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Yang J, Zhang G, An J, Li Q, Chen Y, Zhao X, Wu J, Wang Y, Hao Q, Wang W, Wang W. Expansin gene TaEXPA2 positively regulates drought tolerance in transgenic wheat (Triticum aestivum L.). PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2020; 298:110596. [PMID: 32771153 DOI: 10.1016/j.plantsci.2020.110596] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 07/03/2020] [Accepted: 07/05/2020] [Indexed: 05/08/2023]
Abstract
Expansins loosen plant cell walls and are involved in cell enlargement and various abiotic stresses. In previous studies, we cloned the expansin gene TaEXPA2 from the wheat cultivar HF9703. Here, we studied its function and regulation in wheat drought stress tolerance. The results indicated that TaEXPA2-overexpressing wheat plants (OE) exhibited drought tolerant phenotypes, whereas down-regulation of TaEXPA2 by RNA interference (RNAi) resulted in elevated drought sensitivity, as measured by survival rate, photosynthetic rate and water containing ability under drought stress. Overexpression of TaEXPA2 enhanced the antioxidant capacity in wheat plants, via elevation of antioxidant enzyme activity and the increase of the transcripts of some ROS scavenging enzyme-related genes. Further investigation revealed that TaEXPA2 positively influenced lateral root formation under drought conditions. A MYB transcription factor of wheat named TaMPS activates TaEXPA2 expression directly by binding to its promoter. Overexpression of TaMPS in Arabidopsis conferred drought tolerance associated with improved lateral root number, and the close homolog genes of TaEXPA2 were up-regulated in Arabidopsis roots overexpressing TaMPS, which suggest that TaMPS may function as one of the regulator of TaEXPA2 gene expression in the root lateral development under drought stress. These findings suggest that TaEXPA2 positively regulates drought stress tolerance in wheat.
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Affiliation(s)
- Junjiao Yang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Guangqiang Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Jie An
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Qinxue Li
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Yanhui Chen
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China; Research Institute of Pomology of Chinese Academy of Agricultural Sciences, Xingcheng 125100, Liaoning, China
| | - Xiaoyu Zhao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Jiajie Wu
- State Key Laboratory of Crop Biology, College of Agronomy, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Yong Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China
| | - Qunqun Hao
- College of Life Sciences, Zaozhuang University, Zaozhuang 277160, Shandong, China
| | - Wenqiang Wang
- College of Life Sciences, Zaozhuang University, Zaozhuang 277160, Shandong, China.
| | - Wei Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an 271018, Shandong, China.
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The Role of Chloroplast Gene Expression in Plant Responses to Environmental Stress. Int J Mol Sci 2020; 21:ijms21176082. [PMID: 32846932 PMCID: PMC7503970 DOI: 10.3390/ijms21176082] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/16/2022] Open
Abstract
Chloroplasts are plant organelles that carry out photosynthesis, produce various metabolites, and sense changes in the external environment. Given their endosymbiotic origin, chloroplasts have retained independent genomes and gene-expression machinery. Most genes from the prokaryotic ancestors of chloroplasts were transferred into the nucleus over the course of evolution. However, the importance of chloroplast gene expression in environmental stress responses have recently become more apparent. Here, we discuss the emerging roles of the distinct chloroplast gene expression processes in plant responses to environmental stresses. For example, the transcription and translation of psbA play an important role in high-light stress responses. A better understanding of the connection between chloroplast gene expression and environmental stress responses is crucial for breeding stress-tolerant crops better able to cope with the rapidly changing environment.
