Suzuki M, Masuta C, Takanami Y, Kuwata S
Life Science Research Laboratory, Japan Tobacco Inc., Yokohama, Japan.
FEBS Lett. 1996 Jan 22;379(1):26-30. doi: 10.1016/0014-5793(95)01477-2.
CMV RNAs 1 and 2 are considered to constitute the viral replicon. Tobacco plants were transformed with either RNA1 or RNA2 to produce plant lines V1 and V2, respectively. Plants homozygous for each of the RNAs were generated and crossed to produce V1V2 (V2V1) lines that expressed both RNA1 and RNA2. An RNase protection assay indicated that RNA1 and RNA2 multiplied in V1V2 (V2V1) plants. Surprisingly, V1V2 (V2V1) plants, unlike their parent lines, showed a remarkably high level of resistance to CMV; this resistance was more effective against RNA inoculation than against virion inoculation. Experiments using protoplasts showed that the resistance was expressed at the single cell level. All the data together suggested that the observed resistance does not fit the criteria for either 'RNA-mediated' or 'replicase-mediated' resistance.
巨细胞病毒RNA1和RNA2被认为构成病毒复制子。分别用RNA1或RNA2转化烟草植株，以产生植物株系V1和V2。获得了每种RNA的纯合植株，并进行杂交以产生同时表达RNA1和RNA2的V1V2（V2V1）株系。核糖核酸酶保护试验表明，RNA1和RNA2在V1V2（V2V1）植株中增殖。令人惊讶的是，V1V2（V2V1）植株与其亲本株系不同，对巨细胞病毒表现出极高水平的抗性；这种抗性对RNA接种比对病毒粒子接种更有效。使用原生质体的实验表明，这种抗性在单细胞水平上表达。所有数据共同表明，观察到的抗性不符合“RNA介导”或“复制酶介导”抗性的标准。
