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Ding F, Li F, Zhang B. A plastid-targeted heat shock cognate 70-kDa protein confers osmotic stress tolerance by enhancing ROS scavenging capability. FRONTIERS IN PLANT SCIENCE 2022; 13:1012145. [PMID: 36275553 PMCID: PMC9581120 DOI: 10.3389/fpls.2022.1012145] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/12/2022] [Indexed: 06/12/2023]
Abstract
Osmotic stress severely affects plant growth and development, resulting in massive loss of crop quality and quantity worldwide. The 70-kDa heat shock proteins (HSP70s) are highly conserved molecular chaperones that play essential roles in cellular processes including abiotic stress responses. However, whether and how plastid-targeted heat shock cognate 70 kDa protein (cpHSC70-1) participates in plant osmotic stress response remain elusive. Here, we report that the expression of cpHSC70-1 is significantly induced upon osmotic stress treatment. Phenotypic analyses reveal that the plants with cpHSC70-1 deficiency are sensitive to osmotic stress and the plants overexpressing cpHSC70-1 exhibit enhanced tolerance to osmotic stress. Consistently, the expression of the stress-responsive genes is lower in cphsc70-1 mutant but higher in 35S:: cpHSC70-1 lines than that in wild-type plants when challenged with osmotic stress. Further, the cphsc70-1 plants have less APX and SOD activity, and thus more ROS accumulation than the wild type when treated with mannitol, but the opposite is observed in the overexpression lines. Overall, our data reveal that cpHSC70-1 is induced and functions positively in plant response to osmotic stress by promoting the expression of the stress-responsive genes and reducing ROS accumulation.
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Affiliation(s)
- Feng Ding
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
- School of Landscape and Ecological Engineering, Hebei University of Engineering, Handan, China
| | - Fan Li
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Binglei Zhang
- School of Landscape and Ecological Engineering, Hebei University of Engineering, Handan, China
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Zhao D, Zheng Y, Yang L, Yao Z, Cheng J, Zhang F, Jiang H, Liu D. The transcription factor AtGLK1 acts upstream of MYBL2 to genetically regulate sucrose-induced anthocyanin biosynthesis in Arabidopsis. BMC PLANT BIOLOGY 2021; 21:242. [PMID: 34049482 PMCID: PMC8162001 DOI: 10.1186/s12870-021-03033-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/11/2021] [Indexed: 05/12/2023]
Abstract
BACKGROUND The regulation of anthocyanin biosynthesis by various factors including sugars, light and abiotic stresses is mediated by numerous regulatory factors acting at the transcriptional level. Here experimental evidence was provided in order to demonstrate that the nuclear GARP transcription factor AtGLK1 plays an important role in regulating sucrose-induced anthocyanin biosynthesis in Arabidopsis. RESULTS The results obtained using real-time quantitative PCR and GUS staining assays revealed that AtGLK1 was mainly expressed in the green tissues of Arabidopsis seedlings and could be induced by sucrose. The loss-of-function glk1 glk2 double mutant has lower anthocyanin levels than the glk2 single mutant, although it has been determined that loss of AtGLK1 alone does not affect anthocyanin accumulation. Overexpression of AtGLK1 enhances the accumulation of anthocyanin in transgenic Arabidopsis seedlings accompanied by increased expression of anthocyanin biosynthetic and regulatory genes. Moreover, we found that AtGLK1 also participates in plastid-signaling mediated anthocyanin accumulations. Genetic, physiological, and molecular biological approaches demonstrated that AtGLK1 acts upstream of MYBL2, which is a key negative regulator of anthocyanin biosynthesis, to genetically regulate sucrose-induced anthocyanin biosynthesis. CONCLUSION Our results indicated that AtGLK1 positively regulates sucrose-induced anthocyanin biosynthesis in Arabidopsis via MYBL2.
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Affiliation(s)
- Dongming Zhao
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Yuxuan Zheng
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Lingjun Yang
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Ziyu Yao
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Jianfeng Cheng
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Fang Zhang
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Haiyan Jiang
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Dong Liu
- College of Agronomy/Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Jiangxi Agricultural University, Nanchang, 330045, China.
