title: Studies on the role of the minor capsid protein in transport of Beet western yellows virus through Myzus persicae.
abstract: Beet western yellows virus (BWYV), family Luteoviridae, is an icosahedral plant virus which is strictly transmitted by aphids in a persistent and circulative manner. Virions cross two cellular barriers in the aphid by receptor-based mechanisms involving endocytosis and exocytosis. Particles are first transported across intestinal cells into the haemolymph and then across accessory salivary gland cells for delivery to the plant via saliva. We identified the midgut part of the digestive tract as the site of intestinal passage by BWYV virions. To analyse the role in transmission of the minor capsid component, the readthrough (RT) protein, the fate of a BWYV RT-deficient non-transmissible mutant was followed by transmission electron microscopy in the vector Myzus persicae. This mutant was observed in the gut lumen but was never found inside midgut cells. However, virion aggregates were detected in the basal lamina of midgut cells when BWYV antiserum was microinjected into the haemolymph. The presence of virions in the haemolymph was confirmed by a sensitive molecular technique for detecting viral RNA. Thus, transport of the mutant virions through intestinal cells occurred but at a low frequency. Even when microinjected into the haemolymph, the RT protein mutant was never detected near or in the accessory salivary gland cells. We conclude that the RT protein is not strictly required for the transport of virus particles through midgut cells, but is necessary for the maintenance of virions in the haemolymph and their passage through accessory salivary gland cells.
authors.affiliation: INRA, 28 rue de Herrlisheim, 68021 Colmar Cedex, France1.
authors.forename: C
authors.initials: C
authors.lastname: Reinbold
authors.affiliation: Department of Plant Pathology, Pennsylvania State University, University Park, PA 16802, USA2.
authors.forename: F E
authors.initials: FE
authors.lastname: Gildow
authors.affiliation: INRA, 28 rue de Herrlisheim, 68021 Colmar Cedex, France1.
authors.forename: E
authors.initials: E
authors.lastname: Herrbach
authors.affiliation: IBMP, 12 rue du Général Zimmer, 67084 Strasbourg Cedex, France3.
authors.forename: V
authors.initials: V
authors.lastname: Ziegler-Graff
authors.affiliation: Instituto Biológico-CEIB, PO Box 70, 13001-970 Campinas, SP, Brazil4.
authors.forename: M C
authors.initials: MC
authors.lastname: Gonçalves
authors.affiliation: De Ruiter Seeds, PO Box 1050, 2660 BB Bergschenhoek, Netherlands5.
authors.forename: J F J M
authors.initials: JFJM
authors.lastname: van den Heuvel
authors.affiliation: INRA, 28 rue de Herrlisheim, 68021 Colmar Cedex, France1.
authors.forename: V
authors.initials: V
authors.lastname: Brault
mesh_terms: D000818:Animals; D001042:Aphids / Q000821:virology*; D015152:Blotting, Northern; D002213:Capsid / Q000235:genetics / Q000378:metabolism*; D004199:Disease Vectors; D006458:Hemolymph; D007422:Intestines / Q000821:virology; D017793:Luteovirus / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D012367:RNA, Viral / Q000032:analysis; D012469:Salivary Glands / Q000821:virology
chemical_list: D012367:RNA, Viral