RNA intermediates in potato spindle tuber viroid replication

Abstract
Two double-stranded RNA intermediates of viroid replication were isolated from potato spindle tuber viroid (PSTV)-infected tomato tissue and characterized by polyacrylamide gel electrophoresis and DNA-RNA hybridization techniques. These replicative intermediates contain monomeric circular or linear PSTV strands complexed with a multimeric complementary RNA strand. Synchronous synthesis of single-stranded PSTV is accompanied by a simultaneous marked increase in double-stranded PSTV RNA; thus, in vivo precursors of the characterized double-stranded PSTV RNA seem to be involved in PSTV replication. A rolling circle model for viroid replication on a circular PSTV template can accommodate the double-stranded PSTV RNA species characterized.