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Yuan G, Nong T, Hunpatin OS, Shi C, Su X, Wang Q, Liu H, Dai P, Ning Y. Research Progress on Plant Shaker K + Channels. PLANTS (BASEL, SWITZERLAND) 2024; 13:1423. [PMID: 38794493 PMCID: PMC11125005 DOI: 10.3390/plants13101423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/16/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024]
Abstract
Plant growth and development are driven by intricate processes, with the cell membrane serving as a crucial interface between cells and their external environment. Maintaining balance and signal transduction across the cell membrane is essential for cellular stability and a host of life processes. Ion channels play a critical role in regulating intracellular ion concentrations and potentials. Among these, K+ channels on plant cell membranes are of paramount importance. The research of Shaker K+ channels has become a paradigm in the study of plant ion channels. This study offers a comprehensive overview of advancements in Shaker K+ channels, including insights into protein structure, function, regulatory mechanisms, and research techniques. Investigating Shaker K+ channels has enhanced our understanding of the regulatory mechanisms governing ion absorption and transport in plant cells. This knowledge offers invaluable guidance for enhancing crop yields and improving resistance to environmental stressors. Moreover, an extensive review of research methodologies in Shaker K+ channel studies provides essential reference solutions for researchers, promoting further advancements in ion channel research.
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Affiliation(s)
- Guang Yuan
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Tongjia Nong
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Oluwaseyi Setonji Hunpatin
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Chuhan Shi
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaoqing Su
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
- Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Qian Wang
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Haobao Liu
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Peigang Dai
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
| | - Yang Ning
- Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao 266101, China
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2
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Blatt MR. A charged existence: A century of transmembrane ion transport in plants. PLANT PHYSIOLOGY 2024; 195:79-110. [PMID: 38163639 PMCID: PMC11060664 DOI: 10.1093/plphys/kiad630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/01/2023] [Indexed: 01/03/2024]
Abstract
If the past century marked the birth of membrane transport as a focus for research in plants, the past 50 years has seen the field mature from arcane interest to a central pillar of plant physiology. Ion transport across plant membranes accounts for roughly 30% of the metabolic energy consumed by a plant cell, and it underpins virtually every aspect of plant biology, from mineral nutrition, cell expansion, and development to auxin polarity, fertilization, plant pathogen defense, and senescence. The means to quantify ion flux through individual transporters, even single channel proteins, became widely available as voltage clamp methods expanded from giant algal cells to the fungus Neurospora crassa in the 1970s and the cells of angiosperms in the 1980s. Here, I touch briefly on some key aspects of the development of modern electrophysiology with a focus on the guard cells of stomata, now without dispute the premier plant cell model for ion transport and its regulation. Guard cells have proven to be a crucible for many technical and conceptual developments that have since emerged into the mainstream of plant science. Their study continues to provide fundamental insights and carries much importance for the global challenges that face us today.
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Affiliation(s)
- Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow G12 8QQ, UK
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3
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Lian W, Geng A, Wang Y, Liu M, Zhang Y, Wang X, Chen G. The Molecular Mechanism of Potassium Absorption, Transport, and Utilization in Rice. Int J Mol Sci 2023; 24:16682. [PMID: 38069005 PMCID: PMC10705939 DOI: 10.3390/ijms242316682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/18/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
Potassium is essential for plant growth and development and stress adaptation. The maintenance of potassium homeostasis involves a series of potassium channels and transporters, which promote the movement of potassium ions (K+) across cell membranes and exhibit complex expression patterns and regulatory mechanisms. Rice is a major food crop in China. The low utilization rate of potassium fertilizer limits the yield and quality of rice. Elucidating the molecular mechanisms of potassium absorption, transport, and utilization is critical in improving potassium utilization efficiency in rice. Although some K+ transporter genes have been identified from rice, research on the regulatory network is still in its infancy. Therefore, this review summarizes the relevant information on K+ channels and transporters in rice, covering the absorption of K+ in the roots, transport to the shoots, the regulation pathways, the relationship between K+ and the salt tolerance of rice, and the synergistic regulation of potassium, nitrogen, and phosphorus signals. The related research on rice potassium nutrition has been comprehensively reviewed, the existing research foundation and the bottleneck problems to be solved in this field have been clarified, and the follow-up key research directions have been pointed out to provide a theoretical framework for the cultivation of potassium-efficient rice.
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Affiliation(s)
- Wenli Lian
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
| | - Anjing Geng
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
| | - Yihan Wang
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
| | - Minghao Liu
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
| | - Yue Zhang
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
| | - Xu Wang
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
| | - Guang Chen
- Institute of Quality Standard and Monitoring Technology for Agro-Products of Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China
- Key Laboratory of Testing and Evaluation for Agro-Product Safety and Quality, Ministry of Agriculture and Rural Affairs, Guangzhou 510640, China
- Guangdong Provincial Key Laboratory of Quality & Safety Risk Assessment for Agro-Products, Guangzhou 510640, China
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4
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Wang Q, Li S, Li F, Tian X, Li Z. Identification of Shaker Potassium Channel Family Members in Gossypium hirsutum L. and Characterization of GhKAT1aD. Life (Basel) 2023; 13:1461. [PMID: 37511836 PMCID: PMC10381577 DOI: 10.3390/life13071461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 07/30/2023] Open
Abstract
K+ channels of the Shaker family have been shown to play crucial roles in K+ uptake and transport. Cotton (Gossypium hirsutum) is an important cash crop. In this study, the 24 Shaker family genes were identified in cotton. Phylogenetic analysis suggests that they were assigned to five clusters. Additionally, their chromosomal location, conserved motifs and gene structure were analyzed. The promoter of cotton Shaker K+ channel genes comprises drought-, low-temperature-, phytohormone-response elements, etc. As indicated by qRT-PCR (quantitative real-time PCR), cotton Shaker K+ channel genes responded to low K+ and NaCl, and especially dehydration stress, at the transcript level. Moreover, one of the Shaker K+ channel genes, GhKAT1aD, was characterized. This gene is localized in the plasma membrane and is predicted to contain six transmembrane segments. It restored the growth of the yeast mutant strain defective in K+ uptake, and silencing GhKAT1a via VIGS (virus-induced gene silencing) resulted in more severe symptoms of K+ deficiency in cotton leaves as well as a lower net K+ uptake rate. The results of this study showed the overall picture of the cotton Shaker K+ channel family regarding bioinformatics as well as the function of one of its members, which provide clues for future investigations of cotton K+ transport and molecular insights for breeding K+-efficient cotton varieties.
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Affiliation(s)
- Qianqian Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China
| | - Shuying Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China
| | - Fangjun Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China
| | - Xiaoli Tian
- State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China
| | - Zhaohu Li
- State Key Laboratory of Plant Physiology and Biochemistry, College of Agronomy and Biotechnology, China Agricultural University, No. 2 Yuanmingyuan Xi Lu, Haidian District, Beijing 100193, China
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5
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Hasan M, Liu XD, Waseem M, Guang-Qian Y, Alabdallah NM, Jahan MS, Fang XW. ABA activated SnRK2 kinases: an emerging role in plant growth and physiology. PLANT SIGNALING & BEHAVIOR 2022; 17:2071024. [PMID: 35506344 PMCID: PMC9090293 DOI: 10.1080/15592324.2022.2071024] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Members of the SNF1-related protein kinase 2 (SnRK2) family are plant-specific serine or threonine kinases that play a pivotal role in the response of plants to abiotic stresses. Members of this plant-specific kinase family have included a critical regulator (SnRK2) of abscisic acid (ABA) response in plants. Plant organ development is governed substantially by the interaction of the SnRK2 and the phytohormone abscisic acid (ABA). Recent research has revealed a synergistic link between SnRK2 and ABA signaling in a plant's response to stress such as drought and shoot growth. SnRK2 kinases play a dual role in the control of SnRK1 and the development of a plant. The dual role of SnRK2 kinases promotes plant growth under optimal conditions and in the absence of ABA while inhibiting the growth of plants in response to ABA. In this review, we have uncovered the roles of ABA-activated SnRK2 kinases in plants, as well as their physiological mechanisms.
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Affiliation(s)
- Md.Mahadi Hasan
- State Key Laboratory of Grassland Agro- College of Ecology, Lanzhou University, Lanzhou 730000, Gansu Province, China
| | - Xu-Dong Liu
- State Key Laboratory of Grassland Agro- College of Ecology, Lanzhou University, Lanzhou 730000, Gansu Province, China
| | - Muhammed Waseem
- State Key Laboratory of Grassland Agro- College of Ecology, Lanzhou University, Lanzhou 730000, Gansu Province, China
| | - Yao Guang-Qian
- State Key Laboratory of Grassland Agro- College of Ecology, Lanzhou University, Lanzhou 730000, Gansu Province, China
| | - Nadiyah M. Alabdallah
- Department of Biology, College of Science, Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia
| | - Mohammad Shah Jahan
- Department of Horticulture, Sher-e-Bangla Agricultural University, Dhaka, Bangladesh
| | - Xiang-Wen Fang
- State Key Laboratory of Grassland Agro- College of Ecology, Lanzhou University, Lanzhou 730000, Gansu Province, China
- CONTACT Xiang-Wen Fang State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou730000, Gansu Province, China
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6
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Zhou H, Hu Z, Luo Y, Feng C, Long Y. Multiple ALMT subunits combine to form functional anion channels: A case study for rice ALMT7. FRONTIERS IN PLANT SCIENCE 2022; 13:1012578. [PMID: 36452104 PMCID: PMC9702572 DOI: 10.3389/fpls.2022.1012578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 10/03/2022] [Indexed: 06/17/2023]
Abstract
The Aluminum Activated Malate Transporter (ALMT) family members are anion channels that play important roles in organic acid transport, stress resistance, growth, development, fertilization and GABA responses. The rice malate permeable OsALMT7 influences panicle development and grain yield. A truncated OsALMT7 mutant, panicle apical abortion1 (paab1) lacking at least 2 transmembrane helices, mediates reduced malate efflux resulting in yield reducing. Here, we further investigated the contribution of OsALMT7 transmembrane helices to channel activity, using heterologous expression in Xenopus laevis oocytes. We further found that OsALMT7 formed as a homomer by co-expressing OsALMT7 and paab1 proteins in oocytes and detecting the physical interaction between two OsALMT7, and between OsALMT7 and paab1 mutant protein. Further study proved that not just OsALMT7, mutants of TaALMT1 inhibit wild-type TaALMT1 channel, indicating that ALMTs might perform channel function as homomers. Our discovery brings a light for ion channel structure and homomultimer regulation understanding for ALMT anion channels and potential for crop grain yield and stress response improvement in the context of the essential role of ALMTs in these plant processes.
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Affiliation(s)
| | | | | | | | - Yu Long
- *Correspondence: Yu Long, ; Cuizhu Feng,
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7
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Liu J, Shu D, Tan Z, Ma M, Guo N, Gao S, Duan G, Kuai B, Hu Y, Li S, Cui D. The Arabidopsis IDD14 transcription factor interacts with bZIP-type ABFs/AREBs and cooperatively regulates ABA-mediated drought tolerance. THE NEW PHYTOLOGIST 2022; 236:929-942. [PMID: 35842794 DOI: 10.1111/nph.18381] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 07/11/2022] [Indexed: 06/15/2023]
Abstract
The INDETERMINATE DOMAIN (IDD) transcription factors mediate various aspects of plant growth and development. We previously reported that an Arabidopsis IDD subfamily regulates spatial auxin accumulation, and thus organ morphogenesis and gravitropic responses. However, its functions in stress responses are not well defined. Here, we use a combination of physiological, biochemical, molecular, and genetic approaches to provide evidence that the IDD14 cooperates with basic leucine zipper-type binding factors/ABA-responsive element (ABRE)-binding proteins (ABRE-binding factors (ABFs)/AREBs) in ABA-mediated drought tolerance. idd14-1D, a gain-of-function mutant of IDD14, exhibits decreased leaf water loss and improved drought tolerance, whereas inactivation of IDD14 in idd14-1 results in increased transpiration and reduced drought tolerance. Altered IDD14 expression affects ABA sensitivity and ABA-mediated stomatal closure. IDD14 can physically interact with ABF1-4 and subsequently promote their transcriptional activities. Moreover, ectopic expression and mutation of ABFs could, respectively, suppress and enhance plant sensitivity to drought stress in the idd14-1 mutant. Our results demonstrate that IDD14 forms a functional complex with ABFs and positively regulates drought-stress responses, thus revealing a previously unidentified role of IDD14 in ABA signaling and drought responses.
