The Tomato spotted wilt virus cell-to-cell movement protein (NSM ) triggers a hypersensitive response in Sw-5-containing resistant tomato lines and in Nicotiana benthamiana transformed with the functional Sw-5b resistance gene copy.
Although the Sw-5 gene cluster has been cloned, and Sw-5b has been identified as the functional gene copy that confers resistance to Tomato spotted wilt virus (TSWV), its avirulence (Avr) determinant has not been identified to date. Nicotiana tabacum 'SR1' plants transformed with a copy of the Sw-5b gene are immune without producing a clear visual response on challenge with TSWV, whereas it is shown here that N. benthamiana transformed with Sw-5b gives a rapid and conspicuous hypersensitive response (HR). Using these plants, from all structural and non-structural TSWV proteins tested, the TSWV cell-to-cell movement protein (NSM ) was confirmed as the Avr determinant using a Potato virus X (PVX) replicon or a non-replicative pEAQ-HT expression vector system. HR was induced in Sw-5b-transgenic N. benthamiana as well as in resistant near-isogenic tomato lines after agroinfiltration with a functional cell-to-cell movement protein (NSM ) from a resistance-inducing (RI) TSWV strain (BR-01), but not with NSM from a Sw-5 resistance-breaking (RB) strain (GRAU). This is the first biological demonstration that Sw-5-mediated resistance is triggered by the TSWV NSM cell-to-cell movement protein.
Laboratory of Virology, Department of Plant Sciences, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands; Instituto de Ciências Biológicas, Departamento de Biologia Celular, Universidade de Brasília, ICC-Sul Asa Norte 70910-900, Brasília, DF, Brazil.
Mariana
M
Hallwass
Athos Silva
AS
de Oliveira
Erico
E
de Campos Dianese
Dick
D
Lohuis
Leonardo Silva
LS
Boiteux
Alice Kazuko
AK
Inoue-Nagata
Renato O
RO
Resende
Richard
R
Kormelink
D060467:Disease Resistance / Q000235:genetics*; D017343:Genes, Plant; D018551:Solanum lycopersicum / Q000235:genetics / Q000276:immunology* / Q000821:virology*; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000276:immunology / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D012093:Replicon; D014026:Nicotiana / Q000235:genetics* / Q000821:virology; D017865:Tospovirus / Q000502:physiology*; D014170:Transformation, Genetic
D053830:Plant Viral Movement Proteins
NSM; Sw-5; TSWV; avirulence; cell-to-cell movement; resistance gene; tospovirus