转hrfAXoo基因水稻对白叶枯病的抗性

将来自水稻白叶枯病菌(Xanthomonas oryzae pv．oryzae)编码harpinxoo的hrfAxoo基因连接到双元载体pBI121上,构建成含hrfAxoo基因的植物表达质粒pBMH9。以粳稻R109成熟胚诱导愈伤组织,由根癌农杆菌EHA105介导,将含有hrfAxoo基因的重组质粒pBMH9转化水稻愈伤组织。用G-418抗生素做抗性筛选,产生抗性愈伤组织的频率为85％,转化植株的再生频率为53％。根据hrfAxoo基因两端序列和pBMH9中外源片断的旁侧序列设计2对引物,通过PCR扩增验证转化水稻中的靶基因序列。对部分转基因水稻进行RT—PCR和Northern blot分析,结果显示hrfAxoo基因在转基因水稻中能正常表达。抗病性鉴定结果表明,转基因水稻在,ID、T1和T2代对水稻白叶枯病有较好的抗性;在转基因系中水稻白叶枯病菌的生长明显受到抑制。因此,本研究获得对水稻白叶枯病抗性提高的转基因水稻。

Transformation of rice with hrfAXoo gene and resistance of transgenic plants to bacterial leaf blight

The gene hrfA Xoo derived from Xanthomonas oryzae pv. oryzae encoding harpin Xoo has been constructed into transgenic vector pBI121(called pBMH9)and transferred into Agrobacterium EHA105.Mature embryos of rice cultivar R109 precultured were infected and transformed by Agrobacterium tumefaciens strain EHA105/pBMH9.The resistant calli were transferred into the differentiation medium and plants were regenerated.The transformation frequency reached 85% measured as numbers of Geneticin(G-418)-resistant calli produced and 53% measured as numbers of transgenic plants regenerated,respectively.RT-PCR and Northern blot analysis of transgenic plants confirmed that hrfA Xoo gene had been expressed in transgenic rice plants at transcription level.Disease bioassays of T0,T1 and T2 transgenic plants indicated that the resistance of transgenic plants to bacterial leaf blight was enhanced.