1
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Nieves-Cordones M, Amo J, Hurtado-Navarro L, Martínez-Martínez A, Martínez V, Rubio F. Inhibition of SlSKOR by SlCIPK23-SlCBL1/9 uncovers CIPK-CBL-target network rewiring in land plants. THE NEW PHYTOLOGIST 2023; 238:2495-2511. [PMID: 36967582 DOI: 10.1111/nph.18910] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 03/19/2023] [Indexed: 05/19/2023]
Abstract
Transport of K+ to the xylem is a key process in the mineral nutrition of the shoots. Although CIPK-CBL complexes have been widely shown to regulate K+ uptake transport systems, no information is available about the xylem ones. Here, we studied the physiological roles of the voltage-gated K+ channel SlSKOR and its regulation by the SlCIPK23-SlCBL1/9 complexes in tomato plants. We phenotyped gene-edited slskor and slcipk23 tomato knockout mutants and carried out two-electrode voltage-clamp (TEVC) and BiFC assays in Xenopus oocytes as key approaches. SlSKOR was preferentially expressed in the root stele and was important not only for K+ transport to shoots but also, indirectly, for that of Ca2+ , Mg2+ , Na+ , NO3 - , and Cl- . Surprisingly, the SlCIPK23-SlCBL1/9 complexes turned out to be negative regulators of SlSKOR. Inhibition of SlSKOR by SlCIPK23-SlCBL1/9 was observed in Xenopus oocytes and tomato plants. Regulation of SKOR-like channels by CIPK23-CBL1 complexes was also present in Medicago, grapevine, and lettuce but not in Arabidopsis and saltwater cress. Our results provide a molecular framework for coordinating root K+ uptake and its translocation to the shoot by SlCIPK23-SlCBL1/9 in tomato plants. Moreover, they evidenced that CIPK-CBL-target networks have evolved differently in land plants.
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Affiliation(s)
- Manuel Nieves-Cordones
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Murcia, 30100, Spain
| | - Jesús Amo
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Murcia, 30100, Spain
| | - Laura Hurtado-Navarro
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Murcia, 30100, Spain
| | - Almudena Martínez-Martínez
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Murcia, 30100, Spain
| | - Vicente Martínez
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Murcia, 30100, Spain
| | - Francisco Rubio
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura-CSIC, Murcia, 30100, Spain
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2
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Yang M, He J, Sun Z, Li Q, Cai J, Zhou Q, Wollenweber B, Jiang D, Wang X. Drought priming mechanisms in wheat elucidated by in-situ determination of dynamic stomatal behavior. FRONTIERS IN PLANT SCIENCE 2023; 14:1138494. [PMID: 36875605 PMCID: PMC9983753 DOI: 10.3389/fpls.2023.1138494] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 02/07/2023] [Indexed: 06/18/2023]
Abstract
Stomata play a critical role in balancing photosynthesis and transpiration, which are essential processes for plant growth, especially in response to abiotic stress. Drought priming has been shown to improve drought tolerance. Lots of studies have been done with the response of stomatal behavior to drought stress. However, how the stomatal dynamic movement in intact wheat plants response to drought priming process is not known. Here, a portable microscope was used to take microphotographs in order to in-stiu determination of stomatal behavior. Non-invasive micro-test technology was used for measurements of guard cell K+, H+ and Ca2+ fluxes. Surprisingly, the results found that primed plants close stomatal much faster under drought stress, and reopening the stomatal much quicker under recovery, in relation to non-primed plants. Compared with non-primed plants, primed plants showed higher accumulation of ABA and Ca2+ influx rate in guard cells under drought stress. Furthermore, genes encoding anion channels were higher expressed and K+ outward channels activated, leading to enhanced K+ efflux, resulting in faster stomatal closure in primed plants than non-primed plants. During recovery, both guard cell ABA and Ca2+ influx of primed plants were found to be significantly reducing K+ efflux and accelerating stomatal reopening. Collectively, a portable non-invasive stomatal observation of wheat found that priming promoted faster stomatal closure under drought stress and faster reopening during post-drought recovery in relation to non-primed plants, thereby enhancing overall drought tolerance.
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Affiliation(s)
- Mengxiang Yang
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | - Jiawei He
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | - Zhuangzhuang Sun
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | - Qing Li
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | - Jian Cai
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | - Qin Zhou
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | | | - Dong Jiang
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
| | - Xiao Wang
- Key Laboratory of Crop Ecophysiology, Ministry of Agriculture, National Technique Innovation Center for Regional Wheat Production, Nanjing Agricultural University, Nanjing, China
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3
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Mostofa MG, Rahman MM, Ghosh TK, Kabir AH, Abdelrahman M, Rahman Khan MA, Mochida K, Tran LSP. Potassium in plant physiological adaptation to abiotic stresses. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2022; 186:279-289. [PMID: 35932652 DOI: 10.1016/j.plaphy.2022.07.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 06/30/2022] [Accepted: 07/09/2022] [Indexed: 05/02/2023]
Abstract
Potassium (K) is an integral part of plant nutrition, playing essential roles in plant growth and development. Despite its abundance in soils, the limitedly available form of K ion (K+) for plant uptake is a critical factor for agricultural production. Plants have evolved complex transport systems to maintain appropriate K+ levels in tissues under changing environmental conditions. Adequate stimulation and coordinated actions of multiple K+-channels and K+-transporters are required for nutrient homeostasis, reproductive growth, cellular signaling and stress adaptation responses in plants. Various contemporary studies revealed that K+-homeostasis plays a substantial role in plant responses and tolerance to abiotic stresses. The beneficial effects of K+ in plant responses to abiotic stresses include its roles in physiological and biochemical mechanisms involved in photosynthesis, osmoprotection, stomatal regulation, water-nutrient absorption, nutrient translocation and enzyme activation. Over the last decade, we have seen considerable breakthroughs in K research, owing to the advances in omics technologies. In this aspect, omics investigations (e.g., transcriptomics, metabolomics, and proteomics) in systems biology manner have broadened our understanding of how K+ signals are perceived, conveyed, and integrated for improving plant physiological resilience to abiotic stresses. Here, we update on how K+-uptake and K+-distribution are regulated under various types of abiotic stress. We discuss the effects of K+ on several physiological functions and the interaction of K+ with other nutrients to improve plant potential against abiotic stress-induced adverse consequences. Understanding of how K+ orchestrates physiological mechanisms and contributes to abiotic stress tolerance in plants is essential for practicing sustainable agriculture amidst the climate crisis in global agriculture.
