P0045
Characterization of PVY (Potato Virus Y) Resistance in Tobacco: Potential Role of an eIF4E Gene Identified by High Throughput Sequencing Technologies
In tobacco, a large deletion conferring resistance to PVY, the “va” gene, is commonly used. This resistance is associated sometimes with lower quality, maybe due to the absence of several other genes.
In a range of plant species, particularly in Solanaceae, it has been shown that amino acid substitutions in the eukaryotic translation initiation factor 4E (eIF4E) result in recessive resistance to potyviruses.
In the present study, we have sequenced by Illumina the transcriptome of a dozen of tobacco F7 Recombinant Inbred Lines, segregating for PVY resistance. After comparison with a reference transcriptome and annotation, genes differentially expressed between resistant and susceptible plants were identified. About thirty candidates sequences were selected, among these a sequence annotated as a eukaryotic translation initiation factor was strongly expressed in susceptible plants, and not in resistant. Other candidates are mostly related to photosynthesis process.
The correlation between susceptibility and expression of this eIF4E sequence was confirmed by PCR in 100 F8 RILs: specific primers succeeded in amplifying this eIF4E in susceptible plants, and not in resistant, showing complete correlation.
A natural cultivar without “va” transcript but not altered for photosynthesis genes was identified. EMS mutations in this gene are now being studied to evaluate resistance against a wide range of PVY strains.
Quality could be restored with these new sources of resistance and potential of resistance could be increased.