Kiyoshi Yora

Infection of cowpea mesophyll protoplasts with cucumber mosaic virus

Abstract Mesophyll protoplasts isolated from cowpea primary leaves were inoculated with cucumber mosaic virus according to the same procedures as those developed for inoculating them with cowpea mosaic virus. Virus multiplication in the inoculated protoplasts was demonstrated by fluorescent-antibody staining, by electron microscopy of ultrathin sections, and by infectivity assay. Seventy to ninety-five percent of the inoculated protoplasts were infected. Poly( l -ornithine) was not essential for CMV infection, but it had a stimulating effect. No sign of necrosis suggesting cell death was observed until 36 hr after inoculation.

Intracellular appearance of Penicillium chrysogenum virus.

Abstract An electron microscopic study of intracellular Penicillium chrysogenum virus showed virus particles with a dense core distributed as individuals or aggregates in cytoplasm and/or in vacuoles of mycelial cells. In cytoplasm the virus particles were often near, but not in, the nucleus. Electron-dense regions of granular appearance enclosed more complete virus particles in some cells. Lipid bodies, vacuoles, and membranous structures were often prominent in infected cells. Sometimes cylindrical arrays of virus particles occurred in vacuoles and also in degenerated cells. Aberrations consisting of various degrees of degeneration or disappearance of cytoplasm and cellular organelles were often observed in aged cells with large quantities of virus. The virus particles sometimes released fibrous material forming networks from their core region.