摘要
Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathways may compete for substrates.However,the mechanism regulating this potential competition remains unclear.Here,we identified GhMYB1a,an R2R3-MYB transcription factor involved in the regulation of anthocyanin and flavonol accumulation in gerbera(Gerbera hybrida).GhMYB1a shares high sequence similarity with that of other characterized regulators of flavonol biosynthesis.In addition,GhMYB1a is also phylogenetically grouped with these proteins.The overexpression of GhMYB1a in gerbera and tobacco(Nicotiana tabacum)resulted in decreased anthocyanin accumulation and increased accumulation of flavonols by upregulating the structural genes involved in flavonol biosynthesis.We further found that GhMYB1a functions as a homodimer instead of interacting with basic helix-loop-helix cofactors.These results suggest that GhMYB1a is involved in regulating the anthocyanin and flavonol metabolic pathways through precise regulation of gene expression.The functional characterization of GhMYB1a provides insight into the biosynthesis and regulation of flavonols and anthocyanins.
基金
supported by the Foundation of Guangzhou Science and Technology Project(201904010127 to C.Z.)
National Natural Science Foundation of China(Grants 31372099,31601784,and 31672188 to X.W.,L.L.and Y.W.,respectively)
Open Project Foundation of South China Normal University(2018KF0202 to C.Z.)
Specialized Research Fund for Graduate Students at South China Normal University(2014ssxm26).
