van den Boogaart T, Wen F, Davies J W, Lomonossoff G P
John Innes Centre, Norwich, UK.
Mol Plant Microbe Interact. 2001 Feb;14(2):196-203. doi: 10.1094/MPMI.2001.14.2.196.
Virus resistance in Nicotiana benthamiana plants containing a translatable Pea early browning virus (PEBV) 54K sequence from the 201K replicase gene has been reported previously. Resistant plants contain multiple transgene copies divided between two loci. Analysis of a genetic series containing the two loci in separate homozygous or heterozygous condition suggest that only one of the loci is necessary to induce the resistance. The resistance observed in R2 and R3 generations of lines containing both transgene loci in homozygous condition became less consistent in R4 and R5 generations. This inversely correlated with steady-state transgene transcript levels of the segregating populations. The use of recombinant Potato virus X vectors carrying PEBV 54K sequences showed that the resistance is based upon posttranscriptional gene silencing, is non-strand specific, and recognizes 3' located sequences within the PEBV 54K sequence.
先前已有报道称,本氏烟草植株中含有来自201K复制酶基因的可翻译的豌豆早褐病毒(PEBV)54K序列,从而具有病毒抗性。抗性植株含有多个转基因拷贝,分布在两个位点。对包含处于单独纯合或杂合状态的两个位点的遗传系列进行分析表明,诱导抗性只需其中一个位点。在纯合状态下包含两个转基因位点的品系的R2和R3代中观察到的抗性,在R4和R5代中变得不那么一致。这与分离群体的稳态转基因转录水平呈负相关。使用携带PEBV 54K序列的重组马铃薯X病毒载体表明,这种抗性基于转录后基因沉默,不具有链特异性,并识别PEBV 54K序列内位于3'端的序列。