Canto Tomas, Palukaitis Peter
Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland, United Kingdom.
J Virol. 2002 Dec;76(24):12908-16. doi: 10.1128/jvi.76.24.12908-12916.2002.
The N gene conditions for resistance to Tobacco mosaic virus (TMV) but only below 28 degrees C. However, a TMV-based vector expressing green fluorescent protein (TMV-GFP) showed only limited movement at 33 degrees C in tobacco plants harboring the N gene and other genes cointrogressed from Nicotiana glutinosa. TMV-GFP moved efficiently in tobacco plants that either lacked these genes or that contained the N gene but were transgenic for RNA1 of Cucumber mosaic virus. These findings identified novel temperature-independent resistance to the movement of TMV-GFP which could be neutralized by a different viral transgene. Using the N gene and nahG gene-transgenic tobacco, we show that this novel resistance is manifested specifically by the N gene itself and operates via a pathway independent of salicylic acid.
N基因决定了对烟草花叶病毒（TMV）的抗性，但仅在28摄氏度以下。然而，一种表达绿色荧光蛋白的基于TMV的载体（TMV-GFP）在携带N基因以及从粘毛烟草共导入的其他基因的烟草植株中，于33摄氏度时移动受限。TMV-GFP在缺乏这些基因的烟草植株中，或者在含有N基因但对黄瓜花叶病毒RNA1进行了转基因操作的烟草植株中能高效移动。这些发现确定了对TMV-GFP移动的新型温度非依赖性抗性，这种抗性可被另一种病毒转基因中和。利用N基因和转nahG基因的烟草，我们表明这种新型抗性是由N基因本身特异性表现出来的，并且通过一条独立于水杨酸的途径发挥作用。
