NICOTIANA BENTHAMIANA PLANTS EXPRESSING BEET NECROTIC YELLOW VEIN VIRUS (BNYVV) COAT PROTEIN-SPECIFIC SCFV ARE PARTIALLY PROTECTED AGAINST THE ESTABLISHMENT OF THE VIRUS IN THE EARLY STAGES OF INFECTION AND ITS PATHOGENIC EFFECTS IN THE LATE STAGES OF INFECTION

Transgenic plants of Nicotiana benthamiana expressing single chain ant ibody fragments (scFv) specific for the coat protein of beet necrotic yellow vein virus (BNYVV) and non-expressing control plants were inocu lated with BNYVV mechanically and by means of the vector Polymyxa beta e. The scFv were presumably expressed in the endoplasmic reticulum (ER ). The average time needed for infections to become detectable was lon ger in the scFv-expressing plants than in the non-expressing control p lants. In addition, the scFv-expressing plants were partially protecte d against the pathogenic effects exerted by the virus on N. benthamian a plants in the late stages of infection.