Functional analysis of the cassava vein mosaic virus promoter and its usage for cassava genetic engineering

Cassava vein mosaic virus (CsVMV) is a plant pararetrovirus infecting cassava plants in Brazil. The promoter which directs the synthesis of the terminally redundant genome length viral ribonucleic acid (RNA), was isolated and used to express heterologous genes in transgenic plants. A deletion analysis of the upstream region of the promoter was carried out in order to study its functional structure. Effects of the deletions were examined in tobacco plants using the vida reporter gene. Additional data were obtained by protoplast transfection experiments and in vitro deoxyribonucleic acid (DNA) binding assays. The constitutive pattern of the promoter expression is due to the promoter sequence of organo-specific cis elements. The specifity of the virus for cassava plants and the constitutive as well as the molecular function of its promoter, make it a good alternative to the 35S. (Résumé d'auteur