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Affiliation(s)
- Mohammad Golam Mostofa
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA.
| | - Md Mezanur Rahman
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA
| | - Totan Kumar Ghosh
- Department of Crop Botany, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh
| | | | | | - Md Arifur Rahman Khan
- Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh
| | - Keiichi Mochida
- Bioproductivity Informatics Research Team, RIKEN Center for Sustainable Resource Science, Yokohama 230-0045, Japan; Microalgae Production Control Technology Laboratory, RIKEN Baton Zone Program, Yokohama 230-0045, Japan; Kihara Institute for Biological Research, Yokohama City University, Yokohama 230-0045, Japan; School of Information and Data Sciences, Nagasaki University, Nagasaki 852-8521, Japan
| | - Lam-Son Phan Tran
- Institute of Genomics for Crop Abiotic Stress Tolerance, Department of Plant and Soil Science, Texas Tech University, Lubbock, TX 79409, USA; Institute of Research and Development, Duy Tan University, 03 Quang Trung, Da Nang 550000, Vietnam.
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4
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Gámez-Arjona FM, Sánchez-Rodríguez C, Montesinos JC. The root apoplastic pH as an integrator of plant signaling. FRONTIERS IN PLANT SCIENCE 2022; 13:931979. [PMID: 36082302 PMCID: PMC9448249 DOI: 10.3389/fpls.2022.931979] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/26/2022] [Indexed: 06/15/2023]
Abstract
Plant nutrition, growth, and response to environmental stresses are pH-dependent processes that are regulated at the apoplastic and subcellular levels. The root apoplastic pH is especially sensitive to external cues and can also be modified by intracellular inputs, such as hormonal signaling. Optimal crosstalk of the mechanisms involved in the extent and span of the apoplast pH fluctuations promotes plant resilience to detrimental biotic and abiotic factors. The fact that variations in local pHs are a standard mechanism in different signaling pathways indicates that the pH itself can be the pivotal element to provide a physiological context to plant cell regions, allowing a proportional reaction to different situations. This review brings a collective vision of the causes that initiate root apoplastic pHs variations, their interaction, and how they influence root response outcomes.
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5
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Al-Younis I, Moosa B, Kwiatkowski M, Jaworski K, Wong A, Gehring C. Functional Crypto-Adenylate Cyclases Operate in Complex Plant Proteins. FRONTIERS IN PLANT SCIENCE 2021; 12:711749. [PMID: 34456950 PMCID: PMC8387589 DOI: 10.3389/fpls.2021.711749] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Accepted: 07/21/2021] [Indexed: 05/08/2023]
Abstract
Adenylyl cyclases (ACs) and their catalytic product cAMP are regulatory components of many plant responses. Here, we show that an amino acid search motif based on annotated adenylate cyclases (ACs) identifies 12 unique Arabidopsis thaliana candidate ACs, four of which have a role in the biosynthesis of the stress hormone abscisic acid (ABA). One of these, the 9-cis-epoxycarotenoid dioxygenase (NCED3 and At3g14440), was identified by sequence and structural analysis as a putative AC and then tested experimentally with two different methods. Given that the in vitro activity is low (fmoles cAMP pmol-1 protein min-1), but highly reproducible, we term the enzyme a crypto-AC. Our results are consistent with a role for ACs with low activities in multi-domain moonlighting proteins that have at least one other distinct molecular function, such as catalysis or ion channel activation. We propose that crypto-ACs be examined from the perspective that considers their low activities as an innate feature of regulatory ACs embedded within multi-domain moonlighting proteins. It is therefore conceivable that crypto-ACs form integral components of complex plant proteins participating in intra-molecular regulatory mechanisms, and in this case, potentially linking cAMP to ABA synthesis.
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Affiliation(s)
- Inas Al-Younis
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Basem Moosa
- Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Mateusz Kwiatkowski
- Chair of Plant Physiology and Biotechnology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Krzysztof Jaworski
- Chair of Plant Physiology and Biotechnology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University in Toruń, Toruń, Poland
| | - Aloysius Wong
- Department of Biology, College of Science and Technology, Wenzhou-Kean University, Wenzhou, China
- Zhejiang Bioinformatics International Science and Technology Cooperation Center of Wenzhou-Kean University, Wenzhou, China
| | - Chris Gehring
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Department of Chemistry, Biology & Biotechnology, University of Perugia, Perugia, Italy
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6
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Sagervanshi A, Naeem A, Geilfus CM, Kaiser H, Mühling KH. One-time abscisic acid priming induces long-term salinity resistance in Vicia faba: Changes in key transcripts, metabolites, and ionic relations. PHYSIOLOGIA PLANTARUM 2021; 172:146-161. [PMID: 33314239 DOI: 10.1111/ppl.13315] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/30/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Abscisic acid (ABA) priming is known to enhance plant growth and survival under salinity. However, the mechanisms mediating this long-term acclimatization to salt stress are still obscure. Specifically, the long-term transcriptional changes and their effects on ion relations were never investigated. This motivated us to study the long-term (8 days) effect of one-time 24 h root priming treatment with 10 μM ABA on transcription levels of relevant regulated key genes, osmotically relevant metabolites, and ionic concentrations in Vicia faba grown under 50 mM NaCl salinity. The novelty of this study is that we could demonstrate long-term effects of a one-time ABA application. ABA-priming was found to prevent the salt-induced decline in root and shoot dry matter, improved photosynthesis, and inhibited terminal wilting of plants. It substantially increased the mRNA level of AAPK and 14-3-3 ABA inducible kinases and ion transporters (PM H+ -ATPase, VFK1, KUP7, SOS1, and CLC1). These ABA-induced transcriptional changes went along with altered tissue ion patterns. Primed plants accumulated less Na+ and Cl- but more K+ , Ca2+ , Zn2+ , Fe2+ , Mn2+ , NO3 - , and SO4 2- . Priming changed the composition pattern of organic osmolytes under salinity, with glucose and fructose being dominant in unprimed, whereas sucrose was dominant in the primed plants. We conclude that one-time ABA priming mitigates salt stress in Vicia faba by persistently changing transcription patterns of key genes, stabilizing the ionic and osmotic balance, and improving photosynthesis and growth.
