Satellite Nature of the Viroid-like RNA-2 of Solanum Nodiflorum Mottle Virus and the Ability of Other Plant Viruses to Support the Replication of Viroid-like RNA Molecules

Publisher Website
Google Scholar
Abstract
The stock culture of solanum nodiflorum mottle virus (SNMV) was freed from RNA-2 by passage through single lesions induced in inoculated leaves of Nicotiana debneyi by dilute inocula of partially purified SNMV RNA-1. This isolate (S1) was indistinguishable serologically and in symptomatology from the stock culture of SNMV. Using a sensitive bioassay for detecting RNA-2, no SNMV RNA-2 was found in RNA from particles of the S1 isolate purified after three successive passages in Nicotiana clevelandii. Addition of SNMV RNA-2 (which is not infective alone) had little or no effect on the infectivity of S1 RNA but restored the RNA content of particles to that found in the stock culture (RNA-1 and RNA-2). However, S1 did not support the replication of the RNA-2 from lucerne transient streak virus (LTSV). The possible interaction of the RNA-2 species from LTSV and SNMV with the genomes of other plant viruses was tested by mixing the RNA-2 species with nucleic acid from 11 other viruses. The survival of RNA-2 activity on inoculated leaves for up to 15 days complicated the interpretation of the results of these tests but a small amount of LTSV RNA-2 and SNMV RNA-2 was obtained only from particles of turnip rosette virus purified from plants inoculated with the relevant RNA mixtures. These and other data suggest that these RNA-2 molecules with physicochemical properties similar to viroids found in particles of some sobemoviruses are satellite RNA species whose multiplication is assisted by some, but not all, of the viruses in this group.