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Zhou H, Lin-Wang K, Wang F, Espley RV, Ren F, Zhao J, Ogutu C, He H, Jiang Q, Allan AC, Han Y. Activator-type R2R3-MYB genes induce a repressor-type R2R3-MYB gene to balance anthocyanin and proanthocyanidin accumulation. New Phytol 2019; 221:1919-1934. [PMID: 30222199 DOI: 10.1111/nph.15486] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 09/12/2018] [Indexed: 05/22/2023]
Abstract
Anthocyanin and proanthocyanidin (PA) accumulation is regulated by both myeloblastosis (MYB) activators and repressors, but little information is available on hierarchical interactions between the positive and negative regulators. Here, we report on a R2R3-MYB repressor in peach, designated PpMYB18, which acts as a negative regulator of anthocyanin and PA accumulation. PpMYB18 can be activated by both anthocyanin- and PA-related MYB activators, and is expressed both at fruit ripening and juvenile stages when anthocyanins or PAs, respectively, are being synthesized. The PpMYB18 protein competes with MYB activators for binding to basic Helix Loop Helixes (bHLHs), which develops a fine-tuning regulatory loop to balance PA and anthocyanin accumulation. In addition, the bHLH binding motif in the R3 domain and the C1 and C2 repression motifs in the C-terminus of PpMYB18 both confer repressive activity of PpMYB18. Our study also demonstrates a modifying negative feedback loop, which prevents cells from excess accumulation of anthocyanin and PAs, and serves as a model for balancing secondary metabolite accumulation at the transcriptional level.
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Affiliation(s)
- Hui Zhou
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074, China
- Institute of Horticulture, Anhui Academy of Agricultural Sciences, Hefei, 230031, China
| | - Kui Lin-Wang
- The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag, Auckland, 92169, New Zealand
| | - Furong Wang
- Institute of Fruit Tree and Tea, Hubei Academy of Agricultural Sciences, Wuhan, 430209, China
| | - Richard V Espley
- The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag, Auckland, 92169, New Zealand
| | - Fei Ren
- Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China
| | - Jianbo Zhao
- Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China
| | - Collins Ogutu
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-African Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
| | - Huaping He
- Institute of Fruit Tree and Tea, Hubei Academy of Agricultural Sciences, Wuhan, 430209, China
| | - Quan Jiang
- Institute of Forestry and Pomology, Beijing Academy of Agriculture and Forestry Sciences, Beijing, 100097, China
| | - Andrew C Allan
- The New Zealand Institute for Plant & Food Research Ltd, Mt Albert Research Centre, Private Bag, Auckland, 92169, New Zealand
- School of Biological Sciences, University of Auckland, Auckland, 1020, New Zealand
| | - Yuepeng Han
- Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Wuhan Botanical Garden of the Chinese Academy of Sciences, Wuhan, 430074, China
- Sino-African Joint Research Center, Chinese Academy of Sciences, Wuhan, 430074, China
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An, 271018, China
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