CsRAB, a R2R3-MYB transcription factor from purple tea (Camellia sinensis), positively regulates anthocyanin biosynthesis

Hualing Wu; Yayan Pan; Erdong Ni; Dandan Qin; Kaixing Fang; Qing Wang; Chengwei Yang; Ming Luo; Jun Liu

doi:10.3389/fpls.2024.1514631

CsRAB, a R2R3-MYB transcription factor from purple tea (Camellia sinensis), positively regulates anthocyanin biosynthesis

Front Plant Sci. 2024 Dec 6:15:1514631. doi: 10.3389/fpls.2024.1514631. eCollection 2024.

Authors

Hualing Wu^#¹, Yayan Pan^#^{1

2}, Erdong Ni^#¹, Dandan Qin¹, Kaixing Fang¹, Qing Wang¹, Chengwei Yang², Ming Luo³, Jun Liu¹

Affiliations

¹ Tea Research Institute, Guangdong Academy of Agricultural Sciences, Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization, Guangzhou, Guangdong, China.
² School of Life Science, South China Normal University, Guangzhou, Guangdong, China.
³ Guangdong Provincial Key Laboratory of Applied Botany & Agriculture and Biotechnology Research Center, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China.

^# Contributed equally.

Abstract

In tea (Camellia sinensis), anthocyanins are important secondary metabolites that are linked to leaf color. Anthocyanin biosynthesis is a complex biological process, in which multiple genes including structural and regulatory genes are involved. Here, we describe the cloning and characterizing of a new R2R3-MYB transcription factor gene, CsRAB, isolated from purple tea variety 'Hongfei'. Consistent with its predicted role as a transcription factor, the CsRAB protein localized to nuclei when expressed in onion (Allium cepa) epidermal cell. A dual-luciferase reporter assay demonstrated that CsRAB acts as a transcriptional activator in vivo. CsRAB overexpression in Arabidopsis seedlings led to higher expression levels of anthocyanin biosynthesis-related genes, and consequently, purple stems and higher anthocyanin contents were exhibited in overexpressing lines compared to wild type. The results indicated that CsRAB plays critical roles in positively regulating anthocyanins biosynthesis in tea plants.

Keywords: R2R3-MYB gene; anthocyanins; purple tea; secondary metabolism; tea (Camellia sinensis).

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. This work was supported by Key-Area Research and Development Program of Guangdong Province (2022B0202070001), the Special Funding for the Construction of the National Modern Agricultural Industry Technology System (CARS-19), the National Natural Science Foundation of China (31600550), Guang Dong Basic and Applied Basic Research Foundation (2021A1515110836), the National Tea Tree Breeding Joint Research Project (GJCSYZLHGG-03), Special Fund for Guangdong Rural Revitalization Strategy (2023-NBH-00-010), the Guangdong Provincial Key Laboratory of Tea Plant Resources Innovation and Utilization Innovation project (2021CX01) and the Guangdong Academy of Agricultural Sciences Science and technology talent introduction special project (R2021YJ-YB3013).