A spectrum of HRT-dependent hypersensitive responses elicited by the 52 amino acid N-terminus of turnip crinkle virus capsid protein and its mutants

Authors

Sung-Hwan Kang, University of Nebraska–Lincoln
Feng Qu, Ohio State UniversityFollow
Thomas Jack Morris, University of Nebraska-LincolnFollow

Date of this Version

2015

Citation

Published in Virus Research 200 (2015), pp 30–34.

doi 10.1016/j.virusres.2015.01.020

Comments

Copyright © 2015 Elsevier B.V. Used by permission.

Abstract

The capsid protein (CP) of turnip crinkle virus (TCV) is the elicitor of hypersensitive response (HR) and resistance mediated by the resistance protein HRT in the Di-17 ecotype of Arabidopsis. Here we identified the N-terminal 52-amino-acid R domain of TCV CP as the elicitor of HRT-dependent HR in Nicotiana benthamiana. Mutating this domain at position 6 (R6A), but not at positions 8 (R8A) or 14 (G14A), abolished HR in N. benthamiana. However, on Di-17 Arabidopsis leaves only R8A R domain elicited visible epidermal HR. When incorporated in infectious TCV RNAs, R8A and G14A mutations exerted dramatically different effects in Di-17 plants, as R8A caused systemic cell death whereas G14A led to complete restriction of the mutant virus. This continual spectrum of HR and resistance responses elicited by various R domain mutants suggests that the CP–HRT interaction could be perturbed by conformational changes in the R domain of TCV CP.