Genetics and genomics of prickle in roses
Génétique et Génomique des aiguillons de rosier
Résumé
Rose is the most important ornamental plant in the world and an interesting
model to study the genetic basis of original ornamental traits such as scent production,
seasonality of blooming or the presence of prickles. Our objective is to decipher the
molecular control of ornamental traits in rose by combining genetic and genomic
approaches. I will present here the last results we obtained concerning prickle
development. In rose, two types of prickles are present: non-glandular (NGP) and
glandular (GP) prickles. Prickles (NGP or GP) are originated from cells below the
protoderm clearly demonstrating that they correspond to prickles and not trichomes.
Four QTLs controlling the presence and density of prickles were identified. By
comparing the transcriptome of glabrous and prickle shoots, we identified key
regulators and interestingly demonstrated that homologous genes, which known to be
involved in trichome initiation and development, were not involved in prickle initiation
and development. These results suggest a unique developmental pathway for prickles
in rose. All these results contribute i) to well understand the genetic determinism of
ornamental traits, ii) to develop tools to help breeding, and iii) to eventually better
understand the rose domestication