体外抑菌检测，证实了兔防御素ＮＰ－ｌ基因已经转入番茄中，并得到了正常的表达，抗病实验表明转基因番茄对番茄青枯病具有抗性，为番茄的抗病育种工作奠定了基础。
Rabbit defensin NP-1 is one kind of α-defensins. It is composed of 33 amino acids. It was firstly extracted from polymorphonnuclear neutrophile of rabbits. It displayed resistance to bacteria, fungi and virus, especially high resistance to bacteria. In our experiments NH-1 gene was constructed into a plant expression vector. Eight transgenic plants containing the rabbit defensin gene (NP-1) were obtained through agrobacterium-mediated transformation. The transgenic plants were analysized by PCR, Southern hybridization, Northern dot blot hybridization and in vitro microbicidical activity against E. colt and Fusarium oxysporum. The results showed that NP-1 gene was transformed into the tomato, and the transgene displayed physiological-level expression. The transgenic tomato also showed resistance to pathogen Fusarium oxysporum in vivo. Our experiments paved a way for pathogen resistance breeding of tomato.
