Electrophoretic mobility of the capsid protein of the Plum pox virus strain PPV-Rec indicates its partial phosphorylation.

A double-band SDS-PAGE profile was found reproducible for capsid protein (CP) of Plum pox virus (PPV) isolates belonging to the strain PPV-Rec. The double-band was also present in the virus population multiplied in various plants. A single-lesion passage in a hypersensitive host Chenopodium foetidum showed that its presence was not a result of a mixed infection.

Two biologically distinct isolates of Zucchini yellow mosaic virus lack seed transmissibility in cucumber.

The seed transmission of the Zucchini yellow mosaic virus (ZYMV) was studied in cucumber using two isolates unrelated in their biological characteristics. Although the virus could be readily detected in mature seeds harvested from infected cucumbers, the seedlings obtained from infected germinated seeds tested negative for ZYMV using both ELISA and RT-PCR assays. No evidence was obtained for transmission of two ZYMV isolates through seeds.

Influence of extracellular and cytoplasmic domains of M2 ion channel of influenza a virus on its activity.

Co-expression of M2 protein of Influenza A virus (IAV) with pH-sensitive hemagglutinin (HA) reduces the conversion of HA to its low pH conformation during transport to the cell surface. Mutational analysis of extracellular domain of M2 protein showed that single aa substitution W 15A did not influence the ion channel activity of M2 protein. Replacement of first 24 aa of M2 protein with first 18 aa of NB protein of Influenza B virus in chimera BAA resulted in the loss of ion channel activity.

pH modulating activity of ion channels of influenza A, B, and C viruses.

The BM2 and NB proteins of Influenza B virus (the B virus) and the CM2 protein of Influenza C virus (the C virus) are structural homologs of the M2 protein of Influenza A virus (the A virus). It was shown recently that CM2 in vitro forms a voltage-activated ion channel permeable to chloride ion (Hongo et al., Arch.

Plum Pox Virus Mixed Infection Detected on Apricot in Pakistan.

Sharka, caused by Plum pox virus (PPV), is the most detrimental viral disease of stone fruit trees. First reported from Bulgaria in 1917, the virus is now widespread in Europe, the Mediterranean Basin, and Asia Minor and is sporadically present in North and South America. On the basis of molecular and serological properties, six PPV subgroups are recognized, from which PPV-D, PPV-M, and PPV-Rec are the most common (1,2).