A Sucrose-Induced MYB (SIMYB) Transcription Factor Promoting Proanthocyanidin Accumulation in the Tea Plant (Camellia sinensis)

• DOI: 10.1021/acs.jafc.8b06207
• Publication Date: 2019-01-28T16:40:35Z
• Authors: Peiqiang Wang; Guoliang Ma; Lingjie Zhang; Yan Li; Zhouping Fu; Xinyi Kan; Yahui Han; Haiyan Wang; Xiaolan Jiang; Yajun Liu; Liping Gao; Tao Xia
• Keywords: Theaceae; MYB; Tannin

Proanthocyanidins (PAs, also called condensed tannins), are an important class of secondary metabolites and exist widely in plants. Tea (Camellia sinensis) is rich PAs their precursors, (−)-epicatechin (EC) (+)-catechin (C). The biosynthesis constantly regulated by many different MBW complexes, consisting MYB transcription factors (TFs), basic-helix–loop–helix (bHLH) TFs, WD-repeat (WDR) proteins. These regulatory can be environmentally affected, such as biotic abiotic stresses. In this study, we revalidated the effect sucrose treatment on tea branches, a sucrose-induced (SIMYB) TF was screened studied. Phylogenetic analysis indicted that SIMYB belonged to subgroup 5, named CsMYB5b. Heterologous expression CsMYB5b tobacco strongly induced PA accumulation, through up-regulating key target genes LAR or ANRs. addition, restored production seed coat A. thaliana tt2 mutant rescued its phenotype. Yeast two-hybrid assay demonstrated interact directly with CsTT8 (an AtTT8 ortholog) CsWD40 protein. Linking profiling accumulation pattern plants suggest acts switch for synthesis monomeric catechins PAs. Therefore, these data provide insight into mechanisms controlling