Development of a “deconstructed” vector based on the genome of grapevine virus A

Abstract

The development of new vectors based on plant viruses creates more efficient vectors driving high expression levels of heterologous proteins. Currently, deconstructed vectors are more suitable for the expression of target genes. We attempted to develop a deconstructed vector based on the genome of grapevine virus A (GVA) by replacing the coat protein gene of GVA to the coat protein gene (aCP) of ACLSV (apple chlorotic leaf spot virus). This is the first work on creation of deconstructed vector based on GVA genome. The heterologous gene was placed under the control of the CP subgenomic promoter of GVA and fused with ORF5. The 2A self-cleaving sequence was inserted between the target protein and the protein encoded by ORF5 to enable the expression of separate proteins. The transient expression of coat protein of ACLSV from this vector was assessed in both transgenic plants carrying the CP of GVA and in non-transgenic plants. The level of aCP expression in transgenic plants was higher than the expression level in non-transgenic plants. Transgenic plants were developed in this study to increase target protein yield, because GVA cannot move between cells in its non-encapsidated form. The developed vector based on the grapevine virus A genome can be used in transient expression of different heterologous proteins utilizing magnifection method or via co-agroinfiltration with native genome of GVA.