Movement of a Barley Stripe Mosaic Virus Chimera with a Tobacco Mosaic Virus Movement Protein

Abstract

The tobacco mosaic virus (TMV) 30K movement protein (MP) gene was inserted into a full-length cDNA clone of barley stripe mosaic virus (BSMV) RNAβ replacing the triple gene block (TGB). The resulting recombinant ND-MPT genome, consisting of infectious wt transcripts of BSMV RNAs α and γ, together with the hybrid RNAβ transcript, was inoculated onto test plants to study the functional compatibility between the BSMV TGB-adapted genetic system and the tobamovirus transport gene. ND-MPT infected the inoculated leaves ofNicotiana benthamianaandChenopodium amaranticolor,which are common hosts for the parental viruses; the size, growth rate, and morphology of local lesions onC. amaranticolorwere influenced by the foreign MP gene. However, the hybrid virus failed to infect barley,N. tabacum(var. Samsun), andN. clevelandii,the selective hosts. Thus, the TMV MP was able to functionally substitute for the BSMV TGB-coded MPs, i.e., the 30K MP functioned independently of any other BSMV sequences. However, the TMV MP gene promoted the cell-to-cell movement in a host-dependent manner.