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Affiliation(s)
- Jing Liu
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Defeng Shu
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Zilong Tan
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Mei Ma
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Ning Guo
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
- School of Life Sciences, Shandong Normal University, Jinan, 250014, China
| | - Shan Gao
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Guangyou Duan
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Benke Kuai
- State Key Laboratory of Genetic Engineering and Fudan Center for Genetic Diversity and Designing Agriculture, School of Life Sciences, Fudan University, Shanghai, 200438, China
| | - Yuxin Hu
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Shipeng Li
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
| | - Dayong Cui
- School of Life Sciences, Qilu Normal University, Jinan, 250200, China
- School of Life Sciences, Shandong Normal University, Jinan, 250014, China
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8
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Horaruang W, Klejchová M, Carroll W, Silva-Alvim FAL, Waghmare S, Papanatsiou M, Amtmann A, Hills A, Alvim JC, Blatt MR, Zhang B. Engineering a K + channel 'sensory antenna' enhances stomatal kinetics, water use efficiency and photosynthesis. NATURE PLANTS 2022; 8:1262-1274. [PMID: 36266492 DOI: 10.1038/s41477-022-01255-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 09/12/2022] [Indexed: 06/16/2023]
Abstract
Stomata of plant leaves open to enable CO2 entry for photosynthesis and close to reduce water loss via transpiration. Compared with photosynthesis, stomata respond slowly to fluctuating light, reducing assimilation and water use efficiency. Efficiency gains are possible without a cost to photosynthesis if stomatal kinetics can be accelerated. Here we show that clustering of the GORK channel, which mediates K+ efflux for stomatal closure in the model plant Arabidopsis, arises from binding between the channel voltage sensors, creating an extended 'sensory antenna' for channel gating. Mutants altered in clustering affect channel gating to facilitate K+ flux, accelerate stomatal movements and reduce water use without a loss in biomass. Our findings identify the mechanism coupling channel clustering with gating, and they demonstrate the potential for engineering of ion channels native to the guard cell to enhance stomatal kinetics and improve water use efficiency without a cost in carbon fixation.
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Affiliation(s)
- Wijitra Horaruang
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
- Faculty of Science and Arts, Burapha University, Chanthaburi Campus, Chanthaburi, Thailand
| | - Martina Klejchová
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - William Carroll
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | | | - Sakharam Waghmare
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Maria Papanatsiou
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Anna Amtmann
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Adrian Hills
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Jonas Chaves Alvim
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK.
| | - Ben Zhang
- School of Life Sciences, Shanxi University, Taiyuan City, China
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9
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Higgins JA, Ramos DS, Gili S, Spetea C, Kanoski S, Ha D, McDonough AA, Youn JH. Stable potassium isotopes (41K/39K) track transcellular and paracellular potassium transport in biological systems. Front Physiol 2022; 13:1016242. [PMID: 36388124 PMCID: PMC9644202 DOI: 10.3389/fphys.2022.1016242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 09/21/2022] [Indexed: 12/04/2022] Open
Abstract
As the most abundant cation in archaeal, bacterial, and eukaryotic cells, potassium (K+) is an essential element for life. While much is known about the machinery of transcellular and paracellular K transport–channels, pumps, co-transporters, and tight-junction proteins—many quantitative aspects of K homeostasis in biological systems remain poorly constrained. Here we present measurements of the stable isotope ratios of potassium (41K/39K) in three biological systems (algae, fish, and mammals). When considered in the context of our current understanding of plausible mechanisms of K isotope fractionation and K+ transport in these biological systems, our results provide evidence that the fractionation of K isotopes depends on transport pathway and transmembrane transport machinery. Specifically, we find that passive transport of K+ down its electrochemical potential through channels and pores in tight-junctions at favors 39K, a result which we attribute to a kinetic isotope effect associated with dehydration and/or size selectivity at the channel/pore entrance. In contrast, we find that transport of K+ against its electrochemical gradient via pumps and co-transporters is associated with less/no isotopic fractionation, a result that we attribute to small equilibrium isotope effects that are expressed in pumps/co-transporters due to their slower turnover rate and the relatively long residence time of K+ in the ion pocket. These results indicate that stable K isotopes may be able to provide quantitative constraints on transporter-specific K+ fluxes (e.g., the fraction of K efflux from a tissue by channels vs. co-transporters) and how these fluxes change in different physiological states. In addition, precise determination of K isotope effects associated with K+ transport via channels, pumps, and co-transporters may provide unique constraints on the mechanisms of K transport that could be tested with steered molecular dynamic simulations.
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Affiliation(s)
- John A. Higgins
- Department of Geosciences, Princeton University, Princeton, NJ, United States
- *Correspondence: John A. Higgins,
| | - Danielle Santiago Ramos
- Department of Marine and Coastal Science, Rutgers University, New Brunswick, NJ, United States
| | - Stefania Gili
- Department of Geosciences, Princeton University, Princeton, NJ, United States
| | - Cornelia Spetea
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Scott Kanoski
- Department of Human and Evolutionary Biology, University of Southern California, Los Angeles, CA, United States
| | - Darren Ha
- Department of Physiology and Neuroscience, University of Southern California Keck School of Medicine, Los Angeles, CA, United States
| | - Alicia A. McDonough
- Department of Physiology and Neuroscience, University of Southern California Keck School of Medicine, Los Angeles, CA, United States
| | - Jang H. Youn
- Department of Physiology and Neuroscience, University of Southern California Keck School of Medicine, Los Angeles, CA, United States
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10
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Emiliani V, Entcheva E, Hedrich R, Hegemann P, Konrad KR, Lüscher C, Mahn M, Pan ZH, Sims RR, Vierock J, Yizhar O. Optogenetics for light control of biological systems. NATURE REVIEWS. METHODS PRIMERS 2022; 2:55. [PMID: 37933248 PMCID: PMC10627578 DOI: 10.1038/s43586-022-00136-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/30/2022] [Indexed: 11/08/2023]
Abstract
Optogenetic techniques have been developed to allow control over the activity of selected cells within a highly heterogeneous tissue, using a combination of genetic engineering and light. Optogenetics employs natural and engineered photoreceptors, mostly of microbial origin, to be genetically introduced into the cells of interest. As a result, cells that are naturally light-insensitive can be made photosensitive and addressable by illumination and precisely controllable in time and space. The selectivity of expression and subcellular targeting in the host is enabled by applying control elements such as promoters, enhancers and specific targeting sequences to the employed photoreceptor-encoding DNA. This powerful approach allows precise characterization and manipulation of cellular functions and has motivated the development of advanced optical methods for patterned photostimulation. Optogenetics has revolutionized neuroscience during the past 15 years and is primed to have a similar impact in other fields, including cardiology, cell biology and plant sciences. In this Primer, we describe the principles of optogenetics, review the most commonly used optogenetic tools, illumination approaches and scientific applications and discuss the possibilities and limitations associated with optogenetic manipulations across a wide variety of optical techniques, cells, circuits and organisms.
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Affiliation(s)
- Valentina Emiliani
- Wavefront Engineering Microscopy Group, Photonics Department, Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Emilia Entcheva
- Department of Biomedical Engineering, George Washington University, Washington, DC, USA
| | - Rainer Hedrich
- Julius-von-Sachs Institute for Biosciences, Molecular Plant Physiology and Biophysics, University of Wuerzburg, Wuerzburg, Germany
| | - Peter Hegemann
- Institute for Biology, Experimental Biophysics, Humboldt-Universitaet zu Berlin, Berlin, Germany
| | - Kai R. Konrad
- Julius-von-Sachs Institute for Biosciences, Molecular Plant Physiology and Biophysics, University of Wuerzburg, Wuerzburg, Germany
| | - Christian Lüscher
- Department of Basic Neurosciences, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Clinic of Neurology, Department of Clinical Neurosciences, Geneva University Hospital, Geneva, Switzerland
| | - Mathias Mahn
- Department of Neurobiology, Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Zhuo-Hua Pan
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ruth R. Sims
- Wavefront Engineering Microscopy Group, Photonics Department, Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Johannes Vierock
- Institute for Biology, Experimental Biophysics, Humboldt-Universitaet zu Berlin, Berlin, Germany
- Neuroscience Research Center, Charité – Universitaetsmedizin Berlin, Berlin, Germany
| | - Ofer Yizhar
- Departments of Brain Sciences and Molecular Neuroscience, Weizmann Institute of Science, Rehovot, Israel
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11
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Nieves-Cordones M, Azeem F, Long Y, Boeglin M, Duby G, Mouline K, Hosy E, Vavasseur A, Chérel I, Simonneau T, Gaymard F, Leung J, Gaillard I, Thibaud JB, Véry AA, Boudaoud A, Sentenac H. Non-autonomous stomatal control by pavement cell turgor via the K+ channel subunit AtKC1. THE PLANT CELL 2022; 34:2019-2037. [PMID: 35157082 PMCID: PMC9048897 DOI: 10.1093/plcell/koac038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 01/28/2022] [Indexed: 05/27/2023]
Abstract
Stomata optimize land plants' photosynthetic requirements and limit water vapor loss. So far, all of the molecular and electrical components identified as regulating stomatal aperture are produced, and operate, directly within the guard cells. However, a completely autonomous function of guard cells is inconsistent with anatomical and biophysical observations hinting at mechanical contributions of epidermal origins. Here, potassium (K+) assays, membrane potential measurements, microindentation, and plasmolysis experiments provide evidence that disruption of the Arabidopsis thaliana K+ channel subunit gene AtKC1 reduces pavement cell turgor, due to decreased K+ accumulation, without affecting guard cell turgor. This results in an impaired back pressure of pavement cells onto guard cells, leading to larger stomatal apertures. Poorly rectifying membrane conductances to K+ were consistently observed in pavement cells. This plasmalemma property is likely to play an essential role in K+ shuttling within the epidermis. Functional complementation reveals that restoration of the wild-type stomatal functioning requires the expression of the transgenic AtKC1 at least in the pavement cells and trichomes. Altogether, the data suggest that AtKC1 activity contributes to the building of the back pressure that pavement cells exert onto guard cells by tuning K+ distribution throughout the leaf epidermis.
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Affiliation(s)
| | | | | | - Martin Boeglin
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
| | - Geoffrey Duby
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
| | - Karine Mouline
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
| | | | - Alain Vavasseur
- CEA Cadarache DSV DEVM LEMS UMR 163, CNRS/CEA, F-13108 St Paul Lez Durance, France
| | - Isabelle Chérel
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
| | - Thierry Simonneau
- INRA Laboratoire d’Ecophysiologie des Plantes sous Stress Environnementaux, Place Viala, 2, F-34060 Montpellier Cedex 1, France
| | - Frédéric Gaymard
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
| | - Jeffrey Leung
- Université Paris-Saclay, INRAE, AgroParisTech, CNRS, Institut Jean-Pierre Bourgin (IJPB), 78000 Versailles, France
| | - Isabelle Gaillard
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
| | - Jean-Baptiste Thibaud
- Biochimie et Physiologie Moléculaire des Plantes, UMR BPMP, Univ Montpellier, CNRS, INRAE, Montpellier SupAgro, Montpellier 34060, France
- Institut des biomolécules Max Mousseron (UMR 5247 CNRS-UM-ENSCM) Campus CNRS, 1919 route de Mende, F-34293 Montpellier Cedex 05, France
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12
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Genome-Wide Identification and Characterization of the Shaker-Type K+ Channel Genes in Prunus persica (L.) Batsch. Int J Genomics 2022; 2022:5053838. [PMID: 35310822 PMCID: PMC8926527 DOI: 10.1155/2022/5053838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 02/01/2022] [Accepted: 02/04/2022] [Indexed: 11/17/2022] Open
Abstract
Shaker-type K+ channels are critical for plant K+ acquisition and translocation that play key roles during plant growth and development. However, molecular mechanisms towards K+ channels are extremely rare in fruit trees, especially in peach. In this study, we identified 7 putative shaker-type K+ channel genes from peach, which were unevenly distributed on 5 chromosomes. The peach shaker K+ channel proteins were classified into 5 subfamilies, I-V, and were tightly clustered with pear homologs in the phylogenetic tree. Various cis-acting regulatory elements were detected in the promoter region of the shaker-type K+ channel genes, including phytohormone-responsive, abiotic stress-responsive, and development regulatory elements. The peach shaker K+ channel genes were expressed differentially in distinct tissues, and PpSPIK was specifically expressed in the full-bloom flowers; PpKAT1 and PpGORK were predominantly expressed in the leaves, while PpAKT1, PpKC1, and PpSKOR were majorly expressed in the roots. The peach shaker K+ channel genes were differentially regulated by abiotic stresses in that K+ deficiency, and ABA treatment mainly increased the shaker K+ channel gene expression throughout the whole seedling, whereas NaCl and PEG treatment reduced the shaker K+ channel gene expression, especially in the roots. Moreover, electrophysiological analysis demonstrated that PpSKOR is a typical voltage-dependent outwardly rectifying K+ channel in peach. This study lays a molecular basis for further functional studies of the shaker-type K+ channel genes in peach and provides a theoretical foundation for K+ nutrition and balance research in fruit trees.