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Li YT, Li Y, Li YN, Liang Y, Sun Q, Li G, Liu P, Zhang ZS, Gao HY. Dynamic light caused less photosynthetic suppression, rather than more, under nitrogen deficit conditions than under sufficient nitrogen supply conditions in soybean. BMC PLANT BIOLOGY 2020; 20:339. [PMID: 32680459 PMCID: PMC7368695 DOI: 10.1186/s12870-020-02516-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Accepted: 06/23/2020] [Indexed: 05/23/2023]
Abstract
BACKGROUND Plants are always exposed to dynamic light. The photosynthetic light use efficiency of leaves is lower in dynamic light than in uniform irradiance. Research on the influence of environmental factors on dynamic photosynthesis is very limited. Nitrogen is critical for plants, especially for photosynthesis. Low nitrogen (LN) decreases ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and thus limits photosynthesis. The decrease in Rubisco also delays photosynthetic induction in LN leaves; therefore, we hypothesized that the difference of photosynthetic CO2 fixation between uniform and dynamic light will be greater in LN leaves compared to leaves with sufficient nitrogen supply. RESULTS To test this hypothesis, soybean plants were grown under low or high nitrogen (HN), and the photosynthetic gas exchange, enzyme activity and protein amount in leaves were measured under uniform and dynamic light. Unexpectedly, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves. The underlying mechanism was also clarified. Short low-light (LL) intervals did not affect Rubisco activity but clearly deactivated fructose-1,6-bisphosphatase (FBPase) and sedoheptulose-1,7-bisphosphatase (SBPase), indicating that photosynthetic induction after a LL interval depends on the reactivation of FBPase and SBPase rather than Rubisco. In LN leaves, the amount of Rubisco decreased more than FBPase and SBPase, so FBPase and SBPase were present in relative excess. A lower fraction of FBPase and SBPase needs to be activated in LN leaves for photosynthesis recovery during the high-light phase of dynamic light. Therefore, photosynthetic recovery is faster in LN leaves than in HN leaves, which relieves the photosynthetic suppression caused by dynamic light in LN leaves. CONCLUSIONS Contrary to our expectations, dynamic light caused less photosynthetic suppression, rather than more, in LN leaves than in HN leaves of soybean. This is the first report of a stress condition alleviating the photosynthetic suppression caused by dynamic light.
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Affiliation(s)
- Yu-Ting Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Ying Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Yue-Nan Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Ying Liang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
| | - Qiang Sun
- Tai'an Testing Center For Food And Drug Control, Tai'an, Shandong Province, China
| | - Geng Li
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Peng Liu
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Agronomy, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Zi-Shan Zhang
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China.
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China.
| | - Hui-Yuan Gao
- State Key Lab of Crop Biology, Tai'an, Shandong Province, China
- College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong Province, China
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Zhuang K, Wang J, Jiao B, Chen C, Zhang J, Ma N, Meng Q. WHIRLY1 maintains leaf photosynthetic capacity in tomato by regulating the expression of RbcS1 under chilling stress. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:3653-3663. [PMID: 32189001 DOI: 10.1093/jxb/eraa145] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/17/2020] [Indexed: 06/10/2023]
Abstract
Rubisco, which consists of eight large subunits (RBCLs) and eight small subunits (RBCSs), is a major photosynthetic enzyme that is sensitive to chilling stress. However, it is largely unclear how plants maintain high Rubisco content under low temperature conditions. Here, we report that tomato WHIRLY1 (SlWHY1) positively regulates the Rubisco level under chilling stress by directly binding to the promoter region of SlRbcS1, resulting in the activation of SlRbcS1 expression. SlRbcS1-overexpressing lines had higher Rubisco contents and were more resistant to chilling stress compared with the wild type. Quantitative real-time PCR analyses showed that, among the five RbcS genes, only SlRbcS1 expression is up-regulated by chilling treatment. These results indicate that SlWHIRLY1 specifically enhances the levels of SlRbcS1 and confers tolerance to chilling stress. The amino acid sequence of SlRBCS1 shows 92.67% identity with those of another two RBCS proteins and three residues are specifically found in SlRBCS1. However, mutation of these residues to alanine in SlRBCS1 does not influence its function during cold adaptation. Thus, we conclude that high levels of Rubisco, but not the specific residues in SlRBCS1, play important roles in tolerance to chilling stress in tomato.
