Morphology and intracellular localization of bacilliform virus particles associated with the clover enation disease

Abstract

In ultrathin sections of tumorous tissues of white clover plants artificially infected by grafting with the clover enation virus nuclei and nucleoli were very much enlarged. Such nuclei contained massive amounts of tubular particles in crystalline array. In spaces between the nuclear membrane lamellae such particles had an additional coat and usually occurred in irregular accumulations. These bacilliform particles measured about 200 • 80 m~z. This virus was not found in normal tissues.Two other viruses with elongated particles of 475 and 665 m~ were also observed in non-neoplastic tissues. They were easily detected in negatively stained chop preparations, rapidly transmitted by sap, and considered to be mere contaminants.Enation virus diseases are heterogeneous in epidemiology and etiology. Several have recently been found associated with dense accumulations of big spherical or polyhedral virus particles. The virus detected here closely resembles several bacilliform viruses described in recent years. These viruses are quite different in symptomatology and epidemiology.

A Rhabdovirus of Cynara in Italy

“…This possibility is supported by several findings: 1. nuclei of viruscontaining cells were apparently unchanged and did not differ substantially from those of healthy controls. By converse, it is known that rhabdoviruses with nuclear maturation often elicit recognizable nuclear alterations (KITAJIMA and COSTA 1966, RUBIO-HUERTOS and Bos 1969, MARTELLI 1969, CHEN and SHIKATA 1971, CHRISTIE et al 1974, Russo and MARTELLI 1975; 2. nucleocapsids or whole virions were not found in the nucleoplasm, nor CyRV particles were ever seen budding at the inner lamella of the nuclear envelope; 3. perinuclear accumulations of virus particles, so often encountered with rhabdoviruses maturing at the nuclear membrane, were absent; 4. in the rare instances when immature virions were found associated with the nuclear envelope, their coat was continuous with the outer rather than with the inner lamella of the envelope (fig.4), i.e. the particles were external to the caryoplasm; 5. structures having aspect and size comparable to that of internal components of virus particles were visualized in the cytoplasm.…”

Bacilliform Particles within Infected Cells of Trifolium incarnatum

“…As a continuation of a survey of legume viruses in Spain (RUBIO-HUERTOS et al 1967) we studied different samples of clover (Trifolium incamatum) by inoculation of test plants and electron microscopy; some of the samples were infected by two viruses, a strain of bean yellow mosaic virus (BYMV) which induced in the host cells intranuclear and intracytoplasmic crystalline inclusion bodies and another virus with bacilliform and bullet-shaped particles. In this paper we study the ultrastructure of the bacilliform virus particles, their distribution m the host cell and some aspects of virions assembly.…”