Breeding of resistance against TSWV sofar is limited to the availability of only two single dominant resistance (R) genes, namely Sw5 and Tsw.
While single dominant R genes are generally highly pathogen specific, e.g. Tsw only confers resistance to TSWV, Sw-5 is relatively unique in that it protects against a broader spectrum of tospoviruses, that include TSWV, Tomato chlorotic spot virus (TCSV), Groundnut ringspot virus (GRSV) and Impatiens necrotic spot virus (INSV).
Earlier we have identified the TSWV NSs RNA silencing suppressor protein (RSS) as trigger of Tsw-mediated resistance (De Ronde et al., 2013), and demonstrated the importance of the NSs N-terminal domain in RSS activity and avirulence (De Ronde et al., 2014). Just recently, we also have identified the TSWV NSm cell-to-cell movement protein as trigger of Sw5-mediated resistance (Silva de Oliveira, Hallwass et al., 2014). Using mutants or Avr variants of resistance breaker isolates, and (mutant/chimeric) R gene constructs, the Sw-5/Tsw-triggered resistance response and downstream signaling pathways are further investigated.