Distribution of cylindrical inclusion, amorphous inclusion and capsid proteins of watermelon mosaic virus 2 in systemically infected pumpkin leaves

Monoclonal antibodies (MAbs) were prepared against he cylindrical inclusion protein (CIP), amorphous inclusion protein (AIP) and capsid protein (CP) of watermelon mosaic virus 2 (WMV2). Using the MAbs, CIP, AIP and CP were detected, roughly quantitatively, in WMV2-infected pumpkin leaves howing various symptoms by using electroblot-ELISA. From symptomless leaves and most dark green areas in the mosaic pattern o protein or small amounts of the three proteins were detected, but from most yellow areas in the mosaic almost equal amounts of each protein were detected in abundance. Leaves showing mild vein-yellowing and vein-clearing (respectively, the first and second leaves of the plants tested) contained AIP and CP in large amounts, but little CIP. On the other hand, expanding leaves contained CIP and AIP in large quantities, butCP in traces only. Therefore the distributions of CIP, AIP and CP in pumpkin plants were very uneven, but correlated with symptoms. In addition, the ratio f the concentrations of CIP, AIP and CP varied from tissue to tissue