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

• Published in: Journal of general virology Vol. 78; no. 3; pp. 495 - 503
• Main Authors: Peiffer, ML, Gildow, FE, Gray, SM
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01-03-1997
• Subjects: Animals; Aphids - metabolism; barley yellow dwarf virus; Basement Membrane; Ferritins - metabolism; Gold Colloid; Luteovirus - metabolism; Rhopalosiphum maidis; Salivary Glands - metabolism; Salivary Glands - virology; Sitobion avenae
• ISSN: 0022-1317; 1465-2099
• DOI: 10.1099/0022-1317-78-3-495

ML Peiffer, FE Gildow and SM Gray
Department of Plant Pathology, Pennsylvania State University, University Park 16802, USA.
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 plasmalemma. 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 cationic ferritin were microinjected
into aphids, only cationic ferritin aggregated on the surface of the ASG
basal lamina and at openings of plasmalemma invaginations into the
cytoplasm, suggesting that these sites had a net negative charge. In vitro
studies of anionic and cationic gold penetration of ASG basal laminae
indicated a macromolecular size exclusion limit of approximately 20 nm that
depended on charge. Anionic gold particles did not accumulate in the basal
lamina as densely as the 25 nm BYDV particles, suggesting that the virus
particles have a greater affinity for the ASG basal lamina. These results
indicate that both the ASG basal lamina and plasmalemma contain specific
components independently involved in the recognition and transmission of
luteoviruses.