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Affiliation(s)
- Amit Sagervanshi
- Institute of Plant Nutrition and Soil Science, Kiel University, Kiel, Germany
| | - Asif Naeem
- Institute of Plant Nutrition and Soil Science, Kiel University, Kiel, Germany
| | - Christoph-Martin Geilfus
- Institute of Plant Nutrition and Soil Science, Kiel University, Kiel, Germany
- Division of Controlled Environment Horticulture, Faculty of Life Sciences, Albrecht Daniel Thaer-Institute of Agricultural and Horticultural Sciences, Humboldt-University of Berlin, Berlin, Germany
| | - Hartmut Kaiser
- Institute of Plant Nutrition and Soil Science, Kiel University, Kiel, Germany
| | - Karl H Mühling
- Institute of Plant Nutrition and Soil Science, Kiel University, Kiel, Germany
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7
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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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8
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Ma W, Yang G, Xiao Y, Zhao X, Wang J. ABA-dependent K + flux is one of the important features of the drought response that distinguishes Catalpa from two different habitats. PLANT SIGNALING & BEHAVIOR 2020; 15:1735755. [PMID: 32141360 PMCID: PMC7194386 DOI: 10.1080/15592324.2020.1735755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/22/2020] [Accepted: 02/24/2020] [Indexed: 06/01/2023]
Abstract
Abscisic acid (ABA)-induced stomatal closure can improve drought tolerance in higher plants. However, the relationship between ABA-related ion flux and improved drought resistance in the roots of woody plants is unclear. To investigate this relationship, we employed a noninvasive micro-test technique (NMT) to detect potassium (K+) flux in Catalpa fargesii and C. fargesii f. duclouxii after treatment with polyethylene glycol (PEG) and ABA. PEG treatment slightly increased the free proline content in both Catalpa species. However, simultaneous treatment with ABA and PEG resulted in a large increase in free proline content. Treatment with PEG led to a significant increase in K+ efflux, and both ABA and tetraethylammonium (TEA, a K+ channel inhibitor) blocked this efflux under short-term (1 d) and long-term (7 d) drought conditions. Furthermore, we detected SKOR (stelar K+ outward-rectifying channel) gene expression in roots, and the results showed that PEG significantly increased SKOR expression in C. fargesii f. duclouxii, but SKOR expression was inhibited by ABA in Catalpa fargesii. These findings indicate that ABA improves drought tolerance by inhibiting K+ efflux in Catalpa, but distinct ABA response patterns exist. Drought-tolerant species have better potassium retention are dependent on ABA, and can accumulate more proline than other species. SKOR is also ABA-dependent and sensitive to ABA, and K+ flux is a target of the ABA-mediated drought response.
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Affiliation(s)
- Wenjun Ma
- State Key Laboratory of Tree Genetics and Breeding, Beijing, PR China
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, PR China
- Key Laboratory of Tree Breeding and Cultivation, State Forestry and Grassland Administration, Beijing, PR China
- National Innovation Alliance of Catalapa Bungei, Beijing, PR China
| | - Guijuan Yang
- State Key Laboratory of Tree Genetics and Breeding, Beijing, PR China
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, PR China
- Key Laboratory of Tree Breeding and Cultivation, State Forestry and Grassland Administration, Beijing, PR China
- National Innovation Alliance of Catalapa Bungei, Beijing, PR China
| | - Yao Xiao
- State Key Laboratory of Tree Genetics and Breeding, Beijing, PR China
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, PR China
- Key Laboratory of Tree Breeding and Cultivation, State Forestry and Grassland Administration, Beijing, PR China
- National Innovation Alliance of Catalapa Bungei, Beijing, PR China
| | - Xiyang Zhao
- Northeast Forestry University, Harbin, PR China
| | - Junhui Wang
- State Key Laboratory of Tree Genetics and Breeding, Beijing, PR China
- Research Institute of Forestry, Chinese Academy of Forestry, Beijing, PR China
- Key Laboratory of Tree Breeding and Cultivation, State Forestry and Grassland Administration, Beijing, PR China
- National Innovation Alliance of Catalapa Bungei, Beijing, PR China
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9
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Colmenero-Flores JM, Franco-Navarro JD, Cubero-Font P, Peinado-Torrubia P, Rosales MA. Chloride as a Beneficial Macronutrient in Higher Plants: New Roles and Regulation. Int J Mol Sci 2019; 20:E4686. [PMID: 31546641 PMCID: PMC6801462 DOI: 10.3390/ijms20194686] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 09/02/2019] [Indexed: 12/24/2022] Open
Abstract
Chloride (Cl-) has traditionally been considered a micronutrient largely excluded by plants due to its ubiquity and abundance in nature, its antagonism with nitrate (NO3-), and its toxicity when accumulated at high concentrations. In recent years, there has been a paradigm shift in this regard since Cl- has gone from being considered a harmful ion, accidentally absorbed through NO3- transporters, to being considered a beneficial macronutrient whose transport is finely regulated by plants. As a beneficial macronutrient, Cl- determines increased fresh and dry biomass, greater leaf expansion, increased elongation of leaf and root cells, improved water relations, higher mesophyll diffusion to CO2, and better water- and nitrogen-use efficiency. While optimal growth of plants requires the synchronic supply of both Cl- and NO3- molecules, the NO3-/Cl- plant selectivity varies between species and varieties, and in the same plant it can be modified by environmental cues such as water deficit or salinity. Recently, new genes encoding transporters mediating Cl- influx (ZmNPF6.4 and ZmNPF6.6), Cl- efflux (AtSLAH3 and AtSLAH1), and Cl- compartmentalization (AtDTX33, AtDTX35, AtALMT4, and GsCLC2) have been identified and characterized. These transporters have proven to be highly relevant for nutrition, long-distance transport and compartmentalization of Cl-, as well as for cell turgor regulation and stress tolerance in plants.
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Affiliation(s)
- José M Colmenero-Flores
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Avda Reina Mercedes 10, 41012 Sevilla, Spain.
| | - Juan D Franco-Navarro
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Avda Reina Mercedes 10, 41012 Sevilla, Spain.
| | - Paloma Cubero-Font
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Avda Reina Mercedes 10, 41012 Sevilla, Spain.
- Biochimie et physiologie Moléculaire des Plantes (BPMP), Univ Montpellier, CNRS, INRA, SupAgro, 2 place P. Viala, 34060 Montpellier, France.
| | - Procopio Peinado-Torrubia
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Avda Reina Mercedes 10, 41012 Sevilla, Spain.
| | - Miguel A Rosales
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Avda Reina Mercedes 10, 41012 Sevilla, Spain.
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10
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Nieves-Cordones M, García-Sánchez F, Pérez-Pérez JG, Colmenero-Flores JM, Rubio F, Rosales MA. Coping With Water Shortage: An Update on the Role of K +, Cl -, and Water Membrane Transport Mechanisms on Drought Resistance. FRONTIERS IN PLANT SCIENCE 2019; 10:1619. [PMID: 31921262 PMCID: PMC6934057 DOI: 10.3389/fpls.2019.01619] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 11/18/2019] [Indexed: 05/21/2023]
Abstract
Drought is now recognized as the abiotic stress that causes most problems in agriculture, mainly due to the strong water demand from intensive culture and the effects of climate change, especially in arid/semi-arid areas. When plants suffer from water deficit (WD), a plethora of negative physiological alterations such as cell turgor loss, reduction of CO2 net assimilation rate, oxidative stress damage, and nutritional imbalances, among others, can lead to a decrease in the yield production and loss of commercial quality. Nutritional imbalances in plants grown under drought stress occur by decreasing water uptake and leaf transpiration, combined by alteration of nutrient uptake and long-distance transport processes. Plants try to counteract these effects by activating drought resistance mechanisms. Correct accumulation of salts and water constitutes an important portion of these mechanisms, in particular of those related to the cell osmotic adjustment and function of stomata. In recent years, molecular insights into the regulation of K+, Cl-, and water transport under drought have been gained. Therefore, this article brings an update on this topic. Moreover, agronomical practices that ameliorate drought symptoms of crops by improving nutrient homeostasis will also be presented.
