title: Hibiscus chlorotic ringspot virus upregulates plant sulfite oxidase transcripts and increases sulfate levels in kenaf (Hibiscus cannabinus L.).
abstract: Hibiscus chlorotic ringspot virus (HCRSV) coat protein (CP) is required for encapsidation and virus systemic movement. To better understand the roles of HCRSV CP in virus infection and its interactions with host proteins, a cDNA library of kenaf (Hibiscus cannabinus L.) was constructed and screened by using a yeast two-hybrid system (YTHS) to identify CP-interacting proteins. One protein identified was sulfite oxidase (SO) and the interaction was confirmed in vitro and in vivo. The interaction was found to be associated with peroxisomes by immunofluorescent labelling of peroxisomes by an anti-SKL signal peptide antibody. Our YTHS results showed that only the P and S domains of CP interacted with SO from kenaf. This is probably due to the exposure of these two domains on the outer surface of the capsid. Peroxisomes were observed to aggregate in HCRSV-infected cells, and biochemical assays of total protein from kenaf leaf extracts showed that SO activity and SO-dependent H(2)O(2)-generating activity in the HCRSV-infected leaves increased compared with that in mock-inoculated kenaf plants.
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Kent Ridge, Singapore 117543.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Temasek Life Sciences Laboratory, 1 Research Link, Singapore 117604.|Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, Kent Ridge, Singapore 117543.
authors.forename: Sek-Man
authors.initials: SM
authors.lastname: Wong
mesh_terms: D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D019184:Carmovirus / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D015723:Gene Library; D031584:Hibiscus / Q000378:metabolism / Q000821:virology*; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000378:metabolism / Q000821:virology; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism*; D050876:Sulfite Oxidase / Q000235:genetics / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D015854:Up-Regulation
chemical_list: D036022:Capsid Proteins; D010940:Plant Proteins; D013431:Sulfates; D050876:Sulfite Oxidase