title: Actin Cytoskeleton and Golgi Involvement in Barley stripe mosaic virus Movement and Cell Wall Localization of Triple Gene Block Proteins.
abstract: Barley stripe mosaic virus (BSMV) induces massive actin filament thickening at the infection front of infected Nicotiana benthamiana leaves. To determine the mechanisms leading to actin remodeling, fluorescent protein fusions of the BSMV triple gene block (TGB) proteins were coexpressed in cells with the actin marker DsRed: Talin. TGB ectopic expression experiments revealed that TGB3 is a major elicitor of filament thickening, that TGB2 resulted in formation of intermediate DsRed:Talin filaments, and that TGB1 alone had no obvious effects on actin filament structure. Latrunculin B (LatB) treatments retarded BSMV cell-to-cell movement, disrupted actin filament organization, and dramatically decreased the proportion of paired TGB3 foci appearing at the cell wall (CW). BSMV infection of transgenic plants tagged with GFP-KDEL exhibited membrane proliferation and vesicle formation that were especially evident around the nucleus. Similar membrane proliferation occurred in plants expressing TGB2 and/or TGB3, and DsRed: Talin fluorescence in these plants colocalized with the ER vesicles. TGB3 also associated with the Golgi apparatus and overlapped with cortical vesicles appearing at the cell periphery. Brefeldin A treatments disrupted Golgi and also altered vesicles at the CW, but failed to interfere with TGB CW localization. Our results indicate that actin cytoskeleton interactions are important in BSMV cell-to-cell movement and for CW localization of TGB3.
authors.affiliation: Department of Applied Biology, Chungnam National University, Daejeon 305-764, Korea.
authors.forename: Hyoun-Sub
authors.initials: HS
authors.lastname: Lim
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA.
authors.forename: Mi Yeon
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Green Bio Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon 305-333, Korea.
authors.forename: Jae Sun
authors.initials: JS
authors.lastname: Moon
authors.affiliation: National Institute of Crop Science, Suwon, Rural Development Administration, 441-707, Korea.
authors.forename: Jung-Kyung
authors.initials: JK
authors.lastname: Moon
authors.affiliation: Department of Applied Biology, Chungnam National University, Daejeon 305-764, Korea.
authors.forename: Yong-Man
authors.initials: YM
authors.lastname: Yu
authors.affiliation: National Institute of Horticultural & Herbal Science, Rural Development Administration, Suwon 441-440, Korea.
authors.forename: In Sook
authors.initials: IS
authors.lastname: Cho
authors.affiliation: School of Biotechnology, Yeungnam University, Gyeongsan, Korea.
authors.forename: Hanhong
authors.initials: H
authors.lastname: Bae
authors.affiliation: Virology Department, Wageningen University, 6709 PD Wageningen, The Netherlands.
authors.forename: Matt
authors.initials: M
authors.lastname: deBoer
authors.affiliation: Department of Agricultural Biology, Chonbuk National University, Jeonju 561-756, Korea.
authors.forename: Hojong
authors.initials: H
authors.lastname: Ju
authors.affiliation: USDA-ARS, US National Arboretum, Floral and Nursery Plants Research Unit, Beltsville, MD 20705 USA.
authors.forename: John
authors.initials: J
authors.lastname: Hammond
authors.affiliation: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720 USA.
authors.forename: Andrew O
authors.initials: AO
authors.lastname: Jackson
keywords: Barley stripe mosaic virus; Hordeivirus; Latrunculin B; Membrane proliferation; Triple gene block