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13
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Oh S, Kong Q, Montgomery BL. Guard-cell phytochromes impact seedling photomorphogenesis and rosette leaf morphology. MICROPUBLICATION BIOLOGY 2022; 2022. [PMID: 35128344 PMCID: PMC8808294 DOI: 10.17912/micropub.biology.000521] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/17/2022] [Accepted: 01/24/2022] [Indexed: 11/06/2022]
Abstract
Using a previously established transgenic approach to inactivate phytochrome chromophore synthesis in specific organs or tissues, we used a guard cell-specific promoter to induce phytochrome deficiencies in guard cells of Arabidopsis thaliana. Analyses of multiple homozygous lines depleted of phytochromes in stomatal guard cells indicated elongated hypocotyls specifically in red and far-red growth conditions. Furthermore, rosette leaves of adult plants with guard cell-specific phytochrome deficiencies showed enhanced serration compared to the wild-type Col-0 parent. Thus, we demonstrate that guard cell-localized phytochromes impact the inhibition of hypocotyl elongation, as well as leaf margin morphology of adult rosette leaves in A. thaliana.
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Affiliation(s)
- Sookyung Oh
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Que Kong
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Beronda L Montgomery
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA.,Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA
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14
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Blatt MR, Jezek M, Lew VL, Hills A. What can mechanistic models tell us about guard cells, photosynthesis, and water use efficiency? TRENDS IN PLANT SCIENCE 2022; 27:166-179. [PMID: 34565672 DOI: 10.1016/j.tplants.2021.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 08/19/2021] [Accepted: 08/26/2021] [Indexed: 06/13/2023]
Abstract
Stomatal pores facilitate gaseous exchange between the inner air spaces of the leaf and the atmosphere. The pores open to enable CO2 entry for photosynthesis and close to reduce transpirational water loss. How stomata respond to the environment has long attracted interest in modeling as a tool to understand the consequences for the plant and for the ecosystem. Models that focus on stomatal conductance for gas exchange make intuitive sense, but such models need also to connect with the mechanics of the guard cells that regulate pore aperture if we are to understand the 'decisions made' by stomata, their impacts on the plant and on the global environment.
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Affiliation(s)
- Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow G12 8QQ, UK.
| | - Mareike Jezek
- Journal of Experimental Botany, Lancaster University, Lancaster LA1 4YW, UK
| | - Virgilio L Lew
- The Physiological Laboratory, University of Cambridge, Cambridge CB2 3EG, UK
| | - Adrian Hills
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow G12 8QQ, UK
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15
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Kashtoh H, Baek KH. Structural and Functional Insights into the Role of Guard Cell Ion Channels in Abiotic Stress-Induced Stomatal Closure. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10122774. [PMID: 34961246 PMCID: PMC8707303 DOI: 10.3390/plants10122774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Revised: 11/25/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
A stomatal pore is formed by a pair of specialized guard cells and serves as a major gateway for water transpiration and atmospheric CO2 influx for photosynthesis in plants. These pores must be tightly controlled, as inadequate CO2 intake and excessive water loss are devastating for plants. When the plants are exposed to extreme weather conditions such as high CO2 levels, O3, low air humidity, and drought, the turgor pressure of the guard cells exhibits an appropriate response against these stresses, which leads to stomatal closure. This phenomenon involves a complex network of ion channels and their regulation. It is well-established that the turgor pressure of guard cells is regulated by ions transportation across the membrane, such as anions and potassium ions. In this review, the guard cell ion channels are discussed, highlighting the structure and functions of key ion channels; the SLAC1 anion channel and KAT1 potassium channel, and their regulatory components, emphasizing their significance in guard cell response to various stimuli.
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16
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Lefoulon C. The bare necessities of plant K+ channel regulation. PLANT PHYSIOLOGY 2021; 187:2092-2109. [PMID: 34618033 PMCID: PMC8644596 DOI: 10.1093/plphys/kiab266] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 05/11/2021] [Indexed: 05/29/2023]
Abstract
Potassium (K+) channels serve a wide range of functions in plants from mineral nutrition and osmotic balance to turgor generation for cell expansion and guard cell aperture control. Plant K+ channels are members of the superfamily of voltage-dependent K+ channels, or Kv channels, that include the Shaker channels first identified in fruit flies (Drosophila melanogaster). Kv channels have been studied in depth over the past half century and are the best-known of the voltage-dependent channels in plants. Like the Kv channels of animals, the plant Kv channels are regulated over timescales of milliseconds by conformational mechanisms that are commonly referred to as gating. Many aspects of gating are now well established, but these channels still hold some secrets, especially when it comes to the control of gating. How this control is achieved is especially important, as it holds substantial prospects for solutions to plant breeding with improved growth and water use efficiencies. Resolution of the structure for the KAT1 K+ channel, the first channel from plants to be crystallized, shows that many previous assumptions about how the channels function need now to be revisited. Here, I strip the plant Kv channels bare to understand how they work, how they are gated by voltage and, in some cases, by K+ itself, and how the gating of these channels can be regulated by the binding with other protein partners. Each of these features of plant Kv channels has important implications for plant physiology.
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Affiliation(s)
- Cécile Lefoulon
- Laboratory of Plant Physiology and Biophysics, Bower Building, University of Glasgow, Glasgow G12 8QQ, Scotland
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17
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Lhamo D, Wang C, Gao Q, Luan S. Recent Advances in Genome-wide Analyses of Plant Potassium Transporter Families. Curr Genomics 2021; 22:164-180. [PMID: 34975289 PMCID: PMC8640845 DOI: 10.2174/1389202922666210225083634] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 12/30/2020] [Accepted: 01/26/2021] [Indexed: 12/19/2022] Open
Abstract
Plants require potassium (K+) as a macronutrient to support numerous physiological processes. Understanding how this nutrient is transported, stored, and utilized within plants is crucial for breeding crops with high K+ use efficiency. As K+ is not metabolized, cross-membrane transport becomes a rate-limiting step for efficient distribution and utilization in plants. Several K+ transporter families, such as KUP/HAK/KT and KEA transporters and Shaker-like and TPK channels, play dominant roles in plant K+ transport processes. In this review, we provide a comprehensive contemporary overview of our knowledge about these K+ transporter families in angiosperms, with a major focus on the genome-wide identification of K+ transporter families, subcellular localization, spatial expression, function and regulation. We also expanded the genome-wide search for the K+ transporter genes and examined their tissue-specific expression in Camelina sativa, a polyploid oil-seed crop with a potential to adapt to marginal lands for biofuel purposes and contribution to sustainable agriculture. In addition, we present new insights and emphasis on the study of K+ transporters in polyploids in an effort to generate crops with high K+ Utilization Efficiency (KUE).
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Affiliation(s)
- Dhondup Lhamo
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Chao Wang
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Qifei Gao
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
| | - Sheng Luan
- 1Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; 2School of Life Sciences, Northwest University, Xi'an 710069, China
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18
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Monder H, Maillard M, Chérel I, Zimmermann SD, Paris N, Cuéllar T, Gaillard I. Adjustment of K + Fluxes and Grapevine Defense in the Face of Climate Change. Int J Mol Sci 2021; 22:10398. [PMID: 34638737 PMCID: PMC8508874 DOI: 10.3390/ijms221910398] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 12/18/2022] Open
Abstract
Grapevine is one of the most economically important fruit crops due to the high value of its fruit and its importance in winemaking. The current decrease in grape berry quality and production can be seen as the consequence of various abiotic constraints imposed by climate changes. Specifically, produced wines have become too sweet, with a stronger impression of alcohol and fewer aromatic qualities. Potassium is known to play a major role in grapevine growth, as well as grape composition and wine quality. Importantly, potassium ions (K+) are involved in the initiation and maintenance of the berry loading process during ripening. Moreover, K+ has also been implicated in various defense mechanisms against abiotic stress. The first part of this review discusses the main negative consequences of the current climate, how they disturb the quality of grape berries at harvest and thus ultimately compromise the potential to obtain a great wine. In the second part, the essential electrical and osmotic functions of K+, which are intimately dependent on K+ transport systems, membrane energization, and cell K+ homeostasis, are presented. This knowledge will help to select crops that are better adapted to adverse environmental conditions.
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Affiliation(s)
- Houssein Monder
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, F-34060 Montpellier, France; (H.M.); (M.M.); (I.C.); (S.D.Z.); (N.P.)
| | - Morgan Maillard
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, F-34060 Montpellier, France; (H.M.); (M.M.); (I.C.); (S.D.Z.); (N.P.)
| | - Isabelle Chérel
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, F-34060 Montpellier, France; (H.M.); (M.M.); (I.C.); (S.D.Z.); (N.P.)
| | - Sabine Dagmar Zimmermann
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, F-34060 Montpellier, France; (H.M.); (M.M.); (I.C.); (S.D.Z.); (N.P.)
| | - Nadine Paris
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, F-34060 Montpellier, France; (H.M.); (M.M.); (I.C.); (S.D.Z.); (N.P.)
| | - Teresa Cuéllar
- CIRAD, UMR AGAP, Univ Montpellier, INRAE, Institut Agro, F-34398 Montpellier, France;
| | - Isabelle Gaillard
- BPMP, Univ Montpellier, CNRS, INRAE, Institut Agro, F-34060 Montpellier, France; (H.M.); (M.M.); (I.C.); (S.D.Z.); (N.P.)
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19
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Boher P, Soler M, Fernández-Piñán S, Torrent X, Müller SY, Kelly KA, Serra O, Figueras M. Silencing of StRIK in potato suggests a role in periderm related to RNA processing and stress. BMC PLANT BIOLOGY 2021; 21:409. [PMID: 34493224 PMCID: PMC8424952 DOI: 10.1186/s12870-021-03141-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 07/06/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND The periderm is a protective barrier crucial for land plant survival, but little is known about genetic factors involved in its development and regulation. Using a transcriptomic approach in the cork oak (Q. suber) periderm, we previously identified an RS2-INTERACTING KH PROTEIN (RIK) homologue of unknown function containing a K homology (KH)-domain RNA-binding protein, as a regulatory candidate gene in the periderm. RESULTS To gain insight into the function of RIK in the periderm, potato (S. tuberosum) tuber periderm was used as a model: the full-length coding sequence of RIK, hereafter referred to as StRIK, was isolated, the transcript profile analyzed and gene silencing in potato performed to analyze the silencing effects on periderm anatomy and transcriptome. The StRIK transcript accumulated in all vegetative tissues studied, including periderm and other suberized tissues such as root and also in wounded tissues. Downregulation of StRIK in potato by RNA interference (StRIK-RNAi) did not show any obvious effects on tuber periderm anatomy but, unlike Wild type, transgenic plants flowered. Global transcript profiling of the StRIK-RNAi periderm did show altered expression of genes associated with RNA metabolism, stress and signaling, mirroring the biological processes found enriched within the in silico co-expression network of the Arabidopsis orthologue. CONCLUSIONS The ubiquitous expression of StRIK transcript, the flower associated phenotype and the differential expression of StRIK-RNAi periderm point out to a general regulatory role of StRIK in diverse plant developmental processes. The transcriptome analysis suggests that StRIK might play roles in RNA maturation and stress response in the periderm.
