A Sucrose-Induced MYB (SIMYB) Transcription Factor
Promoting Proanthocyanidin Accumulation in the Tea Plant (<i>Camellia sinensis</i>)
Peiqiang Wang
Guoliang Ma
Lingjie Zhang
Yan Li
Zhouping Fu
Xinyi Kan
Yahui Han
Haiyan Wang
Xiaolan Jiang
Yajun Liu
Liping Gao
Tao Xia
10.1021/acs.jafc.8b06207.s002
https://acs.figshare.com/articles/journal_contribution/A_Sucrose-Induced_MYB_SIMYB_Transcription_Factor_Promoting_Proanthocyanidin_Accumulation_in_the_Tea_Plant_i_Camellia_sinensis_i_/7635947
Proanthocyanidins
(PAs, also called condensed tannins), are an
important class of secondary metabolites and exist widely in plants.
Tea (<i>Camellia sinensis</i>) is rich in PAs and their
precursors, (−)-epicatechin (EC) and (+)-catechin (C). The
biosynthesis of PAs is constantly regulated by many different MBW
complexes, consisting of MYB transcription factors (TFs), basic-helix–loop–helix
(bHLH) TFs, and WD-repeat (WDR) proteins. These regulatory factors
can be environmentally affected, such as by biotic and abiotic stresses.
In this study, we revalidated the effect of sucrose treatment on tea
branches, and a sucrose-induced MYB (SIMYB) TF was screened and studied.
Phylogenetic analysis indicted that this SIMYB TF belonged to MYB
subgroup 5, named CsMYB5b. Heterologous expression of <i>CsMYB5b</i> in tobacco strongly induced PA accumulation, through up-regulating
the key target genes <i>LAR</i> or <i>ANRs</i>. In addition, CsMYB5b restored PA production in the seed coat of <i>A. thaliana tt2</i> mutant and rescued its phenotype. Yeast
two-hybrid assay demonstrated CsMYB5b can interact directly with CsTT8
(an AtTT8 ortholog) and CsWD40 protein. Linking to the expression
profiling of <i>CsMYB5b</i> and the PA accumulation pattern
in tea plants suggest that the CsMYB5b acts as an important switch
for the synthesis of monomeric catechins and PAs. Therefore, these
data provide insight into the regulatory mechanisms controlling the
biosynthesis of PAs.
2019-01-26 17:29:25
WDR
PA accumulation pattern
AtTT 8 ortholog
CsMYB 5b acts
Camellia sinensis
SIMYB
Yeast two-hybrid assay
thaliana tt 2
EC
ANR
CsWD 40 protein
CsMYB 5b Heterologous expression
TF
MBW
CsMYB 5b
target genes LAR
Transcription Factor Promoting Proanthocyanidin Accumulation
MYB transcription factors