Molecular Plant-Microbe Interactions (2012) 25, 1562-1573

Kari Perez, Inhwa Yeam, Byoung-Cheorl Kang, Daniel R. Ripoll, Jinhee Kim, John F. Murphy and Molly M. Jahn (2012)
Tobacco etch virus infectivity in Capsicum spp. is determined by a maximum of three amino acids in the viral virulence determinant VPg
Molecular Plant-Microbe Interactions 25 (12), 1562-1573
Abstract: Potyvirus resistance in Capsicum spp. has been attributed to amino acid substitutions at the pvr1 locus that cause conformational shifts in eukaryotic translation initiation factor eIF4E. The viral genome-linked protein (VPg) sequence was isolated and compared from three Tobacco etch virus (TEV) strains, highly aphid-transmissible (HAT), Mex21, and N, which differentially infect Capsicum genotypes encoding Pvr1+, pvr1, and pvr12. Viral chimeras were synthesized using the TEV-HAT genome, replacing HAT VPg with Mex21 or N VPg. TEV HAT did not infect pepper plants homozygous for either the pvr1 or pvr12 allele. However, the novel chimeric TEV strains, TEV-HAT^Mex21-VPg and TEV-HAT^N-VPg, infected pvr1 and pvr12 pepper plants, respectively, demonstrating that VPg is the virulence determinant in this pathosystem. Three-dimensional structural models predicted interaction between VPg and the susceptible eIF4E genotype in every case, while resistant genotypes were never predicted to interact. To determine whether there is a correlation between physical interaction of VPg with eIF4E and infectivity, the effects of amino acid variation within VPg were assessed. Interaction between pvr12 eIF4E and N VPg was detected in planta, implying that the six amino acid differences in N VPg relative to HAT VPg are responsible for restoring the physical interaction and infectivity.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): John F. Murphy

Research topic(s) for pests/diseases/weeds:
molecular biology - genes

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tobacco etch virus	Green pepper/chilli (Capsicum)