Association of Tobacco Rattle Virus with Mitochondria

As part of a study of the way in which tobacco rattle viruses multiply, we have examined the intracellular distribution of the cam isolate (Harrison & Woods, 1966) by means of electron microscopy of thin sections of leaves. The micrographs show a remarkable association between virus particles and mitochondria. Nothing comparable seems to have been reported with other viruses.

Tip leaves, about 2 cm. long, were taken from plants of Nicotiana clevelandii Gray 5 days after their lower leaves were inoculated with the cam isolate. Narrow strips of leaf blade were fixed in 5% (v/v) glutaraldehyde, post-fixed in 0.1% OsO4, stained during dehydration for 16 hr in a saturated solution of uranyl acetate in 70% (v/v) acetone, and embedded in methyl methacrylate + styrene (6:1, v/v). Sections, mostly about 600 Å thick, were cut with a Huxley ultramicrotome, using a glass knife.