The characteristics of tm - 22 expression presented in transgenic tobacco : 1 ) . virus specificity in either homozygote or heterozygote ; 2 ) tm - 22 gene integrated in tobacco genomic dna with single copy and in inheritance and segregation to progenies on the mendel role ; 3 ) . transgenic line with tm - 22 promoter ( ptm47 ) showed infected symptoms with cell death distinguished to one with 35s promoter ( ptm49 ) after inoculation with tomv - 2a 其次,通过氨基酸序列和结构的比较,确定tm - 2 ~ 2基因的编码蛋白与tomv病毒在抗病反应中相互识别的特异氨基酸及其功能;然后,应用重组dna技术,互换tm - 2 ~ 2基因和tm - 2基因的对应结构域,构建嵌合基因,获得嵌合蛋白表达的转化体,验证tm - 2 ~ 2编码蛋白中变异氨基酸的作用。