title: RNA-dependent RNA polymerase 1 in potato (Solanum tuberosum) and its relationship to other plant RNA-dependent RNA polymerases.
abstract: Cellular RNA-dependent RNA polymerases (RDRs) catalyze synthesis of double-stranded RNAs that can serve to initiate or amplify RNA silencing. Arabidopsis thaliana has six RDR genes; RDRs 1, 2 and 6 have roles in anti-viral RNA silencing. RDR6 is constitutively expressed but RDR1 expression is elevated following plant treatment with defensive phytohormones. RDR1 also contributes to basal virus resistance. RDR1 has been studied in several species including A. thaliana, tobacco (Nicotiana tabacum), N. benthamiana, N. attenuata and tomato (Solanum lycopersicum) but not to our knowledge in potato (S. tuberosum). StRDR1 was identified and shown to be salicylic acid-responsive. StRDR1 transcript accumulation decreased in transgenic potato plants constitutively expressing a hairpin construct and these plants were challenged with three viruses: potato virus Y, potato virus X, and tobacco mosaic virus. Suppression of StRDR1 gene expression did not increase the susceptibility of potato to these viruses. Phylogenetic analysis of RDR genes present in potato and in a range of other plant species identified a new RDR gene family, not present in potato and found only in Rosids (but apparently lost in the Rosid A. thaliana) for which we propose the name RDR7.
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.|The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Lydia J R
authors.initials: LJ
authors.lastname: Hunter
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Samuel F
authors.initials: SF
authors.lastname: Brockington
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Alex M
authors.initials: AM
authors.lastname: Murphy
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: Adrienne E
authors.initials: AE
authors.lastname: Pate
authors.affiliation: National Institute of Biology, Večna pot 111, 1000 Ljubljana, Slovenia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Gruden
authors.affiliation: The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: MacFarlane
authors.affiliation: The James Hutton Institute, Invergowrie, Dundee DD2 5DA, UK.|Division of Environmental and Life Sciences, Seoul Women's University, Seoul, Republic of Korea.
authors.forename: Peter
authors.initials: P
authors.lastname: Palukaitis
authors.affiliation: Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
authors.forename: John P
authors.initials: JP
authors.lastname: Carr
mesh_terms: D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D054884:Host-Pathogen Interactions; D010935:Plant Diseases / Q000235:genetics / Q000821:virology; D010940:Plant Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D017863:Potexvirus / Q000502:physiology; D017800:Potyvirus / Q000502:physiology; D034622:RNA Interference; D012324:RNA-Dependent RNA Polymerase / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020156:Salicylic Acid / Q000378:metabolism / Q000494:pharmacology; D011198:Solanum tuberosum / Q000201:enzymology / Q000235:genetics* / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000502:physiology
chemical_list: D010940:Plant Proteins; D012324:RNA-Dependent RNA Polymerase; D020156:Salicylic Acid