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Identification and characterization of a new class of Tomato spotted wilt virus isolates that break Tsw ‐based resistance in a temperature‐dependent manner
Author(s) -
Ronde D.,
Lohuis D.,
Kormelink R.
Publication year - 2019
Publication title -
plant pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.928
H-Index - 85
eISSN - 1365-3059
pISSN - 0032-0862
DOI - 10.1111/ppa.12952
Subject(s) - biology , agroinfiltration , gene silencing , tomato spotted wilt virus , gene , rna silencing , rna interference , virology , rna , genetics , plant virus , virus
The single dominant Tsw resistance gene from Capsicum chinense against the Tomato spotted wilt orthotospovirus ( TSWV ) is temperature sensitive, i.e. the resistance fails to function at or above 32 °C. This study describes a new class of temperature‐sensitive resistance‐breaking TSWV isolates that induce Tsw ‐mediated resistance at T < 28 °C but at T ≥ 28 °C break this resistance. The NSs genes from these isolates were cloned and expressed to be analysed for RNA silencing suppressor ( RSS ) activity and the ability to induce a Tsw ‐mediated hypersensitive response ( HR ) in C. chinense and Capsicum annuum ( Tsw +). Unlike in viral infection, transient expression of some of the NS s proteins at standard temperatures (22 °C) did not induce Tsw ‐mediated HR , although varying degrees of RSS activity were observed. Attempts to express and test the NS s proteins for functionality at an elevated temperature through agroinfiltration remained unsuccessful. The NS s proteins of some TSWV resistance‐breaking ( RB ) isolates were analysed and found to lack amino acid residues that were previously shown to be important for RNA silencing suppression and avirulence. This study describes a new class of resistance‐breaking TSWV isolates that may be of importance for breeders and growers and for which the underlying mechanism still remains unknown.