title: A stable 463 nucleotide variant of citrus exocortis viroid produced by terminal repeats.
abstract: An unusual variant of citrus exocortis viroid (CEV) was detected when an inoculum source from Gynura aurantiaca D.C. was used to infect a hybrid tomato (Lycopersicon esculentum Mill. x L. peruvianum). The 92 nucleotide larger variant, CEV D-92, which displayed the characteristic circular and linear viroid structural forms, contained two repeated sequences spanning the V and T2 domains. A dramatic moderation of symptom expression in Gynura accompanied the incorporation of these repeated sequences. A comparison of the sequence and structure of CEV D-92 with coconut cadang-cadang viroid revealed similarities in the regions generating the naturally occurring terminal repeats suggesting a possible preferred site for RNA recombination between viroids.
authors.affiliation: Department of Plant Pathology, University of California, Riverside 92521.
authors.forename: J S
authors.initials: JS
authors.lastname: Semancik
authors.forename: J A
authors.initials: JA
authors.lastname: Szychowski
authors.forename: A G
authors.initials: AG
authors.lastname: Rakowski
authors.forename: R H
authors.initials: RH
authors.lastname: Symons
mesh_terms: D001483:Base Sequence; D014644:Genetic Variation / Q000235:genetics*; D008969:Molecular Sequence Data; D010944:Plants / Q000382:microbiology; D012367:RNA, Viral / Q000302:isolation & purification; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014772:Viroids / Q000235:genetics* / Q000254:growth & development
chemical_list: D012367:RNA, Viral