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Affiliation(s)
- Pau Boher
- Laboratori del Suro, Biology Department, Universitat de Girona, Campus Montilivi, E-17071 Girona, Catalonia Spain
| | - Marçal Soler
- Laboratori del Suro, Biology Department, Universitat de Girona, Campus Montilivi, E-17071 Girona, Catalonia Spain
| | - Sandra Fernández-Piñán
- Laboratori del Suro, Biology Department, Universitat de Girona, Campus Montilivi, E-17071 Girona, Catalonia Spain
| | - Xènia Torrent
- Laboratori del Suro, Biology Department, Universitat de Girona, Campus Montilivi, E-17071 Girona, Catalonia Spain
| | - Sebastian Y. Müller
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA UK
| | - Krystyna A. Kelly
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EA UK
| | - Olga Serra
- Laboratori del Suro, Biology Department, Universitat de Girona, Campus Montilivi, E-17071 Girona, Catalonia Spain
| | - Mercè Figueras
- Laboratori del Suro, Biology Department, Universitat de Girona, Campus Montilivi, E-17071 Girona, Catalonia Spain
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20
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Jezek M, Silva-Alvim FAL, Hills A, Donald N, Ishka MR, Shadbolt J, He B, Lawson T, Harper JF, Wang Y, Lew VL, Blatt MR. Guard cell endomembrane Ca 2+-ATPases underpin a 'carbon memory' of photosynthetic assimilation that impacts on water-use efficiency. NATURE PLANTS 2021; 7:1301-1313. [PMID: 34326530 DOI: 10.1038/s41477-021-00966-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 06/14/2021] [Indexed: 06/13/2023]
Abstract
Stomata of most plants close to preserve water when the demand for CO2 by photosynthesis is reduced. Stomatal responses are slow compared with photosynthesis, and this kinetic difference erodes assimilation and water-use efficiency under fluctuating light. Despite a deep knowledge of guard cells that regulate the stoma, efforts to enhance stomatal kinetics are limited by our understanding of its control by foliar CO2. Guided by mechanistic modelling that incorporates foliar CO2 diffusion and mesophyll photosynthesis, here we uncover a central role for endomembrane Ca2+ stores in guard cell responsiveness to fluctuating light and CO2. Modelling predicted and experiments demonstrated a delay in Ca2+ cycling that was enhanced by endomembrane Ca2+-ATPase mutants, altering stomatal conductance and reducing assimilation and water-use efficiency. Our findings illustrate the power of modelling to bridge the gap from the guard cell to whole-plant photosynthesis, and they demonstrate an unforeseen latency, or 'carbon memory', of guard cells that affects stomatal dynamics, photosynthesis and water-use efficiency.
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Affiliation(s)
- Mareike Jezek
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | | | - Adrian Hills
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Naomi Donald
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Maryam Rahmati Ishka
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
| | - Jessica Shadbolt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK
| | - Bingqing He
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Tracy Lawson
- School of Life Sciences, University of Essex, Colchester, UK
| | - Jeffrey F Harper
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, USA
| | - Yizhou Wang
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Virgilio L Lew
- Physiological Laboratory, University of Cambridge, Cambridge, UK
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow, UK.
- Institute of Crop Science, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
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21
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Britto DT, Coskun D, Kronzucker HJ. Potassium physiology from Archean to Holocene: A higher-plant perspective. JOURNAL OF PLANT PHYSIOLOGY 2021; 262:153432. [PMID: 34034042 DOI: 10.1016/j.jplph.2021.153432] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/22/2021] [Accepted: 04/22/2021] [Indexed: 05/27/2023]
Abstract
In this paper, we discuss biological potassium acquisition and utilization processes over an evolutionary timescale, with emphasis on modern vascular plants. The quintessential osmotic and electrical functions of the K+ ion are shown to be intimately tied to K+-transport systems and membrane energization. Several prominent themes in plant K+-transport physiology are explored in greater detail, including: (1) channel mediated K+ acquisition by roots at low external [K+]; (2) K+ loading of root xylem elements by active transport; (3) variations on the theme of K+ efflux from root cells to the extracellular environment; (4) the veracity and utility of the "affinity" concept in relation to transport systems. We close with a discussion of the importance of plant-potassium relations to our human world, and current trends in potassium nutrition from farm to table.
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Affiliation(s)
- Dev T Britto
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Devrim Coskun
- Département de Phytologie, Faculté des Sciences de l'Agriculture et de l'Alimentation (FSAA), Université Laval, Québec, QC, G1V 0A6, Canada
| | - Herbert J Kronzucker
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; School of BioSciences, The University of Melbourne, Parkville, Victoria, 3010, Australia.
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22
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Lhamo D, Luan S. Potential Networks of Nitrogen-Phosphorus-Potassium Channels and Transporters in Arabidopsis Roots at a Single Cell Resolution. FRONTIERS IN PLANT SCIENCE 2021; 12:689545. [PMID: 34220911 PMCID: PMC8242960 DOI: 10.3389/fpls.2021.689545] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/24/2021] [Indexed: 05/08/2023]
Abstract
Nitrogen (N), phosphorus (P), and potassium (K) are three major macronutrients essential for plant life. These nutrients are acquired and transported by several large families of transporters expressed in plant roots. However, it remains largely unknown how these transporters are distributed in different cell-types that work together to transfer the nutrients from the soil to different layers of root cells and eventually reach vasculature for massive flow. Using the single cell transcriptomics data from Arabidopsis roots, we profiled the transcriptional patterns of putative nutrient transporters in different root cell-types. Such analyses identified a number of uncharacterized NPK transporters expressed in the root epidermis to mediate NPK uptake and distribution to the adjacent cells. Some transport genes showed cortex- and endodermis-specific expression to direct the nutrient flow toward the vasculature. For long-distance transport, a variety of transporters were shown to express and potentially function in the xylem and phloem. In the context of subcellular distribution of mineral nutrients, the NPK transporters at subcellular compartments were often found to show ubiquitous expression patterns, which suggests function in house-keeping processes. Overall, these single cell transcriptomic analyses provide working models of nutrient transport from the epidermis across the cortex to the vasculature, which can be further tested experimentally in the future.
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Affiliation(s)
- Dhondup Lhamo
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, United States
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23
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Li JH, Fan LF, Zhao DJ, Zhou Q, Yao JP, Wang ZY, Huang L. Plant electrical signals: A multidisciplinary challenge. JOURNAL OF PLANT PHYSIOLOGY 2021; 261:153418. [PMID: 33887526 DOI: 10.1016/j.jplph.2021.153418] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/06/2021] [Accepted: 04/06/2021] [Indexed: 05/15/2023]
Abstract
Plant electrical signals, an early event in the plant-stimulus interaction, rapidly transmit information generated by the stimulus to other organs, and even the whole plant, to promote the corresponding response and trigger a regulatory cascade. In recent years, many promising state-of-the-art technologies applicable to study plant electrophysiology have emerged. Research focused on expression of genes associated with electrical signals has also proliferated. We propose that it is appropriate for plant electrical signals to be considered in the form of a "plant electrophysiological phenotype". This review synthesizes research on plant electrical signals from a novel, interdisciplinary perspective, which is needed to improve the efficient aggregation and use of plant electrical signal data and to expedite interpretation of plant electrical signals.
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Affiliation(s)
- Jin-Hai Li
- College of Information and Electrical Engineering, China Agricultural University, Beijing, 100083, China; Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, Beijing, 100083, China
| | - Li-Feng Fan
- College of Information and Electrical Engineering, China Agricultural University, Beijing, 100083, China; Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, Beijing, 100083, China
| | - Dong-Jie Zhao
- Institute for Future (IFF), Qingdao University, Qingdao, 266071, China
| | - Qiao Zhou
- College of Information and Electrical Engineering, China Agricultural University, Beijing, 100083, China; Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, Beijing, 100083, China
| | - Jie-Peng Yao
- College of Information and Electrical Engineering, China Agricultural University, Beijing, 100083, China; Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, Beijing, 100083, China
| | - Zhong-Yi Wang
- College of Information and Electrical Engineering, China Agricultural University, Beijing, 100083, China; Key Laboratory of Modern Precision Agriculture System Integration Research, Ministry of Education, Beijing, 100083, China; Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, Beijing, 100083, China.
| | - Lan Huang
- College of Information and Electrical Engineering, China Agricultural University, Beijing, 100083, China; Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture, Beijing, 100083, China.
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24
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Isolation and Functional Determination of SKOR Potassium Channel in Purple Osier Willow, Salix purpurea. Int J Genomics 2021; 2021:6669509. [PMID: 33708988 PMCID: PMC7932800 DOI: 10.1155/2021/6669509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 11/17/2022] Open
Abstract
Potassium (K+) plays key roles in plant growth and development. However, molecular mechanism studies of K+ nutrition in forest plants are largely rare. In plants, SKOR gene encodes for the outward rectifying Shaker-type K+ channel that is responsible for the long-distance transportation of K+ through xylem in roots. In this study, we determined a Shaker-type K+ channel gene in purple osier (Salix purpurea), designated as SpuSKOR, and determined its function using a patch clamp electrophysiological system. SpuSKOR was closely clustered with poplar PtrSKOR in the phylogenetic tree. Quantitative real-time PCR (qRT-PCR) analyses demonstrated that SpuSKOR was predominantly expressed in roots, and expression decreased under K+ depletion conditions. Patch clamp analysis via HEK293-T cells demonstrated that the activity of the SpuSKOR channel was activated when the cell membrane voltage reached at -10 mV, and the channel activity was enhanced along with the increase of membrane voltage. Outward currents were recorded and induced in response to the decrease of external K+ concentration. Our results indicate that SpuSKOR is a typical voltage dependent outwardly rectifying K+ channel in purple osier. This study provides theoretical basis for revealing the mechanism of K+ transport and distribution in woody plants.
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25
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Wong JH, Klejchová M, Snipes SA, Nagpal P, Bak G, Wang B, Dunlap S, Park MY, Kunkel EN, Trinidad B, Reed JW, Blatt MR, Gray WM. SAUR proteins and PP2C.D phosphatases regulate H+-ATPases and K+ channels to control stomatal movements. PLANT PHYSIOLOGY 2021; 185:256-273. [PMID: 33631805 PMCID: PMC8133658 DOI: 10.1093/plphys/kiaa023] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 10/27/2020] [Indexed: 05/12/2023]
Abstract
Activation of plasma membrane (PM) H+-ATPase activity is crucial in guard cells to promote light-stimulated stomatal opening, and in growing organs to promote cell expansion. In growing organs, SMALL AUXIN UP RNA (SAUR) proteins inhibit the PP2C.D2, PP2C.D5, and PP2C.D6 (PP2C.D2/5/6) phosphatases, thereby preventing dephosphorylation of the penultimate phosphothreonine of PM H+-ATPases and trapping them in the activated state to promote cell expansion. To elucidate whether SAUR-PP2C.D regulatory modules also affect reversible cell expansion, we examined stomatal apertures and conductances of Arabidopsis thaliana plants with altered SAUR or PP2C.D activity. Here, we report that the pp2c.d2/5/6 triple knockout mutant plants and plant lines overexpressing SAUR fusion proteins exhibit enhanced stomatal apertures and conductances. Reciprocally, saur56 saur60 double mutants, lacking two SAUR genes normally expressed in guard cells, displayed reduced apertures and conductances, as did plants overexpressing PP2C.D5. Although altered PM H+-ATPase activity contributes to these stomatal phenotypes, voltage clamp analysis showed significant changes also in K+ channel gating in lines with altered SAUR and PP2C.D function. Together, our findings demonstrate that SAUR and PP2C.D proteins act antagonistically to facilitate stomatal movements through a concerted targeting of both ATP-dependent H+ pumping and channel-mediated K+ transport.