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Kakan X, Yu Y, Li S, Li X, Huang R, Wang J. Ascorbic acid modulation by ABI4 transcriptional repression of VTC2 in the salt tolerance of Arabidopsis. BMC PLANT BIOLOGY 2021; 21:112. [PMID: 33627094 PMCID: PMC7905542 DOI: 10.1186/s12870-021-02882-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 01/20/2021] [Indexed: 05/14/2023]
Abstract
BACKGROUND Abscisic acid (ABA) plays an important role in plant abiotic stress responses, and ABA INSENSITIVE 4 (ABI4) is a pivotal transcription factor in the ABA signaling pathway. In Arabidopsis, ABI4 negatively regulates salt tolerance; however, the mechanism through which ABI4 regulates plant salt tolerance is poorly understood. Our previous study showed that ABI4 directly binds to the promoter of the VITAMIN C DEFECTIVE 2 (VTC2) gene, inhibiting the transcription of VTC2 and ascorbic acid (AsA) biosynthesis. RESULTS In the present study, we found that treatment with exogenous AsA could alleviate salt stress sensitivity of ABI4-overexpressing transgenic plants. The decreased AsA content and increased reactive oxygen species (ROS) levels in ABI4-overexpressing seedlings under salt treatment indicated that AsA-promoted ROS scavenging was related to ABI4-mediated salt tolerance. Gene expression analysis showed that ABI4 was induced at the early stage of salt stress, giving rise to reduced VTC2 expression. Accordingly, the abundance of the VTC2 protein decreased under the same salt stress conditions, and was absent in the ABI4 loss-of-function mutants, suggesting that the transcriptional inhibition of ABI4 on VTC2 resulted in the attenuation of VTC2 function. In addition, other encoding genes in the AsA biosynthesis and recycling pathways showed different responses to salt stress, demonstrating that AsA homeostasis is complicated under salinity stress. CONCLUSIONS This study elucidates the negative modulation of ABI4 in salt stress tolerance through the regulation of AsA biosynthesis and ROS accumulation in plants.
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Affiliation(s)
- Xiamusiya Kakan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- College of Agronomy, Xinjiang Agricultural University, Urumchi, 830052, China
| | - Yanwen Yu
- College of Agronomy, Henan Agricultural University, Zhengzhou, 450002, China
| | - Shenghui Li
- College of Landscape and Ecological Engineering, Hebei University of Engineering, Handan, 056038, China
| | - Xiaoying Li
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - Rongfeng Huang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
- China National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing, 100081, China
| | - Juan Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
- China National Key Facility of Crop Gene Resources and Genetic Improvement, Beijing, 100081, China.
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Chandrasekaran U, Luo X, Zhou W, Shu K. Multifaceted Signaling Networks Mediated by Abscisic Acid Insensitive 4. PLANT COMMUNICATIONS 2020; 1:100040. [PMID: 33367237 PMCID: PMC7748004 DOI: 10.1016/j.xplc.2020.100040] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 12/24/2019] [Accepted: 03/04/2020] [Indexed: 05/04/2023]
Abstract
Although ABSCISIC ACID INSENSITIVE 4 (ABI4) was initially demonstrated as a key positive regulator in the phytohormone abscisic acid (ABA) signaling cascade, multiple studies have now shown that it is actually involved in the regulation of several other cascades, including diverse phytohormone biogenesis and signaling pathways, various developmental processes (such as seed dormancy and germination, seedling establishment, and root development), disease resistance and lipid metabolism. Consistent with its versatile biological functions, ABI4 either activates or represses transcription of its target genes. The upstream regulators of ABI4 at both the transcription and post-transcription levels have also been documented in recent years. Consequently, a complicated network consisting of the direct target genes and upstream regulators of ABI4, through which ABI4 participates in several phytohormone crosstalk networks, has been generated. In this review, we summarize current understanding of the sophisticated ABI4-mediated molecular networks, mainly focusing on diverse phytohormone (including ABA, gibberellin, cytokinin, ethylene, auxin, and jasmonic acid) crosstalks. We also discuss the potential mechanisms through which ABI4 receives the ABA signal, focusing on protein phosphorylation modification events.
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Affiliation(s)
| | - Xiaofeng Luo
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710012, China
- Institute of Ecological Agriculture, Sichuan Agricultural University, Chengdu 611130, China
| | - Wenguan Zhou
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710012, China
| | - Kai Shu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an 710012, China
- Corresponding author
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