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Zheng X, Lan J, Yu H, Zhang J, Zhang Y, Qin Y, Su XD, Qin G. Arabidopsis transcription factor TCP4 represses chlorophyll biosynthesis to prevent petal greening. PLANT COMMUNICATIONS 2022; 3:100309. [PMID: 35605201 PMCID: PMC9284284 DOI: 10.1016/j.xplc.2022.100309] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 01/16/2022] [Accepted: 03/01/2022] [Indexed: 05/06/2023]
Abstract
Green petals pose a challenge for pollinators to distinguish flowers from leaves, but they are valuable as a specialty flower trait. However, little is understood about the molecular mechanisms that underlie the development of green petals. Here, we report that CINCINNATA (CIN)-like TEOSINTE BRANCHED 1/CYCLOIDEA/PCF (TCP) proteins play key roles in the control of petal color. The septuple tcp2/3/4/5/10/13/17 mutant produced flowers with green petals due to chlorophyll accumulation. Expression of TCP4 complemented the petal phenotype of tcp2/3/4/5/10/13/17. We found that chloroplasts were converted into leucoplasts in the distal parts of wild-type petals but not in the proximal parts during flower development, whereas plastid conversion was compromised in the distal parts of tcp2/3/4/5/10/13/17 petals. TCP4 and most CIN-like TCPs were predominantly expressed in distal petal regions, consistent with the green-white pattern in wild-type petals and the petal greening observed in the distal parts of tcp2/3/4/5/10/13/17 petals. RNA-sequencing data revealed that most chlorophyll biosynthesis genes were downregulated in the white distal parts of wild-type petals, but these genes had elevated expression in the distal green parts of tcp2/3/4/5/10/13/17 petals and the green proximal parts of wild-type petals. We revealed that TCP4 repressed chlorophyll biosynthesis by directly binding to the promoters of PROTOCHLOROPHYLLIDE REDUCTASE (PORB), DIVINYL REDUCTASE (DVR), and SUPPRESSOR OF OVEREXPRESSION OF CO 1 (SOC1), which are known to promote petal greening. We found that the conversion of chloroplasts to leucoplasts and the green coloration in the proximal parts of petals appeared to be conserved among plant species. Our findings uncover a major molecular mechanism that underpins the formation of petal color patterns and provide a foundation for the breeding of plants with green flowers.
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Affiliation(s)
- Xinhui Zheng
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Jingqiu Lan
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Hao Yu
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Jingzhe Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Yi Zhang
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Yongmei Qin
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Xiao-Dong Su
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China
| | - Genji Qin
- State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, Beijing 100871, People's Republic of China.
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Takita E, Yoshida K, Hanano S, Shinmyo A, Shibata D. Development of the binary vector pTACAtg1 for stable gene expression in plant: Reduction of gene silencing in transgenic plants carrying the target gene with long flanking sequences. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2021; 38:391-400. [PMID: 35087303 PMCID: PMC8761585 DOI: 10.5511/plantbiotechnology.21.0823a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/23/2021] [Indexed: 06/14/2023]
Abstract
Genetic modification in plants helps us to understand molecular mechanisms underlying on plant fitness and to improve profitable crops. However, in transgenic plants, the value of gene expression often varies among plant populations of distinct lines and among generations of identical individuals. This variation is caused by several reasons, such as differences in the chromosome position, repeated sequences, and copy number of the inserted transgene. Developing a state-of-art technology to avoid the variation of gene expression levels including gene silencing has been awaited. Here, we developed a novel binary plasmid (pTACAtg1) that is based on a transformation-competent artificial chromosome (TAC) vector, harboring long genomic DNA fragments on both sides of the cloning sites. As a case study, we cloned the cauliflower mosaic virus 35S promoter:β-glucuronidase (35S:GUS) gene cassettes into the pTACAtg1, and introduced it with long flanking sequences on the pTACAtg1 into the plants. In isolated transgenic plants, the copy number was reduced and the GUS expressions were detected more stably than those in the control plants carrying the insert without flanking regions. In our result, the reduced copy number of a transgene suppressed variation and silencing of its gene expression. The pTACAtg1 vector will be suitable for the production of stable transformants and for expression analyses of a transgene.
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Affiliation(s)
- Eiji Takita
- Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan
- Research Association for Biotechnology, Nishishinbashi Yasuda Union Bldg., 2-4-2 Nishi-shinbashi, Minato-ku, Tokyo 105-0003, Japan
- Graduate School of Biological Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Kazuya Yoshida
- Graduate School of Biological Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Shigeru Hanano
- Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan
- The Kisarazu Laboratory, Graduate School of Life Sciences, Tohoku University, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan
| | - Atsuhiko Shinmyo
- Graduate School of Biological Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Daisuke Shibata
- Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan
- The Kisarazu Laboratory, Graduate School of Life Sciences, Tohoku University, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan
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