Journal of Plant Pathology (2006) 88, p. S50 (Margaria et al.)

P. Margaria and M. Turina (2006)
Molecular characterization of resistancebreaking strains of Tomato spotted wilt virus carrying a deletion in the NSs coding region
Journal of Plant Pathology 88 (3, Special Issue), S50-S50
S.I.Pa.V XIII National Meeting - Foggia, 12-16 September 2006 - Poster
Abstract: The most effective and environmentally sound control strategy for Tomato spotted wilt virus (TSWV, Tospovirus, Bunyaviridae) relies on the availability of resistant cultivars. All known resistant pepper cultivars possess a single dominant resistance gene, Tsw, which is easily overcome by TSWV resistance-breaking (RB) strains. We provide evidence that the NSs protein of TSWV-RB strains on pepper is the avirulence factor, using reassortment experiments and full-length sequencing of a series of S genome segments cloned from a collection of TSWV-RB strains. Two of the RB strains carried a deletion in the NSs coding region. Strain p170RB was obtained from a Sicilian virus isolate through successive inoculations on resistant Capsicum chinensis PI152225 in a controlled environment. Strain p202 is an RB isolate from an infected plant from a field in the province of Palermo (Southern Italy). Host range and symptoms of these RB strains were compared with the wild type field isolate from Sicily (p170), which produces an NSs protein of 467 aa, while the S segment of p202 showed a two-base deletion at position 1171 producing a protein of 399 aa. p170RB showed a deletion of 25 nt at position 684, encoding a putative protein of 238 aa. The in vivo presence of the deleted forms of NSs protein was checked by Western blotting. Moreover, wild type NSs protein and the two deleted forms were transiently expressed through agroinfiltration in Nicotiana benthamiana C16 leaves in order to assess their silencing-suppressor potential.
Database assignments for author(s): Massimo Turina, Paolo Margaria

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Orthotospovirus tomatomaculae	Green pepper/chilli (Capsicum)