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Affiliation(s)
- Jeh Haur Wong
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, Minnesota 55108, USA
- Present address: Department of Biological Sciences, National University of Singapore, Singapore
| | - Martina Klejchová
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow G12 8QQ, UK
| | - Stephen A Snipes
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Punita Nagpal
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Gwangbae Bak
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Bryan Wang
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Sonja Dunlap
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Mee Yeon Park
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, Minnesota 55108, USA
| | - Emma N Kunkel
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Brendan Trinidad
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Jason W Reed
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599-3280, USA
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow G12 8QQ, UK
| | - William M Gray
- Department of Plant and Microbial Biology, University of Minnesota, St Paul, Minnesota 55108, USA
- Author for communication:
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26
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Sardans J, Peñuelas J. Potassium Control of Plant Functions: Ecological and Agricultural Implications. PLANTS (BASEL, SWITZERLAND) 2021; 10:419. [PMID: 33672415 PMCID: PMC7927068 DOI: 10.3390/plants10020419] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/18/2021] [Accepted: 02/21/2021] [Indexed: 02/06/2023]
Abstract
Potassium, mostly as a cation (K+), together with calcium (Ca2+) are the most abundant inorganic chemicals in plant cellular media, but they are rarely discussed. K+ is not a component of molecular or macromolecular plant structures, thus it is more difficult to link it to concrete metabolic pathways than nitrogen or phosphorus. Over the last two decades, many studies have reported on the role of K+ in several physiological functions, including controlling cellular growth and wood formation, xylem-phloem water content and movement, nutrient and metabolite transport, and stress responses. In this paper, we present an overview of contemporary findings associating K+ with various plant functions, emphasizing plant-mediated responses to environmental abiotic and biotic shifts and stresses by controlling transmembrane potentials and water, nutrient, and metabolite transport. These essential roles of K+ account for its high concentrations in the most active plant organs, such as leaves, and are consistent with the increasing number of ecological and agricultural studies that report K+ as a key element in the function and structure of terrestrial ecosystems, crop production, and global food security. We synthesized these roles from an integrated perspective, considering the metabolic and physiological functions of individual plants and their complex roles in terrestrial ecosystem functions and food security within the current context of ongoing global change. Thus, we provide a bridge between studies of K+ at the plant and ecological levels to ultimately claim that K+ should be considered at least at a level similar to N and P in terrestrial ecological studies.
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Affiliation(s)
- Jordi Sardans
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, 08913 Bellaterra, Catalonia, Spain;
- CREAF, 08913 Cerdanyola del Vallès, Catalonia, Spain
| | - Josep Peñuelas
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, 08913 Bellaterra, Catalonia, Spain;
- CREAF, 08913 Cerdanyola del Vallès, Catalonia, Spain
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27
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Ronzier E, Corratgé-Faillie C, Sanchez F, Brière C, Xiong TC. Ca 2+-Dependent Protein Kinase 6 Enhances KAT2 Shaker Channel Activity in Arabidopsis thaliana. Int J Mol Sci 2021; 22:ijms22041596. [PMID: 33562460 PMCID: PMC7914964 DOI: 10.3390/ijms22041596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/25/2021] [Accepted: 02/01/2021] [Indexed: 11/16/2022] Open
Abstract
Post-translational regulations of Shaker-like voltage-gated K+ channels were reported to be essential for rapid responses to environmental stresses in plants. In particular, it has been shown that calcium-dependent protein kinases (CPKs) regulate Shaker channels in plants. Here, the focus was on KAT2, a Shaker channel cloned in the model plant Arabidopsis thaliana, where is it expressed namely in the vascular tissues of leaves. After co-expression of KAT2 with AtCPK6 in Xenopuslaevis oocytes, voltage-clamp recordings demonstrated that AtCPK6 stimulates the activity of KAT2 in a calcium-dependent manner. A physical interaction between these two proteins has also been shown by Förster resonance energy transfer by fluorescence lifetime imaging (FRET-FLIM). Peptide array assays support that AtCPK6 phosphorylates KAT2 at several positions, also in a calcium-dependent manner. Finally, K+ fluorescence imaging in planta suggests that K+ distribution is impaired in kat2 knock-out mutant leaves. We propose that the AtCPK6/KAT2 couple plays a role in the homeostasis of K+ distribution in leaves.
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Affiliation(s)
- Elsa Ronzier
- BPMP, University Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France; (E.R.); (C.C.-F.); (F.S.)
| | - Claire Corratgé-Faillie
- BPMP, University Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France; (E.R.); (C.C.-F.); (F.S.)
| | - Frédéric Sanchez
- BPMP, University Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France; (E.R.); (C.C.-F.); (F.S.)
- BIOM 7232, Avenue Pierre Fabre, 66650 Banyuls-Sur-Mer, France
| | - Christian Brière
- Laboratoire de Recherche en Sciences Végétales, UMR CNRS/UPS 5546, 24 chemin de Borde Rouge, 31326 Castanet-Tolosan, France;
| | - Tou Cheu Xiong
- BPMP, University Montpellier, CNRS, INRAE, Institut Agro, 34060 Montpellier, France; (E.R.); (C.C.-F.); (F.S.)
- Correspondence:
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28
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Dreyer I, Sussmilch FC, Fukushima K, Riadi G, Becker D, Schultz J, Hedrich R. How to Grow a Tree: Plant Voltage-Dependent Cation Channels in the Spotlight of Evolution. TRENDS IN PLANT SCIENCE 2021; 26:41-52. [PMID: 32868178 DOI: 10.1016/j.tplants.2020.07.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
Phylogenetic analysis can be a powerful tool for generating hypotheses regarding the evolution of physiological processes. Here, we provide an updated view of the evolution of the main cation channels in plant electrical signalling: the Shaker family of voltage-gated potassium channels and the two-pore cation (K+) channel (TPC1) family. Strikingly, the TPC1 family followed the same conservative evolutionary path as one particular subfamily of Shaker channels (Kout) and remained highly invariant after terrestrialisation, suggesting that electrical signalling was, and remains, key to survival on land. We note that phylogenetic analyses can have pitfalls, which may lead to erroneous conclusions. To avoid these in the future, we suggest guidelines for analyses of ion channel evolution in plants.
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Affiliation(s)
- Ingo Dreyer
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile.
| | - Frances C Sussmilch
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany; School of Natural Sciences, University of Tasmania, Hobart, TAS 7001, Australia
| | - Kenji Fukushima
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
| | - Gonzalo Riadi
- Center for Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, 2 Norte 685, Talca, Chile
| | - Dirk Becker
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
| | - Jörg Schultz
- Department of Bioinformatics, Biozentrum, University of Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany.
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29
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Iosip AL, Böhm J, Scherzer S, Al-Rasheid KAS, Dreyer I, Schultz J, Becker D, Kreuzer I, Hedrich R. The Venus flytrap trigger hair-specific potassium channel KDM1 can reestablish the K+ gradient required for hapto-electric signaling. PLoS Biol 2020; 18:e3000964. [PMID: 33296375 PMCID: PMC7725304 DOI: 10.1371/journal.pbio.3000964] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 11/05/2020] [Indexed: 12/18/2022] Open
Abstract
The carnivorous plant Dionaea muscipula harbors multicellular trigger hairs designed to sense mechanical stimuli upon contact with animal prey. At the base of the trigger hair, mechanosensation is transduced into an all-or-nothing action potential (AP) that spreads all over the trap, ultimately leading to trap closure and prey capture. To reveal the molecular basis for the unique functional repertoire of this mechanoresponsive plant structure, we determined the transcriptome of D. muscipula’s trigger hair. Among the genes that were found to be highly specific to the trigger hair, the Shaker-type channel KDM1 was electrophysiologically characterized as a hyperpolarization- and acid-activated K+-selective channel, thus allowing the reuptake of K+ ions into the trigger hair’s sensory cells during the hyperpolarization phase of the AP. During trap development, the increased electrical excitability of the trigger hair is associated with the transcriptional induction of KDM1. Conversely, when KDM1 is blocked by Cs+ in adult traps, the initiation of APs in response to trigger hair deflection is reduced, and trap closure is suppressed. KDM1 thus plays a dominant role in K+ homeostasis in the context of AP and turgor formation underlying the mechanosensation of trigger hair cells and thus D. muscipula’s hapto-electric signaling. Transcriptomic and electrophysiological studies of the carnivorous Venus flytrap reveal that potassium uptake via a trigger hair-specific potassium channel builds the basis for mechanosensation of likely prey and generation of an action potential that triggers closure of the trap.
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Affiliation(s)
- Anda L. Iosip
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | - Jennifer Böhm
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Sönke Scherzer
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | | | - Ingo Dreyer
- Center of Bioinformatics, Simulation and Modeling (CBSM), Faculty of Engineering, Universidad de Talca, Talca, Chile
| | - Jörg Schultz
- Center for Computational and Theoretical Biology, University of Würzburg, Würzburg, Germany
| | - Dirk Becker
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
| | - Ines Kreuzer
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
- * E-mail: (IK); (RH)
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, University of Würzburg, Würzburg, Germany
- * E-mail: (IK); (RH)
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30
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Jin R, Zhang A, Sun J, Chen X, Liu M, Zhao P, Jiang W, Tang Z. Identification of Shaker K + channel family members in sweetpotato and functional exploration of IbAKT1. Gene 2020; 768:145311. [PMID: 33220344 DOI: 10.1016/j.gene.2020.145311] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 10/10/2020] [Accepted: 11/13/2020] [Indexed: 01/27/2023]
Abstract
The Shaker K+ channel family plays a vital role in potassium absorption and stress resistance in plants. However little information on the genes family is available about sweetpotato. In the present study, eleven sweetpotato Shaker K+ channel genes were identified and classified into five groups based on phylogenetic relationships, conserved motifs, and gene structure analyses. Based on synteny analysis, four duplicated gene pairs were identified, derived from both ancient and recent duplication, whereas only one resulted from tandem duplication events. Different expression pattern of Shaker K+ channel genes in roots of Xu32 and NZ1 resulted in different K+ deficiency tolerances, suggesting there is different mechanism of K+ uptake in sweetpotato cultivars with different K+-tolerance levels. Quantitative real-time PCR analysis revealed that the shaker K+ channel genes responded to drought and high salt stresses. Higher K+ influx under normal condition and lower K+ efflux under K+ deficiency stress were observed in IbAKT1 overexpressing transgenic roots than in adventitious roots, which indicated that IbAKT1 may play an important role in the regulation of K+ deficiency tolerance in sweetpotato. This is the first genome-wide analysis of Shaker K+ channel genes and the first functional analysis of IbAKT1 in sweetpotato. Our results provide valuable information on the gene structure, evolution, expression and functions of the Shaker K+ channel gene family in sweetpotato.
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Affiliation(s)
- Rong Jin
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China
| | - Aijun Zhang
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China
| | - Jian Sun
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, Jiangsu, China
| | - Xiaoguang Chen
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China
| | - Ming Liu
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China
| | - Peng Zhao
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China
| | - Wei Jiang
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China
| | - Zhonghou Tang
- Xuzhou Sweetpotato Research Center, Xuzhou Institute of Agricultural Sciences, Jiangsu, China; Key Laboratory of Sweetpotato Biology and Genetic Breeding, Ministry of Agriculture, Xuzhou, China.
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31
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Li S, Yang F, Sun D, Zhang Y, Zhang M, Liu S, Zhou P, Shi C, Zhang L, Tian C. Cryo-EM structure of the hyperpolarization-activated inwardly rectifying potassium channel KAT1 from Arabidopsis. Cell Res 2020; 30:1049-1052. [PMID: 32901112 PMCID: PMC7784887 DOI: 10.1038/s41422-020-00407-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 08/13/2020] [Indexed: 12/13/2022] Open
Affiliation(s)
- Siyu Li
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Fan Yang
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Demeng Sun
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Yong Zhang
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Mengge Zhang
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Sanling Liu
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Peng Zhou
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230030, China
| | - Chaowei Shi
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Longhua Zhang
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
| | - Changlin Tian
- Hefei National Laboratory of Physical Sciences at Microscale, Anhui Laboratory of Advanced Photonic Science and Technology and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
- High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, Anhui 230030, China.
