Barley Yellow Striate Mosaic Virus in the Salivary Glands of its Planthopper Vector Laodelphax striatellus Fallen

Abstract

SUMMARY The salivary glands of planthoppers, Laodelphax striatellus, transmitting barley yellow striate mosaic virus (BYSMV), cryptogram */*:*/*:U/U:S,I/Au, were sectioned and examined in the electron microscope. BYSMV was detected in the cytoplasm but not in the nuclei or other organelles of infected cells which did not show structural changes. The BYSMV virions, 300 to 320 nm long and about 40 nm wide, were frequently arranged in parallel aggregates bound by a membrane. Long flexuous tubules of variable length, 18 to 20 nm wide were found in close association with BYSMV. The tubules were typically found in bundles surrounded by a membrane which also contained virus particles in different stages of organization. The virion of BYSMV is believed to consist of two coaxial helices, the inner derived from the tubules and the outer being formed between the inner helix and the outer envelope of the virus. A hypothesis is advanced for the morphogenesis of BYSMV in insect tissue which differs from that occurring in plants.