The subject invention concerns materials and methods for providing genetically-engineered resistance in plants to tomato yellow leaf curl geminivirus using a truncated version of the replication associated protein (Rep) gene of TYLCV. Virus-resistant plants produced according to the present invention have horticulturally acceptable phenotypic traits. Methods of the invention comprise transforming a plant with a polynucleotide wherein when the polynucleotide is expressed in the plant, the transformed plant exhibits resistance to plant viral infections. An exemplified embodiment utilizes a polynucleotide comprising a truncated Rep gene derived from a Florida isolate of TYLCV-Is. The methods of the invention can be used to provide resistance to TYLCV infection in plants such as tomato and tobacco. The present invention also concerns transformed and transgenic plants and plant tissue that express a polynucleotide comprising a truncated Rep gene of TYLCV.