EXPRESSION OF THE TOMATO LEAF CURL GEMINIVIRUS C4 GENE PRODUCES VIRUS-LIKE SYMPTOMS IN TRANSGENIC PLANTS

Transgenic tobacco and tomato plants expressing the C4 gene from tomat o leaf curl geminivirus (TLCV), under the control of the cauliflower m osaic virus 35S promoter, developed virus-disease-like phenotypes, Pla nts transformed with a frame-shift version of the C4 gene construct ap peared normal but produced levels of transcript similar to those of pl ants expressing the C4 gene. Thus, the abnormal plant phenotypes resul t from translation of the C4 gene, These results support the hypothesi s that the C4 open reading frame of TLCV encodes a protein involved in the development of disease symptoms during viral infection.