Recently we isolated the Tm-22 gene of tomato, which confers resistance to tobamoviruses. The gene encodes a polypeptide that belongs to the group of the CC-NBS-LRR resistance proteins. In this paper, we show that the tomato Tm-22 gene can be functionally transferred into tobacco. After introduction of the gene either under the control of the tomato Tm-22 promoter and polyadenylation signal or the CaMV 35S promoter and the NOS-polyadenylation signal, tobacco SR1 transgenic plants become resistant against infection with ToMV. Virus-specificity of the transgenic resistance remains as in the donor species tomato: of the six ToMV-isolates used, only the Tm-22 breaking strain was able to infect transgenic tobacco-lines. In tomato the matching avirulence gene of the Tm-22 resistance is the Movement Protein (MP) of the virus. Transgenic tobacco plants expressing the MP were crossed to plants harbouring an expressing Tm-22 gene. This resulted in non-viable progeny seeds, implying that as in tomato also in tobacco the Tm-22 matching avirulence protein of ToMV is the MP and its sole presence is enough to trigger the defense response.
- Virus specificity
- Plant disease resistance gene
- Tomato mosaic virus
- Lycopersicon esculentum
- Nicotiana tabacum