title: Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesis.
abstract: Globe artichoke (Cynara cardunculus var. scolymus) belongs to the Asteraceae family, in which one of the most biologically significant class of secondary metabolites are sesquiterpene lactones (STLs). In globe artichoke the principal STL is the cynaropicrin, which contributes to approximately 80% of its characteristic bitter taste. Cynaropicrin content was assessed in globe artichoke tissues and was observed to accumulate in leaves of different developmental stages. In the receptacle, a progressive decrease was observed during inflorescence development, while the STL could not be detected in the inflorescence bracts. Almost undetectable amounts were found in the roots and inflorescence stems at the commercial stage. Cynaropicrin content was found to correlate with expression of genes encoding CcGAS, CcGAO and CcCOS, which are involved in the STL biosynthesis. A more detailed study of leaf material revealed that cynaropicrin predominantly accumulates in the trichomes, and not in the apoplastic cavity fluids. Analysis of the promoter regions of CcGAO and CcCOS revealed the presence of L1-box motifs, which confers trichome-specific expression in Arabidopsis, suggesting that cynaropicrin is not only stored but also synthesized in trichomes. A transient expression of GFP fusion proteins was performed in Nicotiana benthamiana plants: the CcGAS fluorescence signal was located in the cytoplasm while the CcGAO and CcCOS localized to the endoplasmatic reticulum.
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, Italy.
authors.forename: K
authors.initials: K
authors.lastname: Eljounaidi
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Comino
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, Italy. Electronic address: andrea.moglia@unito.it.
authors.forename: A
authors.initials: A
authors.lastname: Moglia
authors.affiliation: Plant Research International, P.O. Box 16, 6700 AA Wageningen, The Netherlands; Laboratory of Plant Physiology, Wageningen University, P.O. Box 658, 6700 AR Wageningen, The Netherlands.
authors.forename: K
authors.initials: K
authors.lastname: Cankar
authors.affiliation: Department of Life Sciences and Systems Biology, University of Turin, Viale Mattioli 25, 10125 Turin, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Genre
authors.affiliation: Université de Lorraine, UMR 1121 Agronomie et Environnement, 2 avenue de la Forêt de Haye, TSA 40602, 54518 Vandoeuvre-lès-Nancy, France; INRA, UMR 1121 Agronomie et Environnement, 2 avenue de la Forêt de Haye, TSA 40602, 54518 Vandoeuvre-lès-Nancy, France.
authors.forename: A
authors.initials: A
authors.lastname: Hehn
authors.affiliation: Université de Lorraine, UMR 1121 Agronomie et Environnement, 2 avenue de la Forêt de Haye, TSA 40602, 54518 Vandoeuvre-lès-Nancy, France; INRA, UMR 1121 Agronomie et Environnement, 2 avenue de la Forêt de Haye, TSA 40602, 54518 Vandoeuvre-lès-Nancy, France.
authors.forename: F
authors.initials: F
authors.lastname: Bourgaud
authors.affiliation: Plant Research International, P.O. Box 16, 6700 AA Wageningen, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Beekwilder
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Turin, Largo Paolo Braccini 2, 10095 Grugliasco, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Lanteri
mesh_terms: D031943:Cynara scolymus / Q000201:enzymology / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D007783:Lactones / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012717:Sesquiterpenes / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D007783:Lactones; D010940:Plant Proteins; D012717:Sesquiterpenes; C075687:cynaropicrin
keywords: Cynaropicrin; Globe artichoke; Sesquiterpene lactone; Trichomes