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Affiliation(s)
- Manuel Nieves-Cordones
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura–CSIC, Murcia, Spain
- *Correspondence: Manuel Nieves-Cordones,
| | - Francisco García-Sánchez
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura–CSIC, Murcia, Spain
| | - Juan G. Pérez-Pérez
- Centro para el Desarrollo de la Agricultura Sostenible (CDAS), Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain
| | - Jose M. Colmenero-Flores
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Sevilla, Spain
| | - Francisco Rubio
- Departamento de Nutrición Vegetal, Centro de Edafología y Biología Aplicada del Segura–CSIC, Murcia, Spain
| | - Miguel A. Rosales
- Instituto de Recursos Naturales y Agrobiología, Spanish National Research Council (CSIC), Sevilla, Spain
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11
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Kobayashi NI, Sugita R, Nobori T, Tanoi K, Nakanishi TM. Tracer experiment using 42K + and 137Cs + revealed the different transport rates of potassium and caesium within rice roots. FUNCTIONAL PLANT BIOLOGY : FPB 2016; 43:151-160. [PMID: 32480449 DOI: 10.1071/fp15245] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/03/2015] [Indexed: 06/11/2023]
Abstract
The differences in the transport characteristics in planta between potassium (K+) and caesium (Cs+) was investigated using their radionuclides, 42K+ and 137Cs+. A tracer experiment using nutrient solutions supplemented with 42K and 137Cs revealed that the ratio of the root's K+ uptake rate to its Cs+ uptake rate was 7-11 times higher than the K+:Cs+ concentration ratio in the solution, and the number was varied depending on the K concentration in the solution and also on the growth condition. After entering through the root tissues, the 42K+:137Cs+ ratio in the shoots was 4.28 times higher than the value in the roots. However, the 42K+:137Cs+ ratio in each leaf did not differ significantly, indicating that the primary transport of K+ and Cs+ in the shoots are similarly regulated. In contrast, among the radionuclides stored in the roots over 4h, 30% of the 42K+ was exported from the roots over the following hour, whereas only 8% of 137Cs+ was exported. In addition, within the xylem, K+ was shown to travel slowly, whereas Cs+ passed quickly through the roots into the shoots. In conclusion, our study demonstrated very different transport patterns for the two ions in the root tissues.
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Affiliation(s)
- Natsuko I Kobayashi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Ryohei Sugita
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tatsuya Nobori
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Keitaro Tanoi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tomoko M Nakanishi
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Planes MD, Niñoles R, Rubio L, Bissoli G, Bueso E, García-Sánchez MJ, Alejandro S, Gonzalez-Guzmán M, Hedrich R, Rodriguez PL, Fernández JA, Serrano R. A mechanism of growth inhibition by abscisic acid in germinating seeds of Arabidopsis thaliana based on inhibition of plasma membrane H+-ATPase and decreased cytosolic pH, K+, and anions. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:813-25. [PMID: 25371509 PMCID: PMC4321545 DOI: 10.1093/jxb/eru442] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The stress hormone abscisic acid (ABA) induces expression of defence genes in many organs, modulates ion homeostasis and metabolism in guard cells, and inhibits germination and seedling growth. Concerning the latter effect, several mutants of Arabidopsis thaliana with improved capability for H(+) efflux (wat1-1D, overexpression of AKT1 and ost2-1D) are less sensitive to inhibition by ABA than the wild type. This suggested that ABA could inhibit H(+) efflux (H(+)-ATPase) and induce cytosolic acidification as a mechanism of growth inhibition. Measurements to test this hypothesis could not be done in germinating seeds and we used roots as the most convenient system. ABA inhibited the root plasma-membrane H(+)-ATPase measured in vitro (ATP hydrolysis by isolated vesicles) and in vivo (H(+) efflux from seedling roots). This inhibition involved the core ABA signalling elements: PYR/PYL/RCAR ABA receptors, ABA-inhibited protein phosphatases (HAB1), and ABA-activated protein kinases (SnRK2.2 and SnRK2.3). Electrophysiological measurements in root epidermal cells indicated that ABA, acting through the PYR/PYL/RCAR receptors, induced membrane hyperpolarization (due to K(+) efflux through the GORK channel) and cytosolic acidification. This acidification was not observed in the wat1-1D mutant. The mechanism of inhibition of the H(+)-ATPase by ABA and its effects on cytosolic pH and membrane potential in roots were different from those in guard cells. ABA did not affect the in vivo phosphorylation level of the known activating site (penultimate threonine) of H(+)-ATPase in roots, and SnRK2.2 phosphorylated in vitro the C-terminal regulatory domain of H(+)-ATPase while the guard-cell kinase SnRK2.6/OST1 did not.
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Affiliation(s)
- María D Planes
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Regina Niñoles
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Lourdes Rubio
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain
| | - Gaetano Bissoli
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Eduardo Bueso
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - María J García-Sánchez
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain
| | - Santiago Alejandro
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Miguel Gonzalez-Guzmán
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - Rainer Hedrich
- Institute for Plant Physiology and Biophysics, University Würzburg, Julis-von-Sachs Platz 2, D-97082, Würzburg, Germany
| | - Pedro L Rodriguez
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
| | - José A Fernández
- Departamento de Biología Vegetal, Facultad de Ciencias, Universidad de Málaga, Campus de Teatinos, 29071 Málaga, Spain
| | - Ramón Serrano
- Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain
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Shabala S, Pottosin I. Regulation of potassium transport in plants under hostile conditions: implications for abiotic and biotic stress tolerance. PHYSIOLOGIA PLANTARUM 2014; 151:257-79. [PMID: 24506225 DOI: 10.1111/ppl.12165] [Citation(s) in RCA: 274] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 12/15/2013] [Accepted: 01/13/2014] [Indexed: 05/18/2023]
Abstract
Intracellular potassium homeostasis is a prerequisite for the optimal operation of plant metabolic machinery and plant's overall performance. It is controlled by K(+) uptake, efflux and intracellular and long-distance relocation, mediated by a large number of K(+) -selective and non-selective channels and transporters located at both plasma and vacuolar membranes. All abiotic and biotic stresses result in a significant disturbance to intracellular potassium homeostasis. In this work, we discuss molecular mechanisms and messengers mediating potassium transport and homeostasis focusing on four major environmental stresses: salinity, drought, flooding and biotic factors. We argue that cytosolic K(+) content may be considered as one of the 'master switches' enabling plant transition from the normal metabolism to 'hibernated state' during first hours after the stress exposure and then to a recovery phase. We show that all these stresses trigger substantial disturbance to K(+) homeostasis and provoke a feedback control on K(+) channels and transporters expression and post-translational regulation of their activity, optimizing K(+) absorption and usage, and, at the extreme end, assisting the programmed cell death. We discuss specific modes of regulation of the activity of K(+) channels and transporters by membrane voltage, intracellular Ca(2+) , reactive oxygen species, polyamines, phytohormones and gasotransmitters, and link this regulation with plant-adaptive responses to hostile environments.
