Beet necrotic yellow vein virus (BNYVV), the causal agent of Rhizomania, is the model species of Benyvirus genus together with Beet soil-borne mosaic virus (BSBMV). Both viruses are vectored by Polymyxa betae. By the use of full-length clones from all genomic RNAs, molecular interactions between plant and Benyviruses are being investigated exploiting biological, epidemiological and molecular similarities/divergences between BNYVV and BSBMV. Results. cDNA copies from all BSBMV RNAs and BNYVV (type P) RNA-1 and 2 have been successfully synthesized and infectivity of the in vitro transcribed RNAs evaluated through rub-inoculation onto Chenopodium quinoa plant leaves. BSBMV RNA2 and BNYVV (type P) RNA-1 cDNA clones are not infectious and still need to be modified. A molecular characterization of chimeric strain consisting of B-type RNA-1 and P-type RNA-2 in comparison with B-type RNA-1 and RNA-2 will be reported. Difference on the expression level of proteins encoded by BNYVV P/B-type RNA-3 (p25), RNA-4 (p31) and RNA-5 (p26) have been evidenced.