title: Tobacco rattle virus 29K movement protein is the elicitor of extreme and hypersensitive-like resistance in two cultivars of Solanum tuberosum.
abstract: Leaf infection experiments were used to analyze the host responses of Solanum tuberosum cultivars known to be resistant or susceptible to natural, nematode-mediated infection of tubers and necrosis induction ("spraing") by Tobacco rattle virus (TRV) isolate PpK20 (TRV-PpK20). Extreme and hypersensitive-like resistance (ER and HR-like, respectively) as well as spreading veinal necrosis and systemic infection were observed. Agroinfection of leaves with a DsRed-expressing TRV cDNA clone revealed ER to function on the single-cell level, inhibiting virus replication and possessing the potential to initiate a cell death response. HR-like necrosis was characterized by initial virus replication and cell-to-cell movement before the onset of necrosis. Transient agroexpression and Potato virus X (PVX)-mediated expression assays demonstrated that the 29K-PpK20 movement protein (MP) can elicit ER and HR-like cell-death. A TRV isolate, PpO85M, known to overcome the resistance to spraing in plants that are resistant to TRV-PpK20 encoded a variant 29K protein which did not elicit HR in PpK20-HR plants. Our results show that the TRV MP is the elicitor of both ER and HR-like cell-death, that no other TRV-encoded proteins or RNA replication are required for its elicitor activity, and that the host reactions are likely to be controlled by single dominant resistance genes.
authors.affiliation: University of Göttingen, Department of Crop Sciences, Section Plant Virology, Grisebachstr. 6, 37077 Göttingen, Germany.
authors.forename: Walid
authors.initials: W
authors.lastname: Ghazala
authors.forename: Mark
authors.initials: M
authors.lastname: Varrelmann
mesh_terms: D004198:Disease Susceptibility; D015967:Gene Expression Regulation, Viral; D010935:Plant Diseases / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000494:pharmacology*; D010942:Plant Viruses / Q000378:metabolism*; D011198:Solanum tuberosum / Q000187:drug effects* / Q000821:virology; D014026:Nicotiana / Q000821:virology
chemical_list: D053830:Plant Viral Movement Proteins