title: Identification and characterization of cis-acting elements involved in the regulation of ABA- and/or GA-mediated LuPLR1 gene expression and lignan biosynthesis in flax (Linum usitatissimum L.) cell cultures.
abstract: Pinoresinol lariciresinol reductase 1, encoded by the LuPLR1 gene in flax (Linum usitatissimum L.), is responsible for the biosynthesis of (+)-secoisolariciresinol, a cancer chemopreventive phytoestrogenic lignan accumulated in high amount in the hull of flaxseed. Our recent studies have demonstrated a key role of abscisic acid (ABA) in the regulation of LuPLR1 gene expression and thus of the (+)-secoisolariciresinol synthesis during the flax seedcoat development. It is well accepted that gibberellins (GA) and ABA play antagonistic roles in the regulation of numerous developmental processes; therefore it is of interest to clarify their respective effects on lignan biosynthesis. Herein, using flax cell suspension cultures, we demonstrate that LuPLR1 gene expression and (+)-secoisolariciresinol synthesis are up-regulated by ABA and down-regulated by GA. The LuPLR1 gene promoter analysis and mutation experiments allow us to identify and characterize two important cis-acting sequences (ABRE and MYB2) required for these regulations. These results imply that a cross-talk between ABA and GA signaling orchestrated by transcription factors is involved in the regulation of lignan biosynthesis. This is particularly evidenced in the case of the ABRE cis-regulatory sequence of LuPLR1 gene promoter that appears to be a common target sequence of GA and ABA signals.
authors.affiliation: Laboratoire de Biologie des Ligneux et des Grandes Cultures (LBLGC), EA 1207, Antenne Scientifique Universitaire de Chartres (ASUC), Université d'Orléans, 21 rue de Loigny la Bataille, F28000, Chartres, France.
authors.forename: Cyrielle
authors.initials: C
authors.lastname: Corbin
authors.forename: Sullivan
authors.initials: S
authors.lastname: Renouard
authors.forename: Tatiana
authors.initials: T
authors.lastname: Lopez
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lamblin
authors.forename: Eric
authors.initials: E
authors.lastname: Lainé
authors.forename: Christophe
authors.initials: C
authors.lastname: Hano
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D053898:Biosynthetic Pathways / Q000187:drug effects / Q000235:genetics; D002072:Butylene Glycols / Q000737:chemistry / Q000494:pharmacology; D018929:Cell Culture Techniques / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D019597:Flax / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant / Q000235:genetics; D005875:Gibberellins / Q000494:pharmacology*; D005966:Glucuronidase / Q000378:metabolism; D017705:Lignans / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D014170:Transformation, Genetic / Q000187:drug effects
chemical_list: D002072:Butylene Glycols; D005875:Gibberellins; D017705:Lignans; D000040:Abscisic Acid; C007842:gibberellic acid; D010088:Oxidoreductases; C084968:lariciresinol reductase; D005966:Glucuronidase; C060283:secoisolariciresinol