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Affiliation(s)
- Sergey Shabala
- School of Agricultural Science, University of Tasmania, Hobart, Tas, 7001, Australia
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Matsuda S, Nagasawa H, Yamashiro N, Yasuno N, Watanabe T, Kitazawa H, Takano S, Tokuji Y, Tani M, Takamure I, Kato K. Rice RCN1/OsABCG5 mutation alters accumulation of essential and nonessential minerals and causes a high Na/K ratio, resulting in a salt-sensitive phenotype. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 224:103-111. [PMID: 24908511 DOI: 10.1016/j.plantsci.2014.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Revised: 04/08/2014] [Accepted: 04/16/2014] [Indexed: 06/03/2023]
Abstract
Mineral balance and salt stress are major factors affecting plant growth and yield. Here, we characterized the effects of rice (Oryza sativa L.) reduced culm number1 (rcn1), encoding a G subfamily ABC transporter (OsABCG5) involved in accumulation of essential and nonessential minerals, the Na/K ratio, and salt tolerance. Reduced potassium and elevated sodium in field-grown plants were evident in rcn1 compared to original line 'Shiokari' and four independent rcn mutants, rcn2, rcn4, rcn5 and rcn6. A high Na/K ratio was evident in the shoots and roots of rcn1 under K starvation and salt stress in hydroponically cultured plants. Downregulation of SKC1/OsHKT1;5 in rcn1 shoots under salt stress demonstrated that normal function of RCN1/OsABCG5 is essential for upregulation of SKC1/OsHKT1;5 under salt stress. The accumulation of various minerals in shoots and roots was also altered in the rcn1 mutant compared to 'Shiokari' under control conditions, potassium starvation, and salt and d-sorbitol treatments. The rcn1 mutation resulted in a salt-sensitive phenotype. We concluded that RCN1/OsABCG5 is a salt tolerance factor that acts via Na/K homeostasis, at least partly by regulation of SKC1/OsHKT1;5 in shoots.
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Affiliation(s)
- Shuichi Matsuda
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Hidetaka Nagasawa
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Nobuhiro Yamashiro
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Naoko Yasuno
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Toshihiro Watanabe
- Graduate School of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Hideyuki Kitazawa
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Sho Takano
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Yoshihiko Tokuji
- Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Masayuki Tani
- Department of Food Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Itsuro Takamure
- Graduate School of Agriculture, Hokkaido University, Kita 9 Nishi 9, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Kiyoaki Kato
- Department of Agro-Environmental Science, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada, Obihiro, Hokkaido 080-8555, Japan.
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15
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Liu B, Feng D, Zhang B, Mu P, Zhang Y, He Y, Qi K, Wang J, Wang H. Musa paradisica RCI complements AtRCI and confers Na+ tolerance and K+ sensitivity in Arabidopsis. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 184:102-11. [PMID: 22284714 DOI: 10.1016/j.plantsci.2011.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Revised: 11/24/2011] [Accepted: 12/05/2011] [Indexed: 05/23/2023]
Abstract
The mechanisms involved in Na⁺/K⁺ uptake and extrusion are important in plant salt tolerance. In this study, we investigated the physiological role of a plasma membrane (PM)-localized protein, MpRCI, from plantain in transgenic Arabidopsis under NaCl and KCl stress and determined its effect on PM fluidity and H⁺-ATPase activity. The MpRCI gene exhibited high homology to the AtRCI2 gene family in Arabidopsis and was therefore able to complement for loss of the yeast AtRCI2-related PMP3 gene. Results of phenotypic espial and atomic emission spectrophotometer (AES) assays indicated that MpRCI overexpression in the AtRCI2A knockout mutant with reduced shoot Na⁺ and increased K⁺ exhibited increased Na⁺-tolerance and K⁺-sensitivity under NaCl or KCl treatments, respectively. Furthermore, comparisons of PM fluidity and H⁺-ATPase activity in shoots, with expression or absence of MpRCI/AtRCI2A expression under NaCl or KCl stress, showed MpRCI maintained PM fluidity and H⁺-ATPase activity under stress conditions. Results suggest that MpRCI plays an essential role in Na⁺/K⁺ flux in plant cells.
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Affiliation(s)
- Bing Liu
- Guangdong Key Laboratory of Plant Resources, State Key Laboratory for Biocontrol and Key Laboratory of Gene Engineering of Ministry of Education, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, PR China
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Bondada B, Shutthanandan J. Understanding Differential Responses of Grapevine (Vitis vinifera L.) Leaf and Fruit to Water Stress and Recovery Following Re-Watering. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/ajps.2012.39149] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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17
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Mahdid M, Kameli A, Ehlert C, Simonneau T. Rapid changes in leaf elongation, ABA and water status during the recovery phase following application of water stress in two durum wheat varieties differing in drought tolerance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2011; 49:1077-83. [PMID: 21868244 DOI: 10.1016/j.plaphy.2011.08.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 08/03/2011] [Indexed: 05/25/2023]
Abstract
This study aims to investigate the role of Abscisic acid (ABA) in water potential and turgor variations as well as growth recovery during the first phase of a rapid water stress induced by PEG6000. Two wheat varieties (Triticum durum L.), MBB (more tolerant) and OZ (less productive under drought), were grown in aerated nutrient solutions. Leaf elongation kinetics of the growing leaf 3 was estimated using LVDT. Water potential was measured using a pressure chamber; osmotic potential was estimated from expressed sap of elongation zone, turgor pressure of the same zone of leaf three was estimated directly by pressure probe. Growth rapidly ceased for a period of about one hour after the addition of PEG, gradual recovery was then observed for about 2 h. A significant difference was found in the % recovery of Leaf Elongation Rate (LER) and ABA between the two varieties, leading to better water status in MBB compared to OZ. The results of this study showed the possible role of ABA on growth resumption by the increase of relative water content and turgor via osmotic adjustment during the stress period in the leaves, which indicates the importance of OA in the resumption of LER even in the short term under conditions of water deficit. Full recovery of turgor but not of LER at the end stress period suggested the possible effect on cell wall extensibility (hardening) even at short term resulting from the rapid accumulation of ABA.
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Affiliation(s)
- Mohamed Mahdid
- Faculté des Sciences Biologiques, Université des Sciences et de la Technologie Houari Boumedienne, BP 32 Bab Ezzouar, Alger, Algeria.
