Replication of Cucumber Mosaic Virus Satellite RNA from Negative-sense Transcripts Produced Either in Vitro or in Transgenic Plants

Abstract

Both positive [(+)] and negative [(-)]sense versions of two satellite RNA (satRNA) genes from cucumber mosaic virus (CMV), the necrogenic I17N and the nonnecrogenic R, have been introduced into the genome of tobacco plants. On infection with satRNA-free CMV, satRNA was amplified in plants expressing each of the four genes. All four genes confer protection against CMV infection. However, co-inoculation of plants with viral RNA and CMV satRNA transcripts synthesized in vitro showed that (-) sense transcripts were less active than the corresponding (+) sense transcripts. This is the first report that (-) sense CMV satRNA transcripts can serve as a template for satRNA replication.

Formation of multimers of cucumber mosaic virus satellite RNA.

“…In addition, Tousch et al (1994) have shown that CMV satellite RNA can be replicated in plants from plus-and minus-sense in vitro transcripts of strict monomer satellite RNA flanked by extensive 5h and 3h sequence when coinoculated with satellite-free CMV RNA. In our results in vivo transcripts of dimer satellite RNA were also biologically active to generate monomer satellite RNA.…”

Structure and Functional Relationships of Satellite RNAs of Cucumber Mosaic Virus

“…1987(MASUTA et a!. [n one study, where extra sequences were present at both termini 01' (+) satellite RNA transcripts, either poor or no satellite RNA infection was observed (K LJRATH and P ALLJKAITIS 1987), while in another study, extra sequences at both termini of the (+ ) satellite RNA transeripts had no apparent effect on infectivity (TOUSCH et a!. [n one study, where extra sequences were present at both termini 01' (+) satellite RNA transcripts, either poor or no satellite RNA infection was observed (K LJRATH and P ALLJKAITIS 1987), while in another study, extra sequences at both termini of the (+ ) satellite RNA transeripts had no apparent effect on infectivity (TOUSCH et a!.…”

“…However, in those plants that were infected, the levels of ss and ds satellite RNA were similar to what was observed in plants inoculated with (+) satellite RNA transeripts (TOUSCH et a!. [n addition, in transgenie plants expressing (-) satellite RNAs containing extra sequences at both termini, CMV was able to replicate the satellite RNA, but the level of accumulated (+) satellite RNA was much lower (TOUSCH et a!. [n addition, in transgenie plants expressing (-) satellite RNAs containing extra sequences at both termini, CMV was able to replicate the satellite RNA, but the level of accumulated (+) satellite RNA was much lower (TOUSCH et a!.…”

Replication of the genomic RNA of a positive-strand RNA animal virus from negative-sense transcripts.

“…Paradoxically, however, most attempts to initiate replication with input negative-strand RNA, either in cellfree replication systems or in cells expressing the appropriate RNA replicase, have been unsuccessful. Only in rare cases has infectivity been recovered from the negative-strand complement of a positive-strand RNA viral genome (2,3).…”