ABSTRACT
Pea enation mosaic virus (PEMV) was first described by Osborn, and its properties were reviewed by Shepherd, Hull, Peters, and Francki and co-workers. PEMV aphid-transmissible strains act as helper virus for non-aphid-transmissible strains and bean yellow vein-banding virus. Crystalline inclusions of PEMV particles have been detected in cytoplasm of pea. In thin-section studies of the aphid Acyrthosiphon pisum, PEMV particle aggregation was noted in the lumen of the gut and in the cytoplasm of fat bodies. PEMV aphid-transmissible strains act as helper virus for non-aphid-transmissible strains and bean yellow vein-banding virus. Shikata and Maramorosch described masses of PEMV particles in pea nuclei. In such nuclei the nucleoli disappear, chromatin aggregates at the periphery of nuclei, and eventually nuclear membranes rupture, liberating virus into the cytoplasm. In the light microscope, inclusions consisting of PEMV particles stain green in the O-G combination and red in Azure A.
