title: Silencing of a gene encoding a protein component of the oxygen-evolving complex of photosystem II enhances virus replication in plants.
abstract: It has been suggested that, in addition to viral proteins, host proteins are involved in RNA virus replication. In this study the RNA helicase domain of the Tobacco mosaic virus (TMV) replicase proteins was used as bait in the yeast two-hybrid system to identify tobacco proteins with a putative role in TMV replication. Two host proteins were characterized. One protein (designated #3) belongs to a protein family of ATPases associated with various activities (AAA), while the second host protein (designated #13) is the 33K subunit of the oxygen-evolving complex of photosystem II. Using Tobacco rattle virus vectors, genes #3 and #13 were silenced in Nicotiana benthamiana, after which the plants were challenged by TMV infection. Silencing of gene #13 resulted in a 10-fold increase of TMV accumulation, whereas silencing of gene #3 caused a twofold reduction of TMV accumulation. Additionally, silencing of genes #3 and #13 decreased and increased, respectively, the accumulation of two other viruses. Similar to silencing of gene #13, inhibition of photosystem II by application of an herbicide increased TMV accumulation several fold. Infection of N. benthamiana with TMV resulted in a decrease of #13 mRNA levels. Silencing of gene #13 may reflect a novel strategy of TMV to suppress basal host defense mechanisms. The two-hybrid screenings did not identify tobacco proteins involved in helicase domain-induced N-mediated resistance.
authors.affiliation: Institute of Molecular Plant Sciences, Gorlaeus Laboratories, Leiden University, 2300 RA, The Netherlands.
authors.forename: Truus E M
authors.initials: TE
authors.lastname: Abbink
authors.forename: Jack R
authors.initials: JR
authors.lastname: Peart
authors.forename: Thera N M
authors.initials: TN
authors.lastname: Mos
authors.forename: David C
authors.initials: DC
authors.lastname: Baulcombe
authors.forename: John F
authors.initials: JF
authors.lastname: Bol
authors.forename: Huub J M
authors.initials: HJ
authors.lastname: Linthorst
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D004237:Diuron / Q000494:pharmacology; D020868:Gene Silencing; D006540:Herbicides / Q000494:pharmacology; D008969:Molecular Sequence Data; D010100:Oxygen / Q000378:metabolism; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D045332:Photosystem II Protein Complex; D010935:Plant Diseases / Q000821:virology; D018515:Plant Leaves / Q000821:virology; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020365:RNA Helicases / Q000378:metabolism*; D014026:Nicotiana / Q000187:drug effects / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D020798:Two-Hybrid System Techniques; D014779:Virus Replication
chemical_list: D006540:Herbicides; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D004237:Diuron; D000251:Adenosine Triphosphatases; D020365:RNA Helicases; D010100:Oxygen