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32
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Jose J, Roy Choudhury S. Heterotrimeric G-proteins mediated hormonal responses in plants. Cell Signal 2020; 76:109799. [PMID: 33011291 DOI: 10.1016/j.cellsig.2020.109799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 01/27/2023]
Abstract
Phytohormones not only orchestrate intrinsic developmental programs from germination to senescence but also regulate environmental inputs through complex signalling pathways. Despite building an own signalling network, hormones mutually contribute several signalling systems, which are also essential for plant growth and development, defense, and responses to abiotic stresses. One of such important signalling cascades is G-proteins, which act as critical regulators of a wide range of fundamental cellular processes by transducing receptor signals to the intracellular environment. G proteins are composed of α, β, and γ subunits, and the molecular switching between active and inactive conformation of Gα controls the signalling cycle. The active GTP bound Gα and freed Gβγ have both independent and tightly coordinated roles in the regulation of effector molecules, thereby modulating multiple responses, including hormonal responses. Therefore, an interplay of hormones with G-proteins fine-tunes multiple biological processes of plants; however, their molecular mechanisms are largely unknown. Functional characterization of hormone biosynthesis, perception, and signalling components, as well as identification of few effector molecules of G-proteins and their interaction networks, reduces the complexity of the hormonal signalling networks related to G-proteins. In this review, we highlight a valuable insight into the mechanisms of how the G-protein signalling cascades connect with hormonal responses to regulate increased developmental flexibility as well as remarkable plasticity of plants.
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Affiliation(s)
- Jismon Jose
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517507, India
| | - Swarup Roy Choudhury
- Department of Biology, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh 517507, India.
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33
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Kocourková D, Krčková Z, Pejchar P, Kroumanová K, Podmanická T, Daněk M, Martinec J. Phospholipase Dα1 mediates the high-Mg 2+ stress response partially through regulation of K + homeostasis. PLANT, CELL & ENVIRONMENT 2020; 43:2460-2475. [PMID: 32583878 DOI: 10.1111/pce.13831] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 06/13/2020] [Accepted: 06/14/2020] [Indexed: 05/28/2023]
Abstract
Intracellular levels of Mg2+ are tightly regulated, as Mg2+ deficiency or excess affects normal plant growth and development. In Arabidopsis, we determined that phospholipase Dα1 (PLDα1) is involved in the stress response to high-magnesium conditions. The T-DNA insertion mutant pldα1 is hypersensitive to increased concentrations of magnesium, exhibiting reduced primary root length and fresh weight. PLDα1 activity increases rapidly after high-Mg2+ treatment, and this increase was found to be dose dependent. Two lines harbouring mutations in the HKD motif, which is essential for PLDα1 activity, displayed the same high-Mg2+ hypersensitivity of pldα1 plants. Moreover, we show that high concentrations of Mg2+ disrupt K+ homeostasis, and that transcription of K+ homeostasis-related genes CIPK9 and HAK5 is impaired in pldα1. Additionally, we found that the akt1, hak5 double mutant is hypersensitive to high-Mg2+ . We conclude that in Arabidopsis, the enzyme activity of PLDα1 is vital in the response to high-Mg2+ conditions, and that PLDα1 mediates this response partially through regulation of K+ homeostasis.
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Affiliation(s)
- Daniela Kocourková
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Zuzana Krčková
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Přemysl Pejchar
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Kristýna Kroumanová
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Tereza Podmanická
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Michal Daněk
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jan Martinec
- Institute of Experimental Botany of the Czech Academy of Sciences, Prague, Czech Republic
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Deng K, Wang W, Feng L, Yin H, Xiong F, Ren M. Target of rapamycin regulates potassium uptake in Arabidopsis and potato. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2020; 155:357-366. [PMID: 32798904 DOI: 10.1016/j.plaphy.2020.07.044] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/24/2020] [Accepted: 07/24/2020] [Indexed: 06/11/2023]
Abstract
Potassium (K) is an essential inorganic nutrient needed by plants for their growth and development. The conserved target of rapamycin (TOR) kinase, a well-known nutrition signaling integrator, has crucial roles in regulating growth and development in all eukaryotes. Emerging evidence suggests that TOR is a core regulator of nutrient absorption and utilization in plants. However, it is still unclear whether there is a causative link between the TOR pathway and potassium absorption. Here, we show that the expression of some potassium transporters and channels was regulated by TOR, and the suppression of TOR activity significantly affected potassium uptake in Arabidopsis and potato. Furthermore, we discovered that a Type 2A phosphatase-associated protein of 46 kDa (TAP46), a direct TOR downstream effector, could interact with CBL-interacting protein kinase 23 (CIPK23) in Arabidopsis and potato. In Arabidopsis, the K+ channel AKT1 conducting K+ uptake was significantly regulated by Calcineurin B-like Calcium Sensor Protein 1/9 (CBL1/9)-CIPK23 modules. We found that the cbl1cbl9, cipk23 (lks1-2 and lks1-3), and akt1 mutants were more hyposensitive to the TOR inhibitor than the wild-type, and the TOR inhibitor induced the downregulation of K+ uptake rate in the wild-type more than in these mutants. In addition, the overexpression of CIPK23 could effectively restore the defects in growth and potassium uptake induced by the TOR inhibitors. Thus, our work reveals a link between TOR signaling and CIPK23 and provides new insight into the regulation of potassium uptake in plants.
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Affiliation(s)
- Kexuan Deng
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Wanjing Wang
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Li Feng
- Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 45000, China
| | - Huan Yin
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Fangjie Xiong
- School of Life Sciences, Chongqing University, Chongqing, 401331, China
| | - Maozhi Ren
- School of Life Sciences, Chongqing University, Chongqing, 401331, China; Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 610213, China; Zhengzhou Research Base, State Key Laboratory of Cotton Biology, Zhengzhou University, Zhengzhou, 45000, China.
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A Synthetic Cytokinin Improves Photosynthesis in Rice under Drought Stress by Modulating the Abundance of Proteins Related to Stomatal Conductance, Chlorophyll Contents, and Rubisco Activity. PLANTS 2020; 9:plants9091106. [PMID: 32867335 PMCID: PMC7569833 DOI: 10.3390/plants9091106] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 02/07/2023]
Abstract
Drought susceptible rice cultivar PTT1 (Pathumthani1) was treated with drought (-72 kPa) and CPPU (N-2-(chloro-4-pyridyl)-N-phenyl urea) @ 5 mg/L at tillering and grain-filling stages. Plants were tested for the effect of synthetic cytokinin on the parameters influencing the process of photosynthesis. Exogenous spray of CPPU improved the stomatal conductance of rice leaves, which was severely reduced by drought. The abundance intensities of proteins, associated with the stomatal conductance (ZEP, NCED4, PYL9, PYL10, ABI5, SnRK4, Phot1, and Phot2), were also in agreement with the positive impact of CPPU on the stomatal conductance under drought stress. Among the photosynthetic pigments, Chl b contents were significantly reduced by drought stress, whereas CPPU treated plants retained the normal contents of Chl b under drought stress. Subsequently, we examined the abundance intensities of chlorophyll synthase and HCR proteins, implicated in the biosynthesis of chlorophyll pigments and the conversion of Chl b to Chl a, respectively. The results indicated a drought-mediated suppression of chlorophyll synthase. However, CPPU treated plants retained normal levels of chlorophyll synthase under drought stress. In addition, drought stress induced HCR proteins, which might be the cause for reduced Chl b contents in drought stressed plants. Further, CPPU treatment helped the plants sustain photosynthesis at a normal rate under drought stress, which was comparable with well-watered plants. The results were further confirmed by examining the abundance intensities of two key proteins, RAF1 and Rubisco activase, implicated in the assembly and activation of Rubisco, respectively. CPPU treatment reversed the drought mediated suppression of these proteins at both of the growth stages of rice under drought stress. Based on the results, it can be suggested that synthetic cytokinins help the plants sustain photosynthesis at a normal rate under drought stress by positively influencing the determinants of photosynthesis at a molecular level.
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Klejchová M, Hills A, Blatt MR. Predicting the unexpected in stomatal gas exchange: not just an open-and-shut case. Biochem Soc Trans 2020; 48:881-889. [PMID: 32453378 PMCID: PMC7329339 DOI: 10.1042/bst20190632] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 12/22/2022]
Abstract
Plant membrane transport, like transport across all eukaryotic membranes, is highly non-linear and leads to interactions with characteristics so complex that they defy intuitive understanding. The physiological behaviour of stomatal guard cells is a case in point in which, for example, mutations expected to influence stomatal closing have profound effects on stomatal opening and manipulating transport across the vacuolar membrane affects the plasma membrane. Quantitative mathematical modelling is an essential tool in these circumstances, both to integrate the knowledge of each transport process and to understand the consequences of their manipulation in vivo. Here, we outline the OnGuard modelling environment and its use as a guide to predicting the emergent properties arising from the interactions between non-linear transport processes. We summarise some of the recent insights arising from OnGuard, demonstrate its utility in interpreting stomatal behaviour, and suggest ways in which the OnGuard environment may facilitate 'reverse-engineering' of stomata to improve water use efficiency and carbon assimilation.
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Affiliation(s)
- Martina Klejchová
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow G12 8QQ, U.K
| | - Adrian Hills
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow G12 8QQ, U.K
| | - Michael R. Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow G12 8QQ, U.K
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Abstract
Plants balance their competing requirements for growth and stress tolerance via a sophisticated regulatory circuitry that controls responses to the external environments. We have identified a plant-specific gene, COST1 (constitutively stressed 1), that is required for normal plant growth but negatively regulates drought resistance by influencing the autophagy pathway. An Arabidopsis thaliana cost1 mutant has decreased growth and increased drought tolerance, together with constitutive autophagy and increased expression of drought-response genes, while overexpression of COST1 confers drought hypersensitivity and reduced autophagy. The COST1 protein is degraded upon plant dehydration, and this degradation is reduced upon treatment with inhibitors of the 26S proteasome or autophagy pathways. The drought resistance of a cost1 mutant is dependent on an active autophagy pathway, but independent of other known drought signaling pathways, indicating that COST1 acts through regulation of autophagy. In addition, COST1 colocalizes to autophagosomes with the autophagosome marker ATG8e and the autophagy adaptor NBR1, and affects the level of ATG8e protein through physical interaction with ATG8e, indicating a pivotal role in direct regulation of autophagy. We propose a model in which COST1 represses autophagy under optimal conditions, thus allowing plant growth. Under drought, COST1 is degraded, enabling activation of autophagy and suppression of growth to enhance drought tolerance. Our research places COST1 as an important regulator controlling the balance between growth and stress responses via the direct regulation of autophagy.
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Chen G, Chen Q, Qi K, Xie Z, Yin H, Wang P, Wang R, Huang Z, Zhang S, Wang L, Wu J. Identification of Shaker K + channel family members in Rosaceae and a functional exploration of PbrKAT1. PLANTA 2019; 250:1911-1925. [PMID: 31523779 DOI: 10.1007/s00425-019-03275-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 09/06/2019] [Indexed: 05/20/2023]
Abstract
PbrKAT1, which is inhibited by external Na+ in Xenopus laevis oocytes, is characterized as encoding a typical inward rectifying channel that is mainly expressed in guard cells. Potassium (K+) is the most abundant cation in plant cells necessary for plant growth and development. The uptake and transport of K+ are mainly completed through transporters and channels, and the Shaker family genes are the most studied K+ channels in plants. However, there is far less information about this family in Rosaceae species. We performed a genome-wide analysis and identified Shaker K+ channel gene family members in Rosaceae. We cloned and characterized a Shaker K+ channel KAT1 from pear (Pyrus × bretschneideri). In total, 36 Shaker K+ channel genes were identified from Rosaceae species and were classified into five subgroups based on structural characteristics and a phylogenetic analysis. Whole-genome and dispersed duplications were the primary forces underlying Shaker K+ channel gene family expansion in Rosaceae, and purifying selection played a key role in the evolution of Shaker K+ channel genes. β-Glucuronidase and qRT-PCR assays revealed that PbrKAT1 was mainly expressed in leaves, especially in guard cells. PbrKAT1 displayed a typical inward-rectifying current when expressed in Xenopus laevis oocytes. The activity of PbrKAT1 was inhibited by external sodium ions, possibly playing an important role in the regulation of salt tolerance in pear. These results provide valuable information on evolution, expression and functions of the Shaker K+ channel gene family in plants.
