Tobacco streak virus (TSV: genus Ilarvirus) and Tobacco mosaic Virus (TMV: genus Tobamovirus) are taxonomically distinct plant viruses. In addition, the two genera differ in morphological structure and require movement protein (MP) for systemic movement in the host vasculature. Here, we show that the TSV MP gene is capable of facilitating the vascular movement of a Tobacco mosaic virus. Substitution of the TMV MP with the TSV MP gene permits movement of the resulting chimeric virus to non-inoculated leaves. TMV lacking a MP gene or contains truncated TSV MP gene do not move systemically. This report introduces the molecular characterization of TSV MP and describes its complementation of systemic movement function of TMV MP gene.
