The rose is the most sells flower around the world and it has a prominent place in horticulture and in the perfume industry, which is why studies to clarify the cellular mechanisms of perfume emission have been undertaken. Previous work has enabled to deliver a hypothesis is that the scent would be mediated by lipid vesicles. Our observations showed that the vesicles are composed of a central matrix with a TG concentrate surrounded by a single sheet phospholipid membrane. These patterns support the theory that oil bodies purified from rose petals are oleosomes. However, the oleosin, a marker protein of this compartment has not been identified. The vesicles appear to be involved in the storage of biosynthetic pathways enzymes of perfumes, and fragrances themselves. The RhPAAS gene, involved in the biosynthesis of 2-phenylethanol, was also studied. Preliminary work showed that the major QTL explaining the presence of 2-phenylethanol to Rosa wichuraiana and the RhPAAS gene are localized on the same locus in linkage group B7. The modulation of gene expression RhPAAS has been a hypothesis to explain the presence or absence of 2-phenylethanol in the population HW. Indeed, at BJO stage, only the descendants producing much 2-phenylethanol, expresses RhPAAS. The transcript is accumulated in petals at BJO stage that is to say before the maximum emission of fragrance. The a1 allele linked to the production of 2-phenylethanol was identified while another allele is expressed only in roses producing few 2-phenylethanol
