Résumé
The mantled somaclonal variation of oil palm (Elaeis guineensis Jacq.) is morphologically similar to B-class MADS-box genes mutants: floral organs undergo a male-to-female homeotic conversion in flowers of both sexes. The negative economic consequences of this somaclonal variation on oil yields, as well as its variable incidence in clonal progenies, have made it necessary to understand the molecular mechanisms responsible for the variant phenotype. We have recently demonstrated that the splicing of EgDEF1, the APETALA3ortholog that is believed to be involved in the mantled floral phenotype, is significantly altered in variant flowers with respect to normal ones, resulting in the over-accumulation of a shorter, and potentially defective, transcript isoform (Jaligot et al., 2014). We are now attempting to determine through In Situ Hybridization whether these alternative transcripts could indeed compete within the same tissues. Also, because EgDEF1is inserted in a region of the oil palm genome that is rich in Transposable Elements (TEs), we are investigating the possibility that TEs might play a role in the onset of the variation in the course of the somatic embryogenesis process. (Texte intégral)