title: Genome-Wide Identification of BAHD Acyltransferases andIn vivoCharacterization of HQT-like Enzymes Involved in Caffeoylquinic Acid Synthesis in Globe Artichoke.
abstract: Globe artichoke (Cynara cardunculusL. var.scolymus) is a rich source of compounds promoting human health (phytonutrients), among them caffeoylquinic acids (CQAs), mainly represented by chlorogenic acid (CGA), and dicaffeoylquinic acids (diCQAs). The enzymes involved in their biosynthesis belong to the large family of BAHD acyltransferases. Following a survey of the globe artichoke genome, we identified 69 BAHD proteins carrying the catalytic site (HXXXD). Their phylogenetic analysis together with another 43 proteins, from 21 species, representative of the BAHD family, highlighted their grouping in seven major clades. Nine globe artichoke acyltransferases clustered in a sub-group of Clade V, with 3 belonging to hydroxycinnamoyl-CoA:quinate hydroxycinnamoyl transferase (HQT) and 2 to hydroxycinnamoyl-CoA:shikimate/quinate hydroxycinnamoyl transferase (HCT) like proteins. We focused our attention on the former, HQT1, HQT2, and HQT3, as they are known to play a key role in CGA biosynthesis. The expression of genes coding for the three HQTs and correlation of expression with the CQA content is reported for different globe artichoke tissues. For the first time in the globe artichoke, we developed and applied the virus-induced gene silencing approach with the goal of assessingin vivothe effect of HQT1 silencing, which resulted in a marked reduction of both CGA and diCQAs. On the other hand, when the role of the three HQTs was assessed in leaves ofNicotiana benthamianathrough their transient overexpression, significant increases in mono- and diCQAs content were observed. Using transient GFP fusion proteins expressed inN. benthamianaleaves we also established the sub-cellular localization of these three enzymes.
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Torino Grugliasco, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Moglia
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Torino Grugliasco, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Acquadro
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Torino Grugliasco, Italy.
authors.forename: Kaouthar
authors.initials: K
authors.lastname: Eljounaidi
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Torino Grugliasco, Italy.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Milani
authors.affiliation: Department of Drug Science and Technology, University of Torino Torino, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Cagliero
authors.affiliation: Department of Drug Science and Technology, University of Torino Torino, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Rubiolo
authors.affiliation: Department of Life Sciences and Systems Biology, University of Torino Torino, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Genre
authors.affiliation: Plant Research International Wageningen, Netherlands.
authors.forename: Katarina
authors.initials: K
authors.lastname: Cankar
authors.affiliation: Plant Research International Wageningen, Netherlands.
authors.forename: Jules
authors.initials: J
authors.lastname: Beekwilder
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Torino Grugliasco, Italy.
authors.forename: Cinzia
authors.initials: C
authors.lastname: Comino
keywords: BAHD acyltransferases; Cynara cardunculus; VIGS; caffeoylquinic acids; functional characterization