Targeted expression of single-chain antibody inhibits the accumulation of Beet necrotic yellow vein virus in Nicotiana benthamiana

ABSTRACTRhizomania is one of the most damaging sugar beet diseases and is caused by Beet necrotic yellow vein virus (BNYVV). In order to interfere with viral propagation, the expression of recombinant antibody strategy was employed. The coding sequence of a single-chain variable fragment (scFv) specific to the main BNYVV coat protein, P21, was targeted to the cytosol, apoplast or outer membrane of mitochondrion of Nicotiana benthamiana plants. Also, an endoplasmic reticulum retention signal peptide, KDEL, was added at the C-terminal of the scFv protein which presumably stabilizes it in cytoplasm. Although the accumulation levels of scFv could not be correlated to the levels of the inhibition of viral accumulation, the titer of the virus in all groups of transgenic plants was significantly lower than the wild type ones when grown in BNYVV-infested soil. No significant differences were found in the number of resistant plants targeting P21-scFv in either putative subcellular locations.