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18
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Visscher AM, Paul AL, Kirst M, Guy CL, Schuerger AC, Ferl RJ. Growth performance and root transcriptome remodeling of Arabidopsis in response to Mars-like levels of magnesium sulfate. PLoS One 2010; 5:e12348. [PMID: 20808807 PMCID: PMC2925951 DOI: 10.1371/journal.pone.0012348] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Accepted: 07/12/2010] [Indexed: 12/30/2022] Open
Abstract
Background Martian regolith (unconsolidated surface material) is a potential medium for plant growth in bioregenerative life support systems during manned missions on Mars. However, hydrated magnesium sulfate mineral levels in the regolith of Mars can reach as high as 10 wt%, and would be expected to be highly inhibitory to plant growth. Methodology and Principal Findings Disabling ion transporters AtMRS2-10 and AtSULTR1;2, which are plasma membrane localized in peripheral root cells, is not an effective way to confer tolerance to magnesium sulfate soils. Arabidopsis mrs2-10 and sel1-10 knockout lines do not mitigate the growth inhibiting impacts of high MgSO4·7H2O concentrations observed with wildtype plants. A global approach was used to identify novel genes with potential to enhance tolerance to high MgSO4·7H2O (magnesium sulfate) stress. The early Arabidopsis root transcriptome response to elevated concentrations of magnesium sulfate was characterized in Col-0, and also between Col-0 and the mutant line cax1-1, which was confirmed to be relatively tolerant of high levels of MgSO4·7H2O in soil solution. Differentially expressed genes in Col-0 treated for 45 min. encode enzymes primarily involved in hormone metabolism, transcription factors, calcium-binding proteins, kinases, cell wall related proteins and membrane-based transporters. Over 200 genes encoding transporters were differentially expressed in Col-0 up to 180 min. of exposure, and one of the first down-regulated genes was CAX1. The importance of this early response in wildtype Arabidopsis is exemplified in the fact that only four transcripts were differentially expressed between Col-0 and cax1-1 at 180 min. after initiation of treatment. Conclusions/Significance The results provide a solid basis for the understanding of the metabolic response of plants to elevated magnesium sulfate soils; it is the first transcriptome analysis of plants in this environment. The results foster the development of Mars soil-compatible plants by showing that cax1 mutants exhibit partial tolerance to magnesium sulfate, and by elucidating a small subset (500 vs. >10,000) of candidate genes for mutation or metabolic engineering that will enhance tolerance to magnesium sulfate soils.
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Affiliation(s)
- Anne M. Visscher
- Horticultural Sciences Department, University of Florida, Gainesville, Florida, United States of America
| | - Anna-Lisa Paul
- Horticultural Sciences Department, University of Florida, Gainesville, Florida, United States of America
| | - Matias Kirst
- School of Forest Resources and Conservation, University of Florida, Gainesville, Florida, United States of America
| | - Charles L. Guy
- Environmental Horticulture Department, University of Florida, Gainesville, Florida, United States of America
| | - Andrew C. Schuerger
- Plant Pathology, University of Florida, Kennedy Space Center, Florida, United States of America
| | - Robert J. Ferl
- Horticultural Sciences Department, University of Florida, Gainesville, Florida, United States of America
- Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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Gyuricza V, Declerck S, Dupré de Boulois H. Arbuscular mycorrhizal fungi decrease radiocesium accumulation in Medicago truncatula. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2010; 101:591-6. [PMID: 20378216 DOI: 10.1016/j.jenvrad.2010.03.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Revised: 03/05/2010] [Accepted: 03/05/2010] [Indexed: 05/08/2023]
Abstract
The role of arbuscular mycorrhizal fungi (AMF) in plant radiocesium uptake and accumulation remains ambiguous. This is probably due to the presence of other soil microorganisms, the variability of soil characteristics and plant nutritional status or the availability of its chemical analogue, potassium (K). Here, we used an in vitro culture system to study the impact of increased concentration of K on radiocesium accumulation in non K-starved mycorrhizal and non-mycorrhizal Medicago truncatula plants. In the presence of AMF radiocesium uptake decreased regardless of the concentration of K, and its translocation from root to shoot was also significantly lower. Potassium also reduced the accumulation of radiocesium in plants but to a lesser extent than mycorrhization, and without any effect on translocation. These results suggest that AMF in combination with K can play a key role in reducing radiocesium uptake and its subsequent translocation to plant shoots, thereby representing good potential for improved phytomanagement of contaminated areas.
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Affiliation(s)
- Veronika Gyuricza
- Université catholique de Louvain, Earth and Life Institute (ELI), Laboratoire de Mycologie, 1348 Louvain-la-Neuve, Belgium
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20
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de Boulois HD, Joner EJ, Leyval C, Jakobsen I, Chen BD, Roos P, Thiry Y, Rufyikiri G, Delvaux B, Declerck S. Role and influence of mycorrhizal fungi on radiocesium accumulation by plants. JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 2008; 99:785-800. [PMID: 18055077 DOI: 10.1016/j.jenvrad.2007.10.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/18/2007] [Indexed: 05/25/2023]
Abstract
This review summarizes current knowledge on the contribution of mycorrhizal fungi to radiocesium immobilization and plant accumulation. These root symbionts develop extended hyphae in soils and readily contribute to the soil-to-plant transfer of some nutrients. Available data show that ecto-mycorrhizal (ECM) fungi can accumulate high concentration of radiocesium in their extraradical phase while radiocesium uptake and accumulation by arbuscular mycorrhizal (AM) fungi is limited. Yet, both ECM and AM fungi can transport radiocesium to their host plants, but this transport is low. In addition, mycorrhizal fungi could thus either store radiocesium in their intraradical phase or limit its root-to-shoot translocation. The review discusses the impact of soil characteristics, and fungal and plant transporters on radiocesium uptake and accumulation in plants, as well as the potential role of mycorrhizal fungi in phytoremediation strategies.
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Affiliation(s)
- H Dupré de Boulois
- Université catholique de Louvain, Unité de Microbiologie, Croix du Sud 3, 1348 Louvain-la-Neuve, Belgium
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21
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Köhler B. Step by step: deciphering ion transport in the root xylem parenchyma. PLANT SIGNALING & BEHAVIOR 2007; 2:303-305. [PMID: 19704629 PMCID: PMC2634158 DOI: 10.4161/psb.2.4.4068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 02/22/2007] [Indexed: 05/27/2023]
Abstract
Proton pumps produce electrical potential differences and differences in pH across the plasma membrane of cells which drive secondary ion transport through sym- and antiporters. We used the patch-clamp technique to characterize an H(+)-pump in the xylem parenchyma of barley roots. This cell type is of special interest with respect to xylem loading. Since it has been an ongoing debate whether xylem loading is a passive or an active process, the functional characterization of the H(+)-pump is of major interest in the context of previous work on ion channels through which passive salt efflux into the xylem vessels could occur. Cell-type specific features like its Ca(2+) dependence were determined, that are important to interpret its physiological role and eventually to model xylem loading. We conclude that the electrogenic pump in the xylem parenchyma does not participate directly in the transfer of KCl and KNO(3) to the xylem but, in combination with short-circuiting conductances, plays a crucial role in controlling xylem unloading and loading through modulation of the voltage difference across the plasma membrane. Here, our recent results on the H(+) pump are put in a larger context and open questions are highlighted.
