title: Regulation of flavonoid biosynthesis involves an unexpected complex transcriptional regulation of TT8 expression, in Arabidopsis.
abstract: TT8/bHLH042 is a key regulator of anthocyanins and proanthocyanidins (PAs) biosynthesis in Arabidopsis thaliana. TT8 transcriptional activity has been studied extensively, and relies on its ability to form, with several R2R3-MYB and TTG1 (WD-Repeat protein), different MYB-bHLH-WDR (MBW) protein complexes. By contrast, little is known on how TT8 expression is itself regulated. Transcriptional regulation of TT8 expression was studied using molecular, genetic and biochemical approaches. Functional dissection of the TT8 promoter revealed its modular structure. Two modules were found to specifically drive TT8 promoter activity in PA- and anthocyanin-accumulating cells, by differentially integrating the signals issued from different regulators, in a spatio-temporal manner. Interestingly, this regulation involves at least six different MBW complexes, and an unpredicted positive feedback regulatory loop between TT8 and TTG2. Moreover, the results suggest that some putative new regulators remain to be discovered. Finally, specific cis-regulatory elements through which TT8 expression is regulated were identified and characterized. Together, these results provide a molecular model consistent with the specific and highly regulated expression of TT8. They shed new light into the transcriptional regulation of flavonoid biosynthesis and provide new clues and tools for further investigation in Arabidopsis and other plant species.
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Wenjia
authors: W
authors: Xu
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Damaris
authors: D
authors: Grain
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: José
authors: J
authors: Le Gourrierec
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Erwana
authors: E
authors: Harscoët
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Adeline
authors: A
authors: Berger
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Vincent
authors: V
authors: Jauvion
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Aurélie
authors: A
authors: Scagnelli
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Nathalie
authors: N
authors: Berger
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Przemyslaw
authors: P
authors: Bidzinski
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Zsolt
authors: Z
authors: Kelemen
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Fabien
authors: F
authors: Salsac
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Antoine
authors: A
authors: Baudry
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Jean-Marc
authors: JM
authors: Routaboul
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Loïc
authors: L
authors: Lepiniec
authors: INRA, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.|AgroParisTech, Institut Jean-Pierre Bourgin, Saclay Plant Sciences, UMR1318, RD10, F-78026, Versailles, France.
authors: Christian
authors: C
authors: Dubos
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics* / Q000378:metabolism; D005419:Flavonoids / Q000096:biosynthesis*; D018506:Gene Expression Regulation, Plant; D046912:Multiprotein Complexes / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D005419:Flavonoids; D046912:Multiprotein Complexes; D014157:Transcription Factors; C417767:TT8 protein, Arabidopsis
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