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Affiliation(s)
- Kunyang Zhuang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
| | - Jieyu Wang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
| | - Baozhen Jiao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
| | - Chong Chen
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
| | - Junjie Zhang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
| | - Nana Ma
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
| | - Qingwei Meng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai' an, Shandong, China
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Zhuang K, Gao Y, Liu Z, Diao P, Sui N, Meng Q, Meng C, Kong F. WHIRLY1 Regulates HSP21.5A Expression to Promote Thermotolerance in Tomato. PLANT & CELL PHYSIOLOGY 2020; 61:169-177. [PMID: 31596474 DOI: 10.1093/pcp/pcz189] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 09/26/2019] [Indexed: 05/25/2023]
Abstract
Heat stress poses a major threat to plant productivity and crop yields. The induction of heat shock proteins (HSPs) by heat shock factors is a principal defense response of plants exposed to heat stress. In this study, we identified and analyzed the heat stress-induced Whirly1 (SlWHY1) gene in tomato (Solanum lycopersicum). We generated various SlWHY1-overexpressing (OE) and SlWHY1-RNA interference (RNAi) lines to investigate the role of WHIRLY1 in thermotolerance. Compared with the wild type (WT), the OE lines showed less wilting, as reflected by their increased membrane stability and soluble sugar content and reduced reactive oxygen species (ROS) accumulation under heat stress. By contrast, RNAi lines with inhibited SlWHY1 expression showed the opposite phenotype and corresponding physiological indices under heat stress. The heat-induced gene SlHSP21.5A, encoding an endoplasmic reticulum-localized HSP, was upregulated in the OE lines and downregulated in the RNAi lines compared with the WT. RNAi-mediated inhibition of SlHSP21.5A expression also resulted in reduced membrane stability and soluble sugar content and increased ROS accumulation under heat stress compared with the WT. SlWHY1 binds to the elicitor response element-like element in the promoter of SlHSP21.5A to activate its transcription. These findings suggest that SlWHY1 promotes thermotolerance in tomato by regulating SlHSP21.5A expression.
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Affiliation(s)
- Kunyang Zhuang
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Yangyang Gao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Zhuangbin Liu
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Pengfei Diao
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Na Sui
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Qingwei Meng
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, China
| | - Chen Meng
- Marine Agriculture Research Center, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Fanying Kong
- State Key Laboratory of Crop Biology, College of Life Sciences, Shandong Agricultural University, Tai'an, Shandong 271018, China
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Lin W, Huang D, Shi X, Deng B, Ren Y, Lin W, Miao Y. H 2O 2 as a Feedback Signal on Dual-Located WHIRLY1 Associates with Leaf Senescence in Arabidopsis. Cells 2019; 8:cells8121585. [PMID: 31817716 PMCID: PMC6952816 DOI: 10.3390/cells8121585] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 11/21/2019] [Accepted: 12/04/2019] [Indexed: 12/31/2022] Open
Abstract
Leaf senescence, either as a natural stage of development or as an induced process under stress conditions, incorporates multiple intricate signaling pathways. At the cellular level, retrograde signals have been considered as important players during the initiation and progression of senescence in both animals and plants. The plant-specific single-strand DNA-binding protein WHIRLY1 (WHY1), a repressor of leaf natural senescence, is dually located in both nucleus and plastids. Despite many years of studies, the myth about its dual location and the underlying functional implications remain elusive. Here, we provide further evidence in Arabidopsis showing that alteration in WHY1 allocation between the nucleus and chloroplast causes perturbation in H2O2 homeostasis, resulting in adverse plant senescence phenotypes. The knockout of WHY1 increased H2O2 content at 37 days post-germination, coincident with an early leaf senescence phenotype, which can be rescued by ectopic expression of the nuclear isoform (nWHY1), but not by the plastid isoform (pWHY1). Instead, accumulated pWHY1 greatly provoked H2O2 in cells. On the other hand, exogenous H2O2 treatment induced a substantial plastid accumulation of WHY1 proteins and at the same time reduced the nuclear isoforms. This H2O2-induced loss of nucleus WHY1 isoform was accompanied by enhanced enrichments of histone H3 lysine 9 acetylation (H3K9ac) and recruitment of RNA polymerase II (RNAP II) globally, and specifically at the promoter of the senescence-related transcription factor WRKY53, which in turn activated WRKY53 transcription and led to a senescence phenotype. Thus, the distribution of WHY1 organelle isoforms and the feedback of H2O2 intervene in a circularly integrated regulatory network during plant senescence in Arabidopsis.