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Zhang Y, Wang Z, Zhang L, Cao Y, Huang D, Tang K. Molecular cloning and stress-dependent regulation of potassium channel gene in Chinese cabbage (Brassica rapa ssp. Pekinensis). JOURNAL OF PLANT PHYSIOLOGY 2006; 163:968-78. [PMID: 16949960 DOI: 10.1016/j.jplph.2005.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 09/22/2005] [Indexed: 05/11/2023]
Abstract
Potassium channels are important for many physiological functions in plants, one of which is to regulate plant adaption to stress conditions. In this study, KCT2, the gene encoding a membrane-bound protein potassium channel (GenBank accession number: ), was isolated from Chinese cabbage (Brassica rapa ssp. Pekinensis) by RACE-PCR technique. Bioinformatics methods were performed for the gene structure and molecular similarity analysis. The KCT2 expression patterns under various stress conditions were studied by semi-quantitative RT-PCR. DNA gel blot was used to analyze genomic organization. The putative KCT2 was found to contain five membrane-spanning segments, a pore-forming domain (P-domain) between the last two transmembrane spans, a TxxTxGYGD motif in the P-domain and a putative cyclic nucleotide-binding-like domain within a long C-terminal region. KCT2 is closest to KAT2 in Arabidopsis. KCT2 could be a one-copy gene with different isoforms or belong to a small gene family with four or five members. KCT2 was expressed more strongly in leaves than in shoots and roots. KCT2 transcription products were up-regulated by a 4-h-incubation in abscisic acid (ABA) and various stress treatment including cold stress (4 degrees C) for 24 h, drought stress for 1h, and salt stress for 12 h. KCT2 transcription was not affected by anoxia stress for 8h and was down-regulated with cold stress for 48 h. KCT2 was cloned for the first time from the genus Brassica. Expression analysis indicated that in the early stage of plant adaption to stress conditions KCT2 is up-regulated, which results in a stimulation of potassium transport.
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Affiliation(s)
- Yidong Zhang
- School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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Fricke W, Akhiyarova G, Wei W, Alexandersson E, Miller A, Kjellbom PO, Richardson A, Wojciechowski T, Schreiber L, Veselov D, Kudoyarova G, Volkov V. The short-term growth response to salt of the developing barley leaf. JOURNAL OF EXPERIMENTAL BOTANY 2006; 57:1079-95. [PMID: 16513814 DOI: 10.1093/jxb/erj095] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recent results concerning the short-term growth response to salinity of the developing barley leaf are reviewed. Plants were grown hydroponically and the growth response of leaf 3 was studied between 10 min and 5 d following addition of 100 mM NaCl to the root medium. The aim of the experiments was to relate changes in variables that are likely to affect cell elongation to changes in leaf growth. Changes in hormone content (ABA, cytokinins), water and solute relationships (osmolality, turgor, water potential, solute concentrations), gene expression (water channel), cuticle deposition, membrane potential, and transpiration were followed, while leaf elongation velocity was monitored. Leaf elongation decreased close to zero within seconds following addition of NaCl. Between 20 and 30 min after exposure to salt, elongation velocity recovered rather abruptly, to about 46% of the pre-stress level, and remained at the reduced rate for the following 5 d, when it reached about 70% of the level in non-stressed plants. Biophysical and physiological analyses led to three major conclusions. (i) The immediate reduction and sudden recovery in elongation velocity is due to changes in the water potential gradient between leaf xylem and peripheral elongating cells. Changes in transpiration, ABA and cytokinin content, water channel expression, and plasma membrane potential are involved in this response. (ii) Significant solute accumulation, which aids growth recovery, is detectable from 1 h onwards; growing and non-growing leaf regions and mesophyll and epidermis differ in their solute response. (iii) Cuticular wax density is not affected by short-term exposure to salt; transpirational changes are due to stomatal control.
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Affiliation(s)
- Wieland Fricke
- Division of Biological Sciences, University of Paisley, Paisley PA1 2BE, UK.
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Roberts SK. Plasma membrane anion channels in higher plants and their putative functions in roots. THE NEW PHYTOLOGIST 2006; 169:647-66. [PMID: 16441747 DOI: 10.1111/j.1469-8137.2006.01639.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recent years have seen considerable progress in identifying anion channel activities in higher plant cells. This review outlines the functional properties of plasma membrane anion channels in plant cells and discusses their likely roles in root function. Plant anion channels can be grouped according to their voltage dependence and kinetics: (1) depolarization-activated anion channels which mediate either anion efflux (R and S types) or anion influx (outwardly rectifying type); (2) hyperpolarization-activated anion channels which mediate anion efflux, and (3) anion channels activated by light or membrane stretch. These types of anion channel are apparent in root cells where they may function in anion homeostasis, membrane stabilization, osmoregulation, boron tolerance and regulation of passive salt loading into the xylem vessels. In addition, roots possess anion channels exhibiting unique properties which are consistent with them having specialized functions in root physiology. Most notable are the organic anion selective channels, which are regulated by extracellular Al3+ or the phosphate status of the plant. Finally, although the molecular identities of plant anion channels remain elusive, the diverse electrophysiological properties of plant anion channels suggest that large and diverse multigene families probably encode these channels.
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Affiliation(s)
- Stephen K Roberts
- Lancaster Environment Centre, Biology Department, Lancaster University, Lancaster LA1 4YQ, UK.
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Gilliham M, Tester M. The regulation of anion loading to the maize root xylem. PLANT PHYSIOLOGY 2005; 137:819-28. [PMID: 15734917 PMCID: PMC1065381 DOI: 10.1104/pp.104.054056] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2004] [Revised: 12/09/2004] [Accepted: 12/22/2004] [Indexed: 05/20/2023]
Abstract
The regulation of anion loading to the shoot in maize (Zea mays) was investigated via an electrophysiological characterization of ion conductances in protoplasts isolated from the root stele. Two distinct anion conductances were identified. In protoplasts from well-watered plants, Z. mays xylem-parenchyma quickly-activating anion conductance (Zm-X-QUAC) was the most prevalent conductance and is likely to load the majority of NO(3)(-) and Cl(-) ions to the xylem in nonstressed conditions. Z. mays xylem-parenchyma inwardly-rectifying anion conductance was found at a lower frequency in protoplasts from well-watered plants than Zm-X-QUAC, was much smaller in magnitude in all observed conditions, and is unlikely to be such a major pathway for anion loading into the xylem. Activity of Z. mays xylem-parenchyma inwardly-rectifying anion conductance increased following a water stress prior to protoplast isolation, but the activity of the putative major anion-loading pathway, Zm-X-QUAC, decreased. Addition of abscisic acid (ABA) to protoplasts from well-watered plants also inhibited Zm-X-QUAC activity within minutes, as did a high free Ca(2+)concentration in the pipette. ABA was also seen to activate a Ca(2+)-permeable conductance (Z. mays xylem-parenchyma hyperpolarization activated cation conductance) in protoplasts from well-watered plants. It is postulated that the inhibition of anion loading into the xylem (an important response to a water stress) due to down-regulation of Zm-X-QUAC activity is mediated by an ABA-mediated rise in free cytosolic Ca(2+).
