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Tao X, Zhao Y, Ma L, Wu J, Zeng R, Jiao J, Li R, Ma W, Lian Y, Wang W, Pu Y, Yang G, Liu L, Li X, Sun W. Cloning and functional analysis of the BrCUC2 gene in Brassica rapa L. FRONTIERS IN PLANT SCIENCE 2023; 14:1274567. [PMID: 37965013 PMCID: PMC10642757 DOI: 10.3389/fpls.2023.1274567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/16/2023] [Indexed: 11/16/2023]
Abstract
The CUP-SHAPED COTYLEDON2 (CUC2) gene plays an important role in the formation of apical meristem and organ edges in plants. The apical meristematic tissue of Brassica rapa (B. rapa) is associated with cold resistance, however, the role of the CUC2 gene in cold resistance of B.rapa is unclear. In this study, we used bioinformatics software to analyze the structure of BrCUC2 gene, real-time fluorescence quantitative PCR to detect the expression level of BrCUC2, constructed transgenic Arabidopsis thaliana by the flower dipping method and subcellular localization for functional validation. The results showed that, we isolated a 1104 bp open reading frame of BrCUC2 from the winter B. rapa cultivar 'Longyou 7'. The BrCUC2 contains a highly conserved domain belonging to the NAM superfamily. Its homologus CUC genes contain similar conserved motifs and are closely related to Brassica oleracea (B.oleracea), and the N-terminal of amino acid sequence contains NAC domain. BrCUC2 protein was localized in the nucleus and self-activation tests showed that pGBKT7-BrCUC2 had self-activation. Tissue-specific expression analysis and promoter β-Glucuronidase (GUS) activity showed that BrCUC2 had high expression levels in B. rapa growth points and A. thaliana leaf edges, stems and growth points. After low-temperature stress, BrCUC2 showed greater expression in 'Longyou 7,' which presents strong cold resistance and concave growth points, than in 'Longyou 99,' which presents weak cold resistance and protruding growth points. BrCUC2 promoter contains multiple elements related to stress responses. BrCUC2 overexpression revealed that the phenotype did not differ from that of the wild type during the seedling stage but showed weak growth and a dwarf phenotype during the flowering and mature stages. After low-temperature treatment, the physiological indexes and survival rate of BrCUC2-overexpression lines of Arabidopsis thaliana (A. thaliana) were better than those of the wild type within 12 h, although differences were not observed after 24 h. These results showed that BrCUC2 improved the low-temperature tolerance of transgenic A. thaliana within a short time. It can provide a foundation for the study of cold resistance in winter B. rapa.
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Affiliation(s)
- Xiaolei Tao
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Yuhong Zhao
- Gansu Yasheng Agricultural Research Institute Co. Ltd, Crop Office, Lanzhou, China
| | - Li Ma
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Junyan Wu
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Rui Zeng
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - JinTang Jiao
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Rong Li
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Weiming Ma
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Yintao Lian
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Wangtian Wang
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Yuanyuan Pu
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Gang Yang
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Lijun Liu
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Xuecai Li
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
| | - Wancang Sun
- State Key Laboratory of Aridland Crop Science, College of Agronomy, Gansu Agricultural University, Lanzhou, China
- Gansu Key Laboratory of Crop Genetic Improvement and Germplasm Innovation, Gansu Agricultural University, Lanzhou, China
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Li M, Pan X, Li H. RD29A promoter constitutively drives a rice Hd3a expression to promote early-flowering in Saussurea involucrate Kar. et Kir. ex Maxim. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 195:155-162. [PMID: 36638605 DOI: 10.1016/j.plaphy.2023.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 01/04/2023] [Accepted: 01/07/2023] [Indexed: 06/17/2023]
Abstract
S. involucratae, an endemic and endangered plant, is a valuable and traditional Chinese medicinal herb. In order to control the flowering time of S. involucratae, we used the well-known stress inducible RD29A promoter to drive Hd3a (a FT ortholog from rice) expression in S. involucratae. Unexpectedly, the majority of regenerated buds in RD29A::Hd3a transgenic lines (S-RH) produced flowers in tissue culture stage under normal growth (25 ± 2 °C) condition. Their flowering time was not further influenced by salt treatment. Hd3a in S-RH was strongly expressed in MS media supplemented with or without 50 mM NaCl. RD29A::GUS transgenic experiments further revealed that RD29A constitutively promoted GUS expression in both S. involucrate and halophyte Thellungiella halophile, in contrast to glycophic plants Oryza sativa L. 'Zhonghua 11', in which its expression was up-regulated by cold, salinity, and drought stress. The results supported the hypothesis that RD29A promoter activity is inducible in stress-sensitive plants, but constitutive in stress-tolerant ones. Importantly, S-RH plants produced pollen grains and seeds under normal conditions. Additionally, we found that OsLEA3-1::Hd3a and HSP18.2::Hd3a could not promote S. involucrate to flower under either normal conditions or abiotic stresses. Taken together, we demonstrated the potential of RD29A::Hd3a might be served as a feasible approach in breeding S. involucrate under normal condition.
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Affiliation(s)
- Meiru Li
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, Chinese Academy of Sciences, South China Botanical Garden, Guangzhou, 510650, People's Republic of China.
| | - Xiaoping Pan
- Key Laboratory of South China Agricultural Plant Molecular Analysis and Genetic Improvement & Guangdong Provincial Key Laboratory of Applied Botany, Chinese Academy of Sciences, South China Botanical Garden, Guangzhou, 510650, People's Republic of China.
| | - Hongqing Li
- Guangdong Provincial Key Lab of Biotechnology for Plant Development, South China Normal University, Guangzhou, 510631, People's Republic of China.
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