recessive potyvirus resistance gene pot-1 is the tomato orthologue of the pepper pvr2-eIF4E gene

• Published in: Molecular genetics and genomics : MGG 2005-11, Vol.274 (4), p.346-353
• Main Authors: Ruffel, S, Gallois, J.L, Lesage, M.L, Caranta, C
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; amino acid sequences; binding proteins; Capsicum - genetics; Capsicum annuum; Chromosome Mapping; complementary DNA; disease resistance; DNA, Complementary - metabolism; DNA, Plant; eIF4E locus; Eukaryotic Initiation Factor-4E - genetics; eukaryotic translation initiation factor 4E; Gene Expression Regulation, Plant; Genes; Genes, Plant; Genetic Complementation Test; Genetic Linkage; genetic markers; Genetic Predisposition to Disease; Genetics; Genome; Genomics; Genotype; Immunity, Innate; Life Sciences; Lycopersicon; Lycopersicon esculentum; Lycopersicon esculentum - genetics; Models, Genetic; Molecular Sequence Data; Multigene Family; nucleotide sequences; Open Reading Frames; Plant Diseases - genetics; Plant Diseases - virology; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - physiology; Plant Viruses - genetics; Polymorphism, Genetic; Polymorphism, Restriction Fragment Length; pot-1 gene; pot-1 locus; Potato virus Y; Potyvirus; Potyvirus - genetics; Potyvirus - metabolism; Protein Conformation; Protein Structure, Secondary; recessive genes; restriction fragment length polymorphism; Reverse Transcriptase Polymerase Chain Reaction; Solanum; Solanum habrochaites; Solanum lycopersicum var. lycopersicum; Solanum tuberosum; Tobacco etch virus; tomatoes
• ISSN: 1617-4615; 1617-4623
• DOI: 10.1007/s00438-005-0003-x

The translation initiation factor 4E (eIF4E) has been implicated in naturally occurring resistance to Potato virus Y (PVY) determined by the pvr2 locus in pepper (Capsicum annuum). Here, the molecular basis of the recessive resistance to PVY and Tobacco etch virus (TEV) controlled by the pot-1 locus in tomato (Lycopersicon esculentum; now Solanum lycopersicum) was investigated. On the basis of genetic mapping data that indicated that pot-1 and pvr2 are located in syntenic regions of the tomato and pepper genomes, the possible involvement of eIF4E in pot-1-mediated resistance was assessed. Genetic mapping of members of the eIF4E multigenic family in tomato introgression lines revealed that an eIF4E locus indeed maps in the same genomic region as pot-1. By comparing eIF4E coding sequences between resistant and susceptible Lycopersicon genotypes, a small number of polymorphisms that co-segregate with the pot-1 locus were identified, suggesting that this gene could be involved in resistance to potyviruses. Functional complementation experiments using Potato virus X-mediated transient expression of eIF4E from a susceptible genotype in a resistant pepper genotype confirmed that a small number of amino acid substitutions in the eIF4E protein indeed account for resistance/susceptibility to both the PVY and TEV, and consequently that pot-1 and pvr2 are orthologues. Taken together, these results support the role of this eIF4E gene as a key component of recessive resistance to potyviruses, and validate the comparative genomic approach for the molecular characterization of recessive resistance genes.