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Article|05 Jan 2022|OPEN
The NAC-like transcription factor CsNAC7 positively regulates the caffeine biosynthesis-related gene yhNMT1 in Camellia sinensis
Wenhui Ma1 , Xin Kang1 , Ping Liu1 , Kexin She1 , Yuanyuan Zhang1 , Xiaorong Lin1 , Bin Li1,2 , , Zhongzheng Chen,1,2 ,
1College of Food Science, South China Agricultural University, 483 Wushan Street, Tianhe District, Guangzhou, Guangdong, 510642, China
2Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, South China Agricultural University, Guangzhou, Guangdong, 510642, China
*Corresponding author. E-mail: bli@scau.edu.cn,zhongzhengch@scau.edu.cn

Horticulture Research 9,
Article number: uhab046 (2022)
doi: https://doi.org/10.1093/hr/uhab046
Views: 191

Received: 22 Sep 2020
Revised: 29 Jul 2021
Accepted: 17 Aug 2021
Published online: 05 Jan 2022

Abstract

Caffeine is an important functional substance and is abundant in tea plant, but little is known about how its biosynthesis is regulated by transcription factors. In this study, the NAC-like transcription factor-encoding gene CsNAC7, which is involved in caffeine synthesis, was isolated from a Yinghong 9 cDNA library using a yeast one-hybrid assay; this gene comprises 1371 bp nucleotides and is predicted to encode 456 amino acids. The expression of CsNAC7 at the transcriptional level in tea shoots shared a similar pattern with that of the caffeine synthase gene yhNMT1 in the spring and summer, and its expressed protein was localized in the nucleus. Assays of gene activity showed that CsNAC7 has self-activation activity in yeast, that the active region is at the N-terminus, and that the transient expression of CsNAC7 could significantly promote the expression of yhNMT1 in tobacco leaves. In addition, overexpression or silencing of CsNAC7 significantly increased or decreased the expression of yhNMT1 and the accumulation of caffeine in transgenic tea calli, respectively. Our data suggest that the isolated transcription factor CsNAC7 positively regulates the caffeine synthase gene yhNMT1 and promotes caffeine accumulation in tea plant.