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FtSAD2 and FtJAZ1 regulate activity of the FtMYB11 transcription repressor of the phenylpropanoid pathway in Fagopyrum tataricum
Author(s) -
Zhou Meiliang,
Sun Zhanmin,
Ding Mengqi,
Logacheva Maria D.,
Kreft Ivan,
Wang Dan,
Yan Mingli,
Shao Jirong,
Tang Yixiong,
Wu Yanmin,
Zhu Xuemei
Publication year - 2017
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14692
Subject(s) - repressor , fagopyrum tataricum , myb , phenylpropanoid , bimolecular fluorescence complementation , psychological repression , transcription factor , juglone , biology , complementation , fagopyrum , biochemistry , microbiology and biotechnology , chemistry , gene , mutant , gene expression , botany , rutin , biosynthesis , antioxidant
Summary Little is known about the molecular mechanism of the R2R3‐ MYB transcriptional repressors involved in plant phenylpropanoid metabolism. Here, we describe one R2R3‐type MYB repressor, Ft MYB 11 from Fagopyrum tataricum . It contains the SID ‐like motif GGDFNFDL and it is regulated by both the importin protein ‘Sensitive to ABA and Drought 2’ ( SAD 2) and the jasmonates signalling cascade repressor JAZ protein. Yeast two hybrid and bimolecular fluorescence complementation assays demonstrated that Ft MYB 11 interacts with SAD 2 and Ft JAZ 1. Protoplast transactivation assays demonstrated that Ft MYB 11 acts synergistically with Ft SAD 2 or Ft JAZ 1 and directly represses its target genes via the MYB ‐core element AATAGTT . Changing the Asp122 residue to Asn in the SID ‐like motif results in cytoplasmic localization of Ft MYB 11 because of loss of interaction with SAD 2, while changing the Asp126 residue to Asn results in the loss of interaction with Ft JAZ 1. Overexpression of Ft MYB 11 or Ft MYB 11 D126N in F. tataricum hairy roots resulted in reduced accumulation of rutin, while overexpression of Ft MYB 11 D122N in hairy roots did not lead to such a change. The results indicate that Ft MYB 11 acts as a regulator via interacting with Ft SAD 2 or Ft JAZ 1 to repress phenylpropanoid biosynthesis, and this repression depends on two conserved Asp residues of its SID ‐like motif.