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Chen S, Wu F, Li Y, Qian Y, Pan X, Li F, Wang Y, Wu Z, Fu C, Lin H, Yang A. NtMYB4 and NtCHS1 Are Critical Factors in the Regulation of Flavonoid Biosynthesis and Are Involved in Salinity Responsiveness. Front Plant Sci 2019; 10:178. [PMID: 30846995 PMCID: PMC6393349 DOI: 10.3389/fpls.2019.00178] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Accepted: 02/05/2019] [Indexed: 05/19/2023]
Abstract
High levels of salinity induce serious oxidative damage in plants. Flavonoids, as antioxidants, have important roles in reactive oxygen species (ROS) scavenging. In the present study, the tobacco R2R3 MYB type repressor, NtMYB4, was isolated and characterized. The expression of NtMYB4 was suppressed by salinity. Overexpression of NtMYB4 reduced the salt tolerance in transgenic tobacco plants. NtMYB4 repressed the promoter activity of NtCHS1 and negatively regulated its expression. Rutin accumulation was significantly decreased in NtMYB4 overexpressing transgenic plants and NtCHS1 RNAi silenced transgenic plants. Moreover, high H2O2 andO 2 - contents were detected in both types of rutin-reduced transgenic plants under high salt stress. In addition, exogenous rutin supplementation effectively scavenged ROS (H2O2 andO 2 - ) and improved the salt tolerance of the rutin-reduced transgenic plants. In contrast, NtCHS1 overexpressing plants had increased rutin accumulation, lower H2O2 andO 2 - contents, and higher tolerance to salinity. These results suggested that tobacco NtMYB4 acts as a salinity response repressor and negatively regulates NtCHS1 expression, which results in the reduced flavonoid accumulation and weakened ROS-scavenging ability under salt stress.
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Affiliation(s)
- Shuai Chen
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Fengyan Wu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Yiting Li
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Yanli Qian
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Xuhao Pan
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Fengxia Li
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Yuanying Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
| | - Zhenying Wu
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Chunxiang Fu
- Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Hao Lin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Aiguo Yang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China
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