Aphids are insect vectors that have piercing-sucking mouthparts supporting diversified patterns of virus-vector interactions. Aphids primarily retain circulative viruses in the midgut/hindgut, whereas noncirculative viruses tend to be retained in the stylet. Most viruses, and many proteins from animals, have carbohydrate or carbohydrate-binding sites. Lectins vary in their specificity, of which some are able to bind to viral glycoproteins. To assess the potential competition between lectins and viral particles in virus transmission by aphids, this study examined how feeding plant lectins to aphids affects the transmission efficiency of viruses. Sitobion avenae (F, 1794) (Homoptera: Aphididae) aphids fed with Pisum sativum lectin (PSL) transmitted Barley yellow dwarf virus with significantly lower efficiency (four-fold ratio). Pea enation mosaic virus was significantly reduced in Acyrthosiphon pisum Harris (Homoptera: Aphididae) aphids fed with the lectin Concanavalin A. In comparison, the transmission of Potato virus Y was significantly reduced when Myzus persicae Sultzer (Homoptera: Aphididae) aphids were fed with PSL. Thus, lectin could be used as a blocking agent of plant viruses, facilitating an alternative approach for crop protection.

Keywords: aphid; glycoprotein; lectin; receptor; virus transmission.