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Affiliation(s)
- Guodong Chen
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qian Chen
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Kaijie Qi
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhihua Xie
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Hao Yin
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Peng Wang
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Runze Wang
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Zhi Huang
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Shaoling Zhang
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China
| | - Li Wang
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Juyou Wu
- Center of Pear Engineering Technology Research, State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
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Villette J, Cuéllar T, Zimmermann SD, Verdeil JL, Gaillard I. Unique features of the grapevine VvK5.1 channel support novel functions for outward K+ channels in plants. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6181-6193. [PMID: 31327013 PMCID: PMC6859719 DOI: 10.1093/jxb/erz341] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 07/15/2019] [Indexed: 05/04/2023]
Abstract
Grapevine (Vitis vinifera L.), one of the most important fruit crops, is a model plant for studying the physiology of fleshy fruits. Here, we report on the characterization of a new grapevine Shaker-type K+ channel, VvK5.1. Phylogenetic analysis revealed that VvK5.1 belongs to the SKOR-like subfamily. Our functional characterization of VvK5.1 in Xenopus oocytes confirms that it is an outwardly rectifying K+ channel that displays strict K+ selectivity. Gene expression level analyses by real-time quantitative PCR showed that VvK5.1 expression was detected in berries, roots, and flowers. In contrast to its Arabidopsis thaliana counterpart that is involved in K+ secretion in the root pericycle, allowing root to shoot K+ translocation, VvK5.1 expression territory is greatly enlarged. Using in situ hybridization we showed that VvK5.1 is expressed in the phloem and perivascular cells of berries and in flower pistil. In the root, in addition to being expressed in the root pericycle like AtSKOR, a strong expression of VvK5.1 is detected in small cells facing the xylem that are involved in lateral root formation. This fine and selective expression pattern of VvK5.1 at the early stage of lateral root primordia supports a role for outward channels to switch on cell division initiation.
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Affiliation(s)
- Jérémy Villette
- BPMP, Université Montpellier, CNRS, INRA, SupAgro, Montpellier, France
| | - Teresa Cuéllar
- CIRAD, UMR AGAP, F-34398 Montpellier, France
- Université Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | | | - Jean-Luc Verdeil
- CIRAD, UMR AGAP, F-34398 Montpellier, France
- Université Montpellier, CIRAD, INRA, Montpellier SupAgro, Montpellier, France
| | - Isabelle Gaillard
- BPMP, Université Montpellier, CNRS, INRA, SupAgro, Montpellier, France
- Correspondence:
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Sustr M, Soukup A, Tylova E. Potassium in Root Growth and Development. PLANTS (BASEL, SWITZERLAND) 2019; 8:E435. [PMID: 31652570 PMCID: PMC6843428 DOI: 10.3390/plants8100435] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/18/2019] [Accepted: 10/19/2019] [Indexed: 02/06/2023]
Abstract
Potassium is an essential macronutrient that has been partly overshadowed in root science by nitrogen and phosphorus. The current boom in potassium-related studies coincides with an emerging awareness of its importance in plant growth, metabolic functions, stress tolerance, and efficient agriculture. In this review, we summarized recent progress in understanding the role of K+ in root growth, development of root system architecture, cellular functions, and specific plant responses to K+ shortage. K+ transport is crucial for its physiological role. A wide range of K+ transport proteins has developed during evolution and acquired specific functions in plants. There is evidence linking K+ transport with cell expansion, membrane trafficking, auxin homeostasis, cell signaling, and phloem transport. This places K+ among important general regulatory factors of root growth. K+ is a rather mobile element in soil, so the absence of systemic and localized root growth response has been accepted. However, recent research confirms both systemic and localized growth response in Arabidopsis thaliana and highlights K+ uptake as a crucial mechanism for plant stress response. K+-related regulatory mechanisms, K+ transporters, K+ acquisition efficiency, and phenotyping for selection of K+ efficient plants/cultivars are highlighted in this review.
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Affiliation(s)
- Marek Sustr
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic.
| | - Ales Soukup
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic.
| | - Edita Tylova
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Vinicna 5, 128 44 Prague 2, Czech Republic.
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41
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Locascio A, Andrés-Colás N, Mulet JM, Yenush L. Saccharomyces cerevisiae as a Tool to Investigate Plant Potassium and Sodium Transporters. Int J Mol Sci 2019; 20:E2133. [PMID: 31052176 PMCID: PMC6539216 DOI: 10.3390/ijms20092133] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/26/2019] [Accepted: 04/29/2019] [Indexed: 12/20/2022] Open
Abstract
Sodium and potassium are two alkali cations abundant in the biosphere. Potassium is essential for plants and its concentration must be maintained at approximately 150 mM in the plant cell cytoplasm including under circumstances where its concentration is much lower in soil. On the other hand, sodium must be extruded from the plant or accumulated either in the vacuole or in specific plant structures. Maintaining a high intracellular K+/Na+ ratio under adverse environmental conditions or in the presence of salt is essential to maintain cellular homeostasis and to avoid toxicity. The baker's yeast, Saccharomyces cerevisiae, has been used to identify and characterize participants in potassium and sodium homeostasis in plants for many years. Its utility resides in the fact that the electric gradient across the membrane and the vacuoles is similar to plants. Most plant proteins can be expressed in yeast and are functional in this unicellular model system, which allows for productive structure-function studies for ion transporting proteins. Moreover, yeast can also be used as a high-throughput platform for the identification of genes that confer stress tolerance and for the study of protein-protein interactions. In this review, we summarize advances regarding potassium and sodium transport that have been discovered using the yeast model system, the state-of-the-art of the available techniques and the future directions and opportunities in this field.
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Affiliation(s)
- Antonella Locascio
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
| | - Nuria Andrés-Colás
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
| | - José Miguel Mulet
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
| | - Lynne Yenush
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
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Luu K, Rajagopalan N, Ching JCH, Loewen MC, Loewen ME. The malate-activated ALMT12 anion channel in the grass Brachypodium distachyon is co-activated by Ca 2+/calmodulin. J Biol Chem 2019; 294:6142-6156. [PMID: 30770467 PMCID: PMC6463695 DOI: 10.1074/jbc.ra118.005301] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 02/12/2019] [Indexed: 01/09/2023] Open
Abstract
In plants, strict regulation of stomatal pores is critical for modulation of CO2 fixation and transpiration. Under certain abiotic and biotic stressors, pore closure is initiated through anionic flux, with calcium (Ca2+) playing a central role. The aluminum-activated malate transporter 12 (ALMT12) is a malate-activated, voltage-dependent member of the aluminum-activated malate transporter family that has been implicated in anionic flux from guard cells controlling the stomatal aperture. Herein, we report the characterization of the regulatory mechanisms mediating channel activities of an ALMT from the grass Brachypodium distachyon (BdALMT12) that has the highest sequence identity to Arabidopsis thaliana ALMT12. Electrophysiological studies in a heterologous cell system confirmed that this channel is malate- and voltage-dependent. However, this was shown to be true only in the presence of Ca2+ Although a general kinase inhibitor increased the current density of BdALMT12, a calmodulin (CaM) inhibitor reduced the Ca2+-dependent channel activation. We investigated the physiological relevance of the CaM-based regulation in planta, where stomatal closure, induced by exogenous Ca2+ ionophore and malate, was shown to be inhibited by exogenous application of a CaM inhibitor. Subsequent analyses revealed that the double substitutions R335A/R338A and R335A/K342A, within a predicted BdALMT12 CaM-binding domain (CBD), also decreased the channels' ability to activate. Using isothermal titration calorimetry and CBD-mimetic peptides, as well as CaM-agarose affinity pulldown of full-length recombinant BdALMT12, we confirmed the physical interaction between the CBD and CaM. Together, these findings support a co-regulatory mechanism of BdALMT12 activation by malate, and Ca2+/CaM, emphasizing that a complex regulatory network modulates BdALMT12 activity.
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Affiliation(s)
- Khanh Luu
- From the Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 1B8
| | | | - John C H Ching
- From the Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 1B8
| | - Michele C Loewen
- the National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9; the National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada; the Department of Biomedical and Molecular Sciences, Queens University, Kingston, Ontario K7L 0N6, Canada.
| | - Matthew E Loewen
- From the Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan S7N 1B8
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Gao YQ, Wu WH, Wang Y. Electrophysiological Identification and Activity Analyses of Plasma Membrane K+ Channels in Maize Guard Cells. PLANT & CELL PHYSIOLOGY 2019; 60:765-777. [PMID: 30590755 DOI: 10.1093/pcp/pcy242] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Accepted: 12/19/2018] [Indexed: 05/11/2023]
Abstract
Stomatal movement, which plays an essential role in plant transpiration and photosynthesis, is controlled by ion channels that mediate K+ and anion fluxes across the plasma membrane (PM) of guard cells. These channels in dicots are accurately regulated by various physiological factors, such as pH, abscisic acid (ABA) and Ca2+; however, the data in monocots are limited. Here the whole-cell patch-clamping technique was applied to analyze the properties and regulations of PM K+ channels in maize guard cells. The results indicated that the hyperpolarization-activated inward-rectifying channels were highly K+-selective. These inward K+ (Kin) channels were sensitive to extracellular K+. Their slope factor (S) decreased when the apoplastic K+ concentration decline, causing a positive shift of the half-activation potential (V1/2). Their activities were promoted by apoplastic acidification but inhibited by apoplastic and cytosolic alkalization. Nevertheless, the outward K+ (Kout) channel activities were uniquely promoted by cytosolic alkalization. Both apoplastic and cytosolic ABA inhibited Kin channels independent of cytosolic Ca2+ ([Ca2+]cyt). And two Ca2+-dependent mechanisms with different Ca2+ affinities may mediate resting- and high-[Ca2+]cyt-induced inhibition on Kin channels, respectively. However, resting [Ca2+]cyt impaired the inhibition of Kin channels induced by apoplastic ABA, not cytosolic ABA. Furthermore, the result that high [Ca2+]cyt attenuated ABA-induced inhibition highlighted the importance of [Ca2+]cyt for Kin channel regulation. There may exist a Ca2+-dependent regulation of the Ca2+-independent ABA signaling pathways for Kin channel inhibition. These results provided an electrophysiological view of the multiple level regulations of PM K+ channel activities and kinetics in maize guard cells.
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Affiliation(s)
- Yong-Qiang Gao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China
| | - Wei-Hua Wu
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China
| | - Yi Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing, China
- Center for Crop Functional Genomics and Molecular Breeding, China Agricultural University, Beijing, China
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The Complex Fine-Tuning of K⁺ Fluxes in Plants in Relation to Osmotic and Ionic Abiotic Stresses. Int J Mol Sci 2019; 20:ijms20030715. [PMID: 30736441 PMCID: PMC6387338 DOI: 10.3390/ijms20030715] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 01/17/2019] [Accepted: 01/29/2019] [Indexed: 12/19/2022] Open
Abstract
As the main cation in plant cells, potassium plays an essential role in adaptive responses, especially through its involvement in osmotic pressure and membrane potential adjustments. K+ homeostasis must, therefore, be finely controlled. As a result of different abiotic stresses, especially those resulting from global warming, K⁺ fluxes and plant distribution of this ion are disturbed. The hormone abscisic acid (ABA) is a key player in responses to these climate stresses. It triggers signaling cascades that ultimately lead to modulation of the activities of K⁺ channels and transporters. After a brief overview of transcriptional changes induced by abiotic stresses, this review deals with the post-translational molecular mechanisms in different plant organs, in Arabidopsis and species of agronomical interest, triggering changes in K⁺ uptake from the soil, K⁺ transport and accumulation throughout the plant, and stomatal regulation. These modifications involve phosphorylation/dephosphorylation mechanisms, modifications of targeting, and interactions with regulatory partner proteins. Interestingly, many signaling pathways are common to K⁺ and Cl-/NO3- counter-ion transport systems. These cross-talks are also addressed.
