title: Potato virus X movement in Nicotiana benthamiana: new details revealed by chimeric coat protein variants.
abstract: Potato virus X coat protein is necessary for both cell-to-cell and phloem transfer, but it has not been clarified definitively whether it is needed in both movement phases solely as a component of the assembled particles or also of differently structured ribonucleoprotein complexes. To clarify this issue, we studied the infection progression of a mutant carrying an N-terminal deletion of the coat protein, which was used to construct chimeric virus particles displaying peptides selectively affecting phloem transfer or cell-to-cell movement. Nicotiana benthamiana plants inoculated with expression vectors encoding the wild-type, mutant and chimeric viral genomes were examined by microscopy techniques. These experiments showed that coat protein-peptide fusions promoting cell-to-cell transfer only were not competent for virion assembly, whereas long-distance movement was possible only for coat proteins compatible with virus particle formation. Moreover, the ability of the assembled PVX to enter and persist into developing xylem elements was revealed here for the first time.
authors.affiliation: Unità Tecnica Biologia delle Radiazioni e Salute dell'Uomo, Laboratorio di Biotecnologie, ENEA CR Casaccia, Via Anguillarese 301, 00123, Rome, Italy.
authors.forename: Camilla
authors.initials: C
authors.lastname: Betti
authors.forename: Chiara
authors.initials: C
authors.lastname: Lico
authors.forename: Dario
authors.initials: D
authors.lastname: Maffi
authors.forename: Simone
authors.initials: S
authors.lastname: D'Angeli
authors.forename: Maria Maddalena
authors.initials: MM
authors.lastname: Altamura
authors.forename: Eugenio
authors.initials: E
authors.lastname: Benvenuto
authors.forename: Franco
authors.initials: F
authors.lastname: Faoro
authors.forename: Selene
authors.initials: S
authors.lastname: Baschieri
mesh_terms: D000595:Amino Acid Sequence; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism*; D005070:Evans Blue / Q000378:metabolism; D008969:Molecular Sequence Data; D009068:Movement; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism*; D018515:Plant Leaves / Q000166:cytology / Q000648:ultrastructure / Q000821:virology; D017863:Potexvirus / Q000502:physiology* / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism*; D014026:Nicotiana / Q000166:cytology / Q000648:ultrastructure / Q000821:virology*
chemical_list: D036022:Capsid Proteins; D050505:Mutant Proteins; D011994:Recombinant Proteins; C058750:coat protein, Potato virus X; D005070:Evans Blue