title: The p33 auxiliary replicase protein of Cucumber necrosis virus targets peroxisomes and infection induces de novo peroxisome formation from the endoplasmic reticulum.
abstract: Tombusviruses replicate on pre-existing organelles such as peroxisomes or mitochondria, the membranes of which become extensively reorganized into multivesicular bodies (MVBs) during the infection process. Cucumber necrosis virus (CNV) has previously been shown to replicate in association with peroxisomes in yeast. We show that CNV induces MVBs from peroxisomes in infected plants and that GFP-tagged p33 auxiliary replicase protein colocalizes with YFP(SKL), a peroxisomal marker. Most remarkably, the ER of CNV infected Nicotiana benthamiana 16C plants undergoes a dramatic reorganization producing numerous new peroxisome-like structures that associate with CNV p33, thus likely serving as a new site for viral RNA replication. We also show that plants agroinfiltrated with p33 develop CNV-like necrotic symptoms which are associated with increased levels of peroxide. Since peroxisomes are a site for peroxide catabolism, and peroxide is known to induce plant defense responses, we suggest that dysfunctional peroxisomes contribute to CNV induced necrosis.
authors.affiliation: Agriculture and Agri-Food Canada Pacific Agri-Food Research Centre, 4200 Hwy 97, Summerland, BC, Canada V0H 1Z0; University of British Columbia Faculty of Land and Food Systems Vancouver, BC, Canada V6T 1Z4. Electronic address: Dann.Rochon@agr.gc.ca.
authors.forename: D'Ann
authors.initials: D
authors.lastname: Rochon
authors.affiliation: University of British Columbia Faculty of Land and Food Systems Vancouver, BC, Canada V6T 1Z4.
authors.forename: Bhavana
authors.initials: B
authors.lastname: Singh
authors.affiliation: Agriculture and Agri-Food Canada Pacific Agri-Food Research Centre, 4200 Hwy 97, Summerland, BC, Canada V0H 1Z0.
authors.forename: Ron
authors.initials: R
authors.lastname: Reade
authors.affiliation: Agriculture and Agri-Food Canada Pacific Agri-Food Research Centre, 4200 Hwy 97, Summerland, BC, Canada V0H 1Z0.
authors.forename: Jane
authors.initials: J
authors.lastname: Theilmann
authors.affiliation: University of British Columbia Faculty of Land and Food Systems Vancouver, BC, Canada V6T 1Z4.
authors.forename: Kankana
authors.initials: K
authors.lastname: Ghoshal
authors.affiliation: University of British Columbia Faculty of Land and Food Systems Vancouver, BC, Canada V6T 1Z4.
authors.forename: Syed Benazir
authors.initials: SB
authors.lastname: Alam
authors.affiliation: Agriculture and Agri-Food Canada Pacific Agri-Food Research Centre, 4200 Hwy 97, Summerland, BC, Canada V0H 1Z0; University of British Columbia Faculty of Land and Food Systems Vancouver, BC, Canada V6T 1Z4.
authors.forename: Ajay
authors.initials: A
authors.lastname: Maghodia
mesh_terms: D004721:Endoplasmic Reticulum / Q000821:virology*; D007181:Inclusion Bodies, Viral / Q000821:virology; D020675:Peroxisomes / Q000821:virology*; D021381:Protein Transport; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism*; D014026:Nicotiana / Q000821:virology*; D017864:Tombusvirus / Q000201:enzymology* / Q000235:genetics / Q000502:physiology*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
chemical_list: D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase
keywords: De novo peroxisome formation; Endoplasmic reticulum; Necrosis; Peroxisomes; RNA virus; Spherules; Tombusvirus