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Saito S, Uozumi N. Guard Cell Membrane Anion Transport Systems and Their Regulatory Components: An Elaborate Mechanism Controlling Stress-Induced Stomatal Closure. PLANTS 2019; 8:plants8010009. [PMID: 30609843 PMCID: PMC6359458 DOI: 10.3390/plants8010009] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/19/2018] [Accepted: 12/16/2018] [Indexed: 02/07/2023]
Abstract
When plants are exposed to drastic environmental changes such as drought, salt or bacterial invasion, rapid stomatal movement confers tolerance to these stresses. This process involves a variety of guard cell expressed ion channels and their complex regulation network. Inward K+ channels mainly function in stomatal opening. On the other hand, guard cell anion channels play a crucial role in the closing of stomata, which is vital in terms of preventing water loss and bacterial entrance. Massive progress has been made on the research of these anion channels in the last decade. In this review, we focus on the function and regulation of Arabidopsis guard cell anion channels. Starting from SLAC1, a main contributor of stomatal closure, members of SLAHs (SLAC1 homologues), AtNRTs (Nitrate transporters), AtALMTs (Aluminum-activated malate transporters), ABC transporters, AtCLCs (Chloride channels), DTXs (Detoxification efflux carriers), SULTRs (Sulfate transporters), and their regulator components are reviewed. These membrane transport systems are the keys to maintaining cellular ion homeostasis against fluctuating external circumstances.
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Affiliation(s)
- Shunya Saito
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan.
| | - Nobuyuki Uozumi
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan.
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Geilfus CM, Lan J, Carpentier S. Dawn regulates guard cell proteins in Arabidopsis thaliana that function in ATP production from fatty acid beta-oxidation. PLANT MOLECULAR BIOLOGY 2018; 98:525-543. [PMID: 30392160 DOI: 10.1007/s11103-018-0794-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 10/28/2018] [Indexed: 06/08/2023]
Abstract
Based on the nature of the proteins that are altered in abundance, we conclude that guard cells switch their energy source from fatty acid metabolism to chloroplast activity, at the onset of dawn. During stomatal opening at dawn, evidence was recently presented for a breakdown and liquidation of stored triacylglycerols in guard cells to supply ATP for use in stomatal opening. However, proteome changes that happen in the guard cells during dawn were until now poorly understood. Bad accessibility to pure and intact guard cell samples can be considered as the primary reason behind this lack of knowledge. To overcome these technical constraints, epidermal guard cell samples with ruptured pavement cells were isolated at 1 h pre-dawn, 15 min post-dawn and 1 h post-dawn from Arabidopsis thaliana. Proteomic changes were analysed by ultra-performance-liquid-chromatography-mass-spectrometry. With 994 confidently identified proteins, we present the first analysis of the A. thaliana guard cell proteome that is not influenced by side effects of guard cell protoplasting. Data are available via ProteomeXchange with identifier PXD009918. By elucidating the identities of enzymes that change in abundance by the transition from dark to light, we corroborate the hypothesis that respiratory ATP production for stomatal opening results from fatty acid beta-oxidation. Moreover, we identified many proteins that were never reported in the context of guard cell biology. Among them are proteins that might play a role in signalling or circadian rhythm.
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Affiliation(s)
- Christoph-Martin Geilfus
- Division of Controlled Environment Horticulture, Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-University of Berlin, Albrecht-Thaer-Weg 1, 14195, Berlin, Germany.
- Proteomics Core Facility, SYBIOMA, KU Leuven, O&N II Herestraat 49 - bus 901, 3000, Leuven, Belgium.
| | - Jue Lan
- School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol, BS8 1TQ, UK
| | - Sebastien Carpentier
- Proteomics Core Facility, SYBIOMA, KU Leuven, O&N II Herestraat 49 - bus 901, 3000, Leuven, Belgium
- Division of Crop Biotechnics, Department of Biosystems, KU Leuven, Willem de Croylaan 42 - Box 2455, 3001, Leuven, Belgium
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A Cyclic Nucleotide-Gated Channel, HvCNGC2-3, Is Activated by the Co-Presence of Na⁺ and K⁺ and Permeable to Na⁺ and K⁺ Non-Selectively. PLANTS 2018; 7:plants7030061. [PMID: 30049942 PMCID: PMC6161278 DOI: 10.3390/plants7030061] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/09/2018] [Accepted: 07/24/2018] [Indexed: 12/21/2022]
Abstract
Cyclic nucleotide-gated channels (CNGCs) have been postulated to contribute significantly in plant development and stress resistance. However, their electrophysiological properties remain poorly understood. Here, we characterized barley CNGC2-3 (HvCNGC2-3) by the two-electrode voltage-clamp technique in the Xenopus laevis oocyte heterologous expression system. Current was not observed in X. laevis oocytes injected with HvCNGC2-3 complementary RNA (cRNA) in a bathing solution containing either Na+ or K+ solely, even in the presence of 8-bromoadenosine 3′,5′-cyclic monophosphate (8Br-cAMP) or 8-bromoguanosine 3′,5′-cyclic monophosphate (8Br-cGMP). A weakly voltage-dependent slow hyperpolarization-activated ion current was observed in the co-presence of Na+ and K+ in the bathing solution and in the presence of 10 µM 8Br-cAMP, but not 8Br-cGMP. Permeability ratios of HvCNGC2-3 to K+, Na+ and Cl− were determined as 1:0.63:0.03 according to reversal-potential analyses. Amino-acid replacement of the unique ion-selective motif of HvCNGC2-3, AQGL, with the canonical motif, GQGL, resulted in the abolition of the current. This study reports a unique two-ion-dependent activation characteristic of the barley CNGC, HvCNGC2-3.
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Wang X, Wang Y, Wang L, Liu H, Zhang B, Cao Q, Liu X, Bi S, Lv Y, Wang Q, Zhang S, He M, Tang S, Yao S, Wang C. Arabidopsis PCaP2 Functions as a Linker Between ABA and SA Signals in Plant Water Deficit Tolerance. FRONTIERS IN PLANT SCIENCE 2018; 9:578. [PMID: 29868051 PMCID: PMC5962825 DOI: 10.3389/fpls.2018.00578] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/13/2018] [Indexed: 05/29/2023]
Abstract
Water stress has a major influence on plant growth, development, and productivity. However, the cross-talk networks involved in drought tolerance are not well understood. Arabidopsis PCaP2 is a plasma membrane-associated Ca2+-binding protein. In this study, we employ qRT-PCR and β-glucuronidase (GUS) histochemical staining to demonstrate that PCaP2 expression was strongly induced in roots, cotyledons, true leaves, lateral roots, and whole plants under water deficit conditions. Compared with the wild type (WT) plants, PCaP2-overexpressing (PCaP2-OE) plants displayed enhanced water deficit tolerance in terms of seed germination, seedling growth, and plant survival status. On the contrary, PCaP2 mutation and reduction via PCaP2-RNAi rendered plants more sensitive to water deficit. Furthermore, PCaP2-RNAi and pcap2 seedlings showed shorter root hairs and lower relative water content compared to WT under normal conditions and these phenotypes were exacerbated under water deficit. Additionally, the expression of PCaP2 was strongly induced by exogenous abscisic acid (ABA) and salicylic acid (SA) treatments. PCaP2-OE plants showed insensitive to exogenous ABA and SA treatments, in contrast to the susceptible phenotypes of pcap2 and PCaP2-RNAi. It is well-known that SNF1-related kinase 2s (SnRK2s) and pathogenesis-related (PRs) are major factors that influence plant drought tolerance by ABA- and SA-mediated pathways, respectively. Interestingly, PCaP2 positively regulated the expression of drought-inducible genes (RD29A, KIN1, and KIN2), ABA-mediated drought responsive genes (SnRK2.2, -2.3, -2.6, ABF1, -2, -3, -4), and SA-mediated drought responsive genes (PR1, -2, -5) under water deficit, ABA, or SA treatments. Taken together, our results showed that PCaP2 plays an important and positive role in Arabidopsis water deficit tolerance by involving in response to both ABA and SA signals and regulating root hair growth. This study provides novel insights into the underlying cross-talk mechanisms of plants in response to water deficit stress.
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Affiliation(s)
- Xianling Wang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Yu Wang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Lu Wang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Huan Liu
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Bing Zhang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Qijiang Cao
- Department of Medicine, HE University School of Clinical Medicine, Shenyang, China
| | - Xinyu Liu
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Shuangtian Bi
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Yanling Lv
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
- Vegetable Research Institute of Liaoning Academy of Agricultural Sciences, Shenyang, China
| | - Qiuyang Wang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Shaobin Zhang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Ming He
- Vegetable Research Institute of Liaoning Academy of Agricultural Sciences, Shenyang, China
| | - Shuang Tang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Shuo Yao
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Che Wang
- College of Biological Science and Biotechnology, Shenyang Agricultural University, Shenyang, China
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Jin M, Guo M, Yue G, Li J, Yang S, Zhao P, Su Y. An unusual strategy of stomatal control in the desert shrub Ammopiptanthus mongolicus. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 125:13-26. [PMID: 29413627 DOI: 10.1016/j.plaphy.2018.01.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/05/2018] [Accepted: 01/22/2018] [Indexed: 05/27/2023]
Abstract
Water deficit is one of the main environmental constraints that limit plant growth. Accordingly, plants evoke rather complex strategies to respond and/or acclimate to such frustrating circumstances. Due to insufficient understandings of acclimatory mechanisms of plants' tolerance to persistent water deficit, a desert shrub of an ancient origin, Ammopiptanthus mongolicus, has recently attracted growing attentions. Differed from Arabidopsis, the opening of stomata of A. mongolicus is constrained by low external K+ concentration of the guard cells. Although as a general consequence, a raised level of ABA is also induced in A. mongolicus following water deficit, this does not accordingly result in efficient stomatal closure. In consistent with this phenomenon, the expression of genes coding for the negative regulators of the ABA signaling cascade-the type 2C protein phosphatases (PP2Cs) are notably induced, whereas the transcription of the downstream SnRK2 protein kinase genes or the destination ion fluxing channel genes remain almost unaffected under water deficit treatments. Therefore, in term of stomatal control in response to water deficit, A. mongolicus seemingly employs an unusual strategy: a constrained stomatal opening controlled by extracellular K+ concentrations rather than a prompt stomatal closure triggered by ABA-induced signaling pathway. Additionally, an acute accumulation of proline is induced by water deficit which may partly compromise the activation of antioxidant enzymes in A. mongolicus. Such strategy of stomatal control found in A. mongolicus may in certain extents, reflect the acclimatory divergence for plants' coping with persistent stress of water deficit.
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Affiliation(s)
- Man Jin
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Manyuan Guo
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Guangzhen Yue
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China
| | - Junlin Li
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China; Institute of Botany, Jiangsu Province and Chinese Academy of Sciences, Nanjing, China
| | - Shunying Yang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China
| | - Pengshu Zhao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Yanhua Su
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, China.
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Gao YQ, Wu WH, Wang Y. The K + channel KZM2 is involved in stomatal movement by modulating inward K + currents in maize guard cells. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:662-675. [PMID: 28891257 DOI: 10.1111/tpj.13712] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 08/28/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Stomata are the major gates in plant leaf that allow water and gas exchange, which is essential for plant transpiration and photosynthesis. Stomatal movement is mainly controlled by the ion channels and transporters in guard cells. In Arabidopsis, the inward Shaker K+ channels, such as KAT1 and KAT2, are responsible for stomatal opening. However, the characterization of inward K+ channels in maize guard cells is limited. In the present study, we identified two KAT1-like Shaker K+ channels, KZM2 and KZM3, which were highly expressed in maize guard cells. Subcellular analysis indicated that KZM2 and KZM3 can localize at the plasma membrane. Electrophysiological characterization in HEK293 cells revealed that both KZM2 and KZM3 were inward K+ (Kin ) channels, but showing distinct channel kinetics. When expressed in Xenopus oocytes, only KZM3, but not KZM2, can mediate inward K+ currents. However, KZM2 can interact with KZM3 forming heteromeric Kin channel. In oocytes, KZM2 inhibited KZM3 channel conductance and negatively shifted the voltage dependence of KZM3. The activation of KZM2-KZM3 heteromeric channel became slower than the KZM3 channel. Patch-clamping results showed that the inward K+ currents of maize guard cells were significantly increased in the KZM2 RNAi lines. In addition, the RNAi lines exhibited faster stomatal opening after light exposure. In conclusion, the presented results demonstrate that KZM2 functions as a negative regulator to modulate the Kin channels in maize guard cells. KZM2 and KZM3 may form heteromeric Kin channel and control stomatal opening in maize.
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Affiliation(s)
- Yong-Qiang Gao
- State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Wei-Hua Wu
- State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, 100193, China
| | - Yi Wang
- State Key Laboratory of Plant Physiology and Biochemistry (SKLPPB), College of Biological Sciences, China Agricultural University, Beijing, 100193, China
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