Serological relationships between tobacco necrosis virus-inducible cucumber peroxidase and corresponding peroxidase isoenzymes in other Cucurbitaceae.

Pathogenesis-related peroxidases (PRXs), found in leaves of different cucurbits infected with tobacco necrosis virus (TNV), were compared serologically using a highly specific rabbit antiserum raised against PRX purified from TNV-infected cotyledons of Cucumis sativus L., cv. Laura. After native polyacrylamide gel electrophoresis (PAGE) of intercellular washing fluid extracts from a large number of species of this family, immunoblot analysis revealed the presence of cross-reacting protein bands in all species tested. Despite the serological relatedness, the analysis also revealed that the antiserum recognized only fast-moving PRX isoenzymes localized in the apoplast space.