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Affiliation(s)
| | | | | | | | | | | | - Ying Miao
- Correspondence: ; Tel.: +86-0591-86392987
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Shi Y, Cai Z, Li D, Lu J, Ye J, Liang Y, Zheng X. Effect of Freezing on Photosystem II and Assessment of Freezing Tolerance of Tea Cultivar. PLANTS 2019; 8:plants8100434. [PMID: 31652528 PMCID: PMC6843692 DOI: 10.3390/plants8100434] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 11/23/2022]
Abstract
Freezing tolerant tea cultivars are urgently needed. The tea cultivars with highly freezing tolerance showed resistance to freezing stress induced photoinhibition. Freezing sensitivity index (H) of 47 tea clonal cultivars was investigated after severe freezing winter in 2016. To develop instrumental methods for freezing tolerance selection, the maximum photochemical efficiency of photosystem II (PSII) (Fv/Fm) and leaf color indicator a on the Hunter color scale were determined on control group (non-frozen) and frozen group (being frozen at −15 °C for 2 h and then stood at 20 °C for 5 h) of the cultivars. When the two indicators were expressed as the ratios (RFv/Fm and Ra) of frozen group to control group, linear regression of the freezing sensitivity index (H) upon the RFv/Fm and Ra produced significant relationship respectively, i.e., H = 60.31 − 50.09 RFv/Fm (p < 0.01) and H = 30.03 − 10.82 Ra (p < 0.01). Expression of gene psbA encoding D1 protein and gene psbD encoding D2 protein in PSII showed that the frezzing tolerant tea cultivars maintained a high expression level of psbA after freezing stress, which is considered to be beneficial to de novo synthesis of D1 protein and sustaining PSII activity. These findings can provide instrumental tools for assessing freezing tolerance of tea cultivars in tea breeding program.
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Affiliation(s)
- Yunlong Shi
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
| | - Zhuoyu Cai
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
| | - Da Li
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
| | - Jianliang Lu
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
| | - Jianhui Ye
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
| | - Yuerong Liang
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
| | - Xinqiang Zheng
- Tea Research Institute, Zhejiang University, Hangzhou 310058, China.
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Liu X, Zhou Y, Xiao J, Bao F. Effects of Chilling on the Structure, Function and Development of Chloroplasts. FRONTIERS IN PLANT SCIENCE 2018; 9:1715. [PMID: 30524465 PMCID: PMC6262076 DOI: 10.3389/fpls.2018.01715] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/05/2018] [Indexed: 05/18/2023]
Abstract
Chloroplasts are the organelles that perform energy transformation in plants. The normal physiological functions of chloroplasts are essential for plant growth and development. Chilling is a common environmental stress in nature that can directly affect the physiological functions of chloroplasts. First, chilling can change the lipid membrane state and enzyme activities in chloroplasts. Then, the efficiency of photosynthesis declines, and excess reactive oxygen species (ROS) are produced. On one hand, excess ROS can damage the chloroplast lipid membrane; on the other hand, ROS also represent a stress signal that can alter gene expression in both the chloroplast and nucleus to help regenerate damaged proteins, regulate lipid homeostasis, and promote plant adaptation to low temperatures. Furthermore, plants assume abnormal morphology, including chlorosis and growth retardation, with some even exhibiting severe necrosis under chilling stress. Here, we review the response of chloroplasts to low temperatures and focus on photosynthesis, redox regulation, lipid homeostasis, and chloroplast development to elucidate the processes involved in plant responses and adaptation to chilling stress.
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Affiliation(s)
- Xiaomin Liu
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Yunlin Zhou
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Jianwei Xiao
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing, China
| | - Fei Bao
- Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment, Engineering Research Center of Landscape Environment of Ministry of Education, Key Laboratory of Genetics and Breeding in Forest Trees and Ornamental Plants of Ministry of Education, School of Landscape Architecture, Beijing Forestry University, Beijing, China
- *Correspondence: Fei Bao,
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