title: Amino acids in Tobamovirus coat protein controlling pepper L(1a)  gene-mediated resistance.
abstract: In pepper plants (genus Capsicum), the resistance against Tobamovirus spp. is conferred by L gene alleles. The recently identified L variant L(1a) can recognize coat proteins (CPs) of Tobacco mild green mosaic virus Japanese strain (TMGMV-J) and Paprika mild mottle virus Japanese strain (PaMMV-J), but not of Pepper mild mottle virus (PMMoV), as the elicitor to induce resistance at 24 °C. Interestingly, L(1a) gene-mediated resistance against TMGMV-J, but not PaMMV-J, is retained at 30 °C. This observation led us to speculate that L(1a) can discriminate between CPs of TMGMV-J and PaMMV-J. In this study, we aimed to determine the region(s) in CP by which L(1a) distinguishes TMGMV-J from PaMMV-J. By using chimeric CPs consisting of TMGMV-J and PaMMV-J, we found that the chimeric TMGMV-J CP, whose residues in the β-sheet domain were replaced by those of PaMMV-J, lost its ability to induce L(1a) gene-mediated resistance at 30 °C. In contrast, the chimeric PaMMV-J CP with the β-sheet domain replaced by TMGMV-J CP was able to induce L(1a) gene-mediated resistance at 30 °C. Furthermore, viral particles were not detected in the leaves inoculated with either chimeric virus. These observations indicated that the amino acids within the β-sheet domain were involved in both the induction of L(1a) gene-mediated resistance and virion formation. Further analyses using chimeric CPs of TMGMV-J and PMMoV indicated that amino acids within the β-sheet domain alone were not sufficient for the induction of L(1a) gene-mediated resistance by TMGMV-J CP. These results suggest that multiple regions in Tobamovirus CP are implicated in the induction of L(1a) gene-mediated resistance.
authors.affiliation: Laboratory of Plant Pathology and Biotechnology, Kochi University, Nankoku, Kochi 783-8502, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mizumoto
authors.forename: Ikumi
authors.initials: I
authors.lastname: Nakamura
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Shimomoto
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Sawada
authors.forename: Reiko
authors.initials: R
authors.lastname: Tomita
authors.forename: Ken-Taro
authors.initials: KT
authors.lastname: Sekine
authors.forename: Akinori
authors.initials: A
authors.lastname: Kiba
authors.forename: Masamichi
authors.initials: M
authors.lastname: Nishiguchi
authors.forename: Kappei
authors.initials: K
authors.lastname: Kobayashi
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Hikichi
mesh_terms: D000595:Amino Acid Sequence; D002212:Capsicum / Q000235:genetics* / Q000821:virology; D036022:Capsid Proteins / Q000737:chemistry*; D017343:Genes, Plant; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D017898:Tobamovirus / Q000502:physiology*; D014771:Virion
chemical_list: D036022:Capsid Proteins