title: An induced mutation in tomato eIF4E leads to immunity to two potyviruses.
abstract: BACKGROUND
  The characterization of natural recessive resistance genes and Arabidopsis virus-resistant mutants have implicated translation initiation factors of the eIF4E and eIF4G families as susceptibility factors required for virus infection and resistance function.
  
  
  RESULTS
  To investigate further the role of translation initiation factors in virus resistance we set up a TILLING platform in tomato, cloned genes encoding for translation initiation factors eIF4E and eIF4G and screened for induced mutations that lead to virus resistance. A splicing mutant of the eukaryotic translation initiation factor, S.l_eIF4E1 G1485A, was identified and characterized with respect to cap binding activity and resistance spectrum. Molecular analysis of the transcript of the mutant form showed that both the second and the third exons were miss-spliced, leading to a truncated mRNA. The resulting truncated eIF4E1 protein is also impaired in cap-binding activity. The mutant line had no growth defect, likely because of functional redundancy with others eIF4E isoforms. When infected with different potyviruses, the mutant line was immune to two strains of Potato virus Y and Pepper mottle virus and susceptible to Tobacco each virus.
  
  
  CONCLUSIONS
  Mutation analysis of translation initiation factors shows that translation initiation factors of the eIF4E family are determinants of plant susceptibility to RNA viruses and viruses have adopted strategies to use different isoforms. This work also demonstrates the effectiveness of TILLING as a reverse genetics tool to improve crop species. We have also developed a complete tool that can be used for both forward and reverse genetics in tomato, for both basic science and crop improvement. By opening it to the community, we hope to fulfill the expectations of both crop breeders and scientists who are using tomato as their model of study.
authors.affiliation: Unité de Recherche en Génomique Végétale, UMR INRA-CNRS-Uni. EVRY, Evry, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Piron
authors.forename: Maryse
authors.initials: M
authors.lastname: Nicolaï
authors.forename: Silvia
authors.initials: S
authors.lastname: Minoïa
authors.forename: Elodie
authors.initials: E
authors.lastname: Piednoir
authors.forename: André
authors.initials: A
authors.lastname: Moretti
authors.forename: Aurélie
authors.initials: A
authors.lastname: Salgues
authors.forename: Dani
authors.initials: D
authors.lastname: Zamir
authors.forename: Carole
authors.initials: C
authors.lastname: Caranta
authors.forename: Abdelhafid
authors.initials: A
authors.lastname: Bendahmane
mesh_terms: D039561:Eukaryotic Initiation Factor-4E / Q000235:genetics*; D005091:Exons; D018551:Solanum lycopersicum / Q000235:genetics* / Q000276:immunology; D009154:Mutation; D017800:Potyvirus / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics
chemical_list: D039561:Eukaryotic Initiation Factor-4E; D012333:RNA, Messenger