近二年报道,在TMV、PVX、PEBV和CMV等病毒中,利用病毒编码的复制酶(亚基)基因或相关cDNA片段转化烟草,工程植株获得绝对或极高的病毒抗性。大量研究认为:马铃薯Y病毒组的核内含体大分子量蛋白(NIb)是依赖于RNA的RNA复制酶(或核心亚基),NIb与上述病毒的复制酶有广泛的同源保守区。因此,NIb基因的克隆,不但在植物抗病基因工程方面,而且在马铃薯 In the past two years, it has been reported that tobacco plants are transformed with virally-encoded replicase (subunit) genes or related cDNA fragments in viruses such as TMV, PVX, PEBV and CMV and the engineered plants obtain absolute or very high virus resistance. Numerous studies suggest that NIb, an RNA-dependent RNA replicase (or core subunit), is present in the potato Y virus group. NIb shares a broad range of homologous conserved regions with the above-mentioned viral replicase. Therefore, the cloning of NIb genes, not only in plant disease resistance gene engineering, but also in potato