Studies on the agent of artichoke mottled crinkle: IV. Intracellular localization of the virus

Abstract

Ultrathin sections were prepared from leaves of artichoke seedlings artificially infected with purified preparations of artichoke mottled crinkle virus (AMCV). When examined with the electron microscope, the cytoplasm and vacuoles of leaf hair cells, upper and lower epidermis, and mesophyll cells contained a very large number of rounded or hexagonal bodies about 26 mμ across, believed to be virus particles. These occur irregularly scattered or in crystalline aggregates. No such particles are present in healthy artichoke tissues. Cell organelles appear variously damaged. The virus distribution and localization within the cell is illustrated and discussed. Vacuolar localization of AMCV does not seem to be accidental. Bubblelike vesicles, containing virus and protruding from the cytoplasm into the vacuole and into gaps between the plasma membrane and the cell wall, are indicated as sites of a possible mechanism for virus disposal beyond the membrane system of the cell.