title: In vivo generated Citrus exocortis viroid progeny variants display a range of phenotypes with altered levels of replication, systemic accumulation and pathogenicity.
abstract: Citrus exocortis viroid (CEVd) exists as populations of heterogeneous variants in infected hosts. In vivo generated CEVd progeny variants (CEVd-PVs) populations from citrus protoplasts, seedlings and mature plants, following inoculation with transcripts of a single CEVd cDNA-clone (wild-type, WT), were studied. The CEVd-PVs population in protoplasts was heterogeneous and became progressively more homogeneous in seedlings and mature plants. The infectivity and pathogenicity of selected CEVd-PVs was evaluated in citrus and herbaceous experimental hosts. The CEVd-PVs U30C, G128A and U182C were not infectious; G50A and 108U+ were infectious but reverted back to WT and 62A+, U129A and U278A were infectious, genetically stable and more severe than WT. The 62A+ and U278A and U129A accumulated at higher levels than WT in protoplasts and seedlings respectively. The effect of specific mutations on the predicted secondary structure of the CEVd-PVs' RNA coupled with the infectivity and replication studies suggested complex structure-to-function relationships for CEVd.
authors.affiliation: Department of Plant Pathology and Microbiology, University of California, Riverside CA 92521, USA.
authors.forename: Subhas
authors.initials: S
authors.lastname: Hajeri
authors.forename: Chandrika
authors.initials: C
authors.lastname: Ramadugu
authors.forename: Keremane
authors.initials: K
authors.lastname: Manjunath
authors.forename: James
authors.initials: J
authors.lastname: Ng
authors.forename: Richard
authors.initials: R
authors.lastname: Lee
authors.forename: Georgios
authors.initials: G
authors.lastname: Vidalakis
mesh_terms: D002957:Citrus / Q000821:virology*; D008969:Molecular Sequence Data; D009154:Mutation; D009690:Nucleic Acid Conformation; D010935:Plant Diseases / Q000821:virology*; D011110:Polymorphism, Genetic; D012367:RNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D017422:Sequence Analysis, DNA; D014772:Viroids / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D014779:Virus Replication
chemical_list: D012367:RNA, Viral