title: A mutation in the Lettuce infectious yellows virus minor coat protein disrupts whitefly transmission but not in planta systemic movement.
abstract: The Lettuce infectious yellows virus (LIYV) RNA 2 mutant p1-5b was previously isolated from Bemisia tabaci-transmitted virus maintained in Chenopodium murale plants. p1-5b RNA 2 contains a single-nucleotide deletion in the minor coat protein (CPm) open reading frame (ORF) that is predicted to result in a frameshift and premature termination of the protein. Using the recently developed agroinoculation system for LIYV, we tested RNA 2 containing the p1-5b CPm mutant genotype (agro-pR6-5b) in Nicotiana benthamiana plants. We showed that plant infection triggered by agro-pR6-5b spread systemically and resulted in the formation of virions similar to those produced in p1-5b-inoculated protoplasts. However, virions derived from these mutant CPm genotypes were not transmitted by whiteflies, even though virion concentrations were above the typical transmission thresholds. In contrast, and as demonstrated for the first time, an engineered restoration mutant (agro-pR6-5bM1) was capable of both systemic movement in plants and whitefly transmission. These results provide strong molecular evidence that the full-length LIYV-encoded CPm is dispensable for systemic plant movement but is required for whitefly transmission.
authors.affiliation: Plant Pathology Department, University of California, Davis, Davis, California 956161, USA.
authors.forename: Lucy R
authors.initials: LR
authors.lastname: Stewart
authors.forename: Vicente
authors.initials: V
authors.lastname: Medina
authors.forename: Tongyan
authors.initials: T
authors.lastname: Tian
authors.forename: Massimo
authors.initials: M
authors.lastname: Turina
authors.forename: Bryce W
authors.initials: BW
authors.lastname: Falk
authors.forename: James C K
authors.initials: JC
authors.lastname: Ng
mesh_terms: D000818:Animals; D001483:Base Sequence; D036022:Capsid Proteins / Q000235:genetics*; D029383:Crinivirus / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D006430:Hemiptera / Q000821:virology*; D015151:Immunoblotting; D007303:Insect Vectors / Q000821:virology*; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009154:Mutation / Q000235:genetics; D010935:Plant Diseases / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014026:Nicotiana / Q000821:virology*; D014771:Virion / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D036022:Capsid Proteins; D017931:DNA Primers; C088125:coat protein, Lettuce infectious yellows virus