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Cao C, Guo S, Deng P, Yang S, Xu J, Hu T, Hu Z, Chen D, Zhang H, Navea IP, Chin JH, Zhang W, Jing W. The BEL1-like homeodomain protein OsBLH4 regulates rice plant height, grain number, and heading date by repressing the expression of OsGA2ox1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2024; 119:1369-1385. [PMID: 38824648 DOI: 10.1111/tpj.16857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 05/10/2024] [Accepted: 05/14/2024] [Indexed: 06/04/2024]
Abstract
Gibberellins (GAs) play crucial roles in regulating plant architecture and grain yield of crops. In rice, the inactivation of endogenous bioactive GAs and their precursors by GA 2-oxidases (GA2oxs) regulates stem elongation and reproductive development. However, the regulatory mechanisms of GA2ox gene expression, especially in rice reproductive organs, are unknown. The BEL1-like homeodomain protein OsBLH4, a negative regulatory factor for the rice OsGA2ox1 gene, was identified in this study. Loss of OsBLH4 function results in decreased bioactive GA levels and pleiotropic phenotypes, including reduced plant height, decreased grain number per panicle, and delayed heading date, as also observed in OsGA2ox1-overexpressing plants. Consistent with the mutant phenotype, OsBLH4 was predominantly expressed in shoots and young spikelets; its encoded protein was exclusively localized in the nucleus. Molecular analysis demonstrated that OsBLH4 directly bound to the promoter region of OsGA2ox1 to repress its expression. Genetic assays revealed that OsBLH4 acts upstream of OsGA2ox1 to control rice plant height, grain number, and heading date. Taken together, these results indicate a crucial role for OsBLH4 in regulating rice plant architecture and yield potential via regulation of bioactive GA levels, and provide a potential strategy for genetic improvements of rice.
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Affiliation(s)
- Chengjuan Cao
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shuaiqiang Guo
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Ping Deng
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
- Xianghu Laboratory, Hangzhou, China
| | - Shiyi Yang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Jing Xu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Tengfei Hu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhijuan Hu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Di Chen
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Hongsheng Zhang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Ian Paul Navea
- Department of Integrative Biological Sciences and Industry, Sejong University, Seoul, Korea
| | - Joong Hyoun Chin
- Department of Integrative Biological Sciences and Industry, Sejong University, Seoul, Korea
| | - Wenhua Zhang
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Wen Jing
- National Key Laboratory of Crop Genetics and Germplasm Enhancement and Utilization, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
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Jia T, Wang H, Cui S, Li Z, Shen Y, Li H, Xiao G. Cotton BLH1 and KNOX6 antagonistically modulate fiber elongation via regulation of linolenic acid biosynthesis. PLANT COMMUNICATIONS 2024; 5:100887. [PMID: 38532644 PMCID: PMC11287173 DOI: 10.1016/j.xplc.2024.100887] [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: 10/06/2023] [Revised: 01/19/2024] [Accepted: 03/23/2024] [Indexed: 03/28/2024]
Abstract
BEL1-LIKE HOMEODOMAIN (BLH) proteins are known to function in various plant developmental processes. However, the role of BLHs in regulating plant cell elongation is still unknown. Here, we identify a BLH gene, GhBLH1, that positively regulates fiber cell elongation. Combined transcriptomic and biochemical analyses reveal that GhBLH1 enhances linolenic acid accumulation to promote cotton fiber cell elongation by activating the transcription of GhFAD7A-1 via binding of the POX domain of GhBLH1 to the TGGA cis-element in the GhFAD7A-1 promoter. Knockout of GhFAD7A-1 in cotton significantly reduces fiber length, whereas overexpression of GhFAD7A-1 results in longer fibers. The K2 domain of GhKNOX6 directly interacts with the POX domain of GhBLH1 to form a functional heterodimer, which interferes with the transcriptional activation of GhFAD7A-1 via the POX domain of GhBLH1. Overexpression of GhKNOX6 leads to a significant reduction in cotton fiber length, whereas knockout of GhKNOX6 results in longer cotton fibers. An examination of the hybrid progeny of GhBLH1 and GhKNOX6 transgenic cotton lines provides evidence that GhKNOX6 negatively regulates GhBLH1-mediated cotton fiber elongation. Our results show that the interplay between GhBLH1 and GhKNOX6 modulates regulation of linolenic acid synthesis and thus contributes to plant cell elongation.
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Affiliation(s)
- Tingting Jia
- College of Life Sciences, Shihezi University, Shihezi 832003, China
| | - Huiqin Wang
- College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Shiyan Cui
- Zhengzhou Research Base, State Key Laboratory of Cotton Biology, School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Zihan Li
- Geosystems Research Institute, Mississippi State University, Starkville, MS 39762, USA
| | - Yongcui Shen
- College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China
| | - Hongbin Li
- College of Life Sciences, Shihezi University, Shihezi 832003, China.
| | - Guanghui Xiao
- College of Life Sciences, Shaanxi Normal University, Xi'an 710062, China.
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Current Advances and Future Prospects for Molecular Research for Agronomically Important Traits in Rice. Int J Mol Sci 2022; 23:ijms23147531. [PMID: 35886876 PMCID: PMC9316905 DOI: 10.3390/ijms23147531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/02/2022] [Accepted: 07/05/2022] [Indexed: 02/04/2023] Open
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Niu X, Fu D. The Roles of BLH Transcription Factors in Plant Development and Environmental Response. Int J Mol Sci 2022; 23:3731. [PMID: 35409091 PMCID: PMC8998993 DOI: 10.3390/ijms23073731] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 03/16/2022] [Accepted: 03/22/2022] [Indexed: 02/04/2023] Open
Abstract
Despite recent advancements in plant molecular biology and biotechnology, providing enough, and safe, food for an increasing world population remains a challenge. The research into plant development and environmental adaptability has attracted more and more attention from various countries. The transcription of some genes, regulated by transcript factors (TFs), and their response to biological and abiotic stresses, are activated or inhibited during plant development; examples include, rooting, flowering, fruit ripening, drought, flooding, high temperature, pathogen infection, etc. Therefore, the screening and characterization of transcription factors have increasingly become a hot topic in the field of plant research. BLH/BELL (BEL1-like homeodomain) transcription factors belong to a subfamily of the TALE (three-amino-acid-loop-extension) superfamily and its members are involved in the regulation of many vital biological processes, during plant development and environmental response. This review focuses on the advances in our understanding of the function of BLH/BELL TFs in different plants and their involvement in the development of meristems, flower, fruit, plant morphogenesis, plant cell wall structure, the response to the environment, including light and plant resistance to stress, biosynthesis and signaling of ABA (Abscisic acid), IAA (Indoleacetic acid), GA (Gibberellic Acid) and JA (Jasmonic Acid). We discuss the theoretical basis and potential regulatory models for BLH/BELL TFs' action and provide a comprehensive view of their multiple roles in modulating different aspects of plant development and response to environmental stress and phytohormones. We also present the value of BLHs in the molecular breeding of improved crop varieties and the future research direction of the BLH gene family.
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Affiliation(s)
| | - Daqi Fu
- The College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China;
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