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Affiliation(s)
- Matthew Gilliham
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, United Kingdom
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Cellier F, Conéjéro G, Ricaud L, Luu DT, Lepetit M, Gosti F, Casse F. Characterization of AtCHX17, a member of the cation/H+ exchangers, CHX family, from Arabidopsis thaliana suggests a role in K+ homeostasis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2004; 39:834-46. [PMID: 15341627 DOI: 10.1111/j.1365-313x.2004.02177.x] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The Arabidopsis genome contains many sequences annotated as encoding H(+)-coupled cotransporters. Among those are the members of the cation:proton antiporter-2 (CPA2) family (or CHX family), predicted to encode Na(+),K(+)/H(+) antiporters. AtCHX17, a member of the CPA2 family, was selected for expression studies, and phenotypic analysis of knockout mutants was performed. AtCHX17 expression was only detected in roots. The gene was strongly induced by salt stress, potassium starvation, abscisic acid (ABA) and external acidic pH. Using the beta-glucuronidase reporter gene strategy and in situ RT-PCR experiments, we have found that AtCHX17 was expressed preferentially in epidermal and cortical cells of the mature root zones. Knockout mutants accumulated less K(+) in roots in response to salt stress and potassium starvation compared with the wild type. These data support the hypothesis that AtCHX17 is involved in K(+) acquisition and homeostasis.
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Affiliation(s)
- Françoise Cellier
- Biochimie et Physiologie Moléculaire des Plantes, UMR 5004 INRA/CNRS/ENSA-M/UM II, place Viala 34060 Montpellier Cedex 1, France
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Becker D, Hoth S, Ache P, Wenkel S, Roelfsema MRG, Meyerhoff O, Hartung W, Hedrich R. Regulation of the ABA-sensitive Arabidopsis potassium channel gene GORK in response to water stress. FEBS Lett 2003; 554:119-26. [PMID: 14596925 DOI: 10.1016/s0014-5793(03)01118-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The phytohormone abscisic acid (ABA) regulates many stress-related processes in plants. In this context ABA mediates the responsiveness of plants to environmental stresses such as drought, cold or salt. In response to water stress, ABA induces stomatal closure by activating Ca2+, K+ and anion channels in guard cells. To understand the signalling pathways that regulate these turgor control elements, we studied the transcriptional control of the K+ release channel gene GORK that is expressed in guard cells, roots and vascular tissue. GORK transcription was up-regulated upon onset of drought, salt stress and cold. The wilting hormone ABA that integrates responses to these stimuli induced GORK expression in seedlings in a time- and concentration-dependent manner and this induction was dependent on extracellular Ca2+. ABA-responsive expression of GORK was impaired in the ABA-insensitive mutants abi1-1 and abi2-1, indicating that these protein phosphatases are regulators of GORK expression. Application of ABA to suspension-cultured cells for 2 min followed by a 4 h chase was sufficient to manifest transcriptional activation of the K+ channel gene. As predicted for a process involved in drought adaptation, only 12-24 h after the release of the stress hormone, GORK mRNA slowly decreased. In contrast to other tissues, GORK expression as well as K+(out) channel activity in guard cells is ABA insensitive, allowing the plant to adjust stomatal movement and water status control separately.
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Affiliation(s)
- D Becker
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, University of Würzburg, Julius-von-Sachs-Platz 2, 97082 Würzburg, Germany.
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White PJ, Bowen HC, Demidchik V, Nichols C, Davies JM. Genes for calcium-permeable channels in the plasma membrane of plant root cells. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1564:299-309. [PMID: 12175911 DOI: 10.1016/s0005-2736(02)00509-6] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
In plant cells, Ca(2+) is required for both structural and biophysical roles. In addition, changes in cytosolic Ca(2+) concentration ([Ca(2+)](cyt)) orchestrate responses to developmental and environmental signals. In many instances, [Ca(2+)](cyt) is increased by Ca(2+) influx across the plasma membrane through ion channels. Although the electrophysiological and biochemical characteristics of Ca(2+)-permeable channels in the plasma membrane of plant cells are well known, genes encoding putative Ca(2+)-permeable channels have only recently been identified. By comparing the tissue expression patterns and electrophysiology of Ca(2+)-permeable channels in the plasma membrane of root cells with those of genes encoding candidate plasma membrane Ca(2+) channels, the genetic counterparts of specific Ca(2+)-permeable channels can be deduced. Sequence homologies and the physiology of transgenic antisense plants suggest that the Arabidopsis AtTPC1 gene encodes a depolarisation-activated Ca(2+) channel. Members of the annexin gene family are likely to encode hyperpolarisation-activated Ca(2+) channels, based on their corresponding occurrence in secretory or elongating root cells, their inhibition by La(3+) and nifedipine, and their increased activity as [Ca(2+)](cyt) is raised. Based on their electrophysiology and tissue expression patterns, AtSKOR encodes a depolarisation-activated outward-rectifying (Ca(2+)-permeable) K(+) channel (KORC) in stelar cells and AtGORK is likely to encode a KORC in the plasma membrane of other Arabidopsis root cells. Two candidate gene families, of cyclic-nucleotide gated channels (CNGC) and ionotropic glutamate receptor (GLR) homologues, are proposed as the genetic correlates of voltage-independent cation (VIC) channels.
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Affiliation(s)
- Philip J White
- Department of Plant Genetics and Biotechnology, Horticulture Research International, Wellesbourne, CV35 9EF, Warwick, UK.
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Fedoroff NV. Cross-talk in abscisic acid signaling. SCIENCE'S STKE : SIGNAL TRANSDUCTION KNOWLEDGE ENVIRONMENT 2002; 2002:re10. [PMID: 12107340 DOI: 10.1126/stke.2002.140.re10] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
"Cross-talk" in hormone signaling reflects an organism's ability to integrate different inputs and respond appropriately, a crucial function at the heart of signaling network operation. Abscisic acid (ABA) is a plant hormone involved in bud and seed dormancy, growth regulation, leaf senescence and abscission, stomatal opening, and a variety of plant stress responses. This review summarizes what is known about ABA signaling in the control of stomatal opening and seed dormancy and provides an overview of emerging knowledge about connections between ABA, ethylene, sugar, and auxin synthesis and signaling.
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Affiliation(s)
- Nina V Fedoroff
- Biotechnology Institute, Life Sciences Consortium, and Biology Department, Pennsylvania State University, University Park, PA 16802, USA.
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Köhler B, Wegner LH, Osipov V, Raschke K. Loading of nitrate into the xylem: apoplastic nitrate controls the voltage dependence of X-QUAC, the main anion conductance in xylem-parenchyma cells of barