Validated MAGIC and GWAS population mapping reveals the link between vitamin E content and natural variation in chorismate metabolism in tomato.

Tocochromanols constitute the different forms of vitamin E (VTE), essential components of the human diet, and display a high membrane protectant activity. By combining interval mapping and genome-wide association studies (GWAS), we unveiled the genetic determinants of tocochromanol accumulation in tomato (Solanum lycopersicum) fruits. To enhance the nutritional value of this highly consumed vegetable, we dissected the natural intraspecific variability of tocochromanols in tomato fruits and genetically engineered their biosynthetic pathway.

Involvement of the cylindrical inclusion (CI) protein in the overcoming of an eIF4E-mediated resistance against Lettuce mosaic potyvirus.

The capacity of Lettuce mosaic virus to overcome the lettuce resistance conferred by the mo1(1) and mo1(2) alleles of the gene for eukaryotic translation initiation factor 4E (eIF4E) was analysed using reverse genetics. Mutations in the virus genome-linked protein (VPg) allowed mo1(1) only to be overcome, but mutations in the C-terminal portion of the cylindrical inclusion (CI) protein allowed both alleles to be overcome. Site-directed mutagenesis pinpointed a key role of the amino acid at position 621 in the virulence.

Specific detection of lettuce mosaic virus isolates belonging to the "Most" type.

Lettuce mosaic virus (LMV)-Most isolates can infect and are seed-borne in cultivars containing the mo1 gene. A reverse transcription and polymerase chain reaction (RT-PCR)-based test was developed for the specific detection of LMV-Most isolates. Based on the complete genome sequences of three LMV isolates belonging respectively to the Most type, the Common type and neither of these two types, three different assays were compared: (i) presence of a diagnostic restriction site in the region of the genome encoding the variable N-terminus of the capsid protein, in the 3' end of the genome, (ii) RT-PCR using primers designed to amplify a cDNA corresponding to a portion of the P1 coding region, in the 5' end of the genome and (iii) RT-PCR using primers designed to amplify a central region of the genome.

Multiple resistance phenotypes to Lettuce mosaic virus among Arabidopsis thaliana accessions.

With the aim to characterize plant and viral factors involved in the molecular interactions between plants and potyviruses, a Lettuce mosaic virus (LMV)-Arabidopsis thaliana pathosystem was developed. Screening of Arabidopsis accessions with LMV isolates indicated the existence of a large variability in the outcome of the interaction, allowing the classification of Arabidopsis accessions into seven susceptibility groups. Using a reverse genetic approach, the genome-linked protein of LMV, a multifunctional protein shown to be involved in viral genome amplification and movement of potyviruses, was established as the viral determinant responsible for the ability to overcome the resistance of the Niederzenz accession to LMV-0.