In vivo accumulation of a turnip crinkle virus defective interfering RNA is affected by alterations in size and sequence.
Turnip crinkle virus is one of several single-stranded RNA plant viruses associated with defective interfering (DI) RNAs. A complete cDNA copy of a 344-base DI RNA (DI RNA G) was cloned downstream from a T7 RNA polymerase promoter. Transcripts synthesized in vitro were infectious when inoculated with helper virus on turnip plants. Studies of the infectivity of DI transcripts containing deletions, insertions, and single-base changes suggest that (i) in general, only the 5' two-thirds of the molecule can tolerate mutations; (ii) between 52 and 67 bases of terminal 5' sequence are required for infectivity; (iii) nucleotides in positions 68 to 138 are not specifically involved in RNA infectivity; (iv) DI RNA G molecules smaller than 327 bases are not amplified efficiently in plants.
Li
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Department of Plant Pathology, University of Massachusetts, Amherst 01003.
Simon
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D001483:Base Sequence; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004252:DNA Mutational Analysis; D003673:Defective Viruses / Q000235:genetics*; D008969:Molecular Sequence Data; D010942:Plant Viruses / Q000235:genetics* / Q000254:growth & development; D012367:RNA, Viral / Q000378:metabolism*; D015183:Restriction Mapping; D014675:Vegetables; D014762:Viral Interference; D014779:Virus Replication
D012367:RNA, Viral