Two distinct mechanisms regulate luteovirus transmission efficiency and specificity at the aphid salivary gland

Barley yellow dwarf luteovirus (BYDV) particles are transmitted by aphids in a species-specific manner. Transmission to plants requires that the virus particles be transported across the basal lamina and plasmalemma of the accessory salivary gland (ASG). To characterize the role of the ASG basal lamina in regulating BYDV transmission, five aphid species were microinjected with purified New York isolates BYDV-PAV or-RPV. Both viruses associated specifically only with the ASG basal lamina. The ability of virions to penetrate the basal lamina was separate from the ability to penetrate the plasma-lemma. When the salivary glands of vector, Sitobion avenae, or non-vector, Rhopalosiphum maidis, aphids were incubated in vitro with New York isolate BYDV-MAV, virions only attached to the ASG basal lamina of S. avenae. When anionic and cationi