FORMATION OF MULTIMERS OF CUCUMBER MOSAIC-VIRUS SATELLITE RNA

Double-stranded RNA multimers of cucumber mosaic virus (CMV) satellite RNA were detected in CMV-infected plants. RT-PCR showed that plus-sen se and minus-sense monomers and plus-sense multimers of satellite RNA were present. Multimeric minus-sense RNA was not present except in the form of multimeric dsRNA. Sequence analysis of 52 cloned junction reg ions in head-to-tail repeats of unit-length satellite RNA indicated th at about 35% of the junction sequences were precise fusions of monomer units, 56% lacked sequence of the 5' component, and 10% lacked sequen ce of both 3' and 5' components. No junction contained additional nucl eotides. Deletions at the junction regions may have accumulated during CMV multiplication in inoculated plants. These data suggest that repl icase is not released from the template during synthesis of multimeric molecules of satellite RNA.