Transgenic tomato plants expressing the tomato yellow leaf curl virus capsid protein are resistant to the virus.

The tomato yellow leaf curl virus (TYLCV) gene that encodes the capsid protein (V1) was placed under transcriptional control of the cauliflower mosaic virus 35S promoter and cloned into an Agrobacterium Ti-derived plasmid and used to transform plants from an interspecific tomato hybrid, Lycopersicon esculentum X L. pennellii (F1), sensitive to the TYLCV disease. When transgenic F1 plants, expressing the V1 gene, were inoculated with TYLCV using whiteflies fed on TYLCV-infected plants, they responded either as untransformed tomato or showed expression of delayed disease symptoms and recovery from the disease with increasingly more resistance upon repeated inoculation. Transformed plants that were as sensitive to inoculation as untransformed controls expressed the V1 gene at the RNA level only. All the transformed plants that recovered from disease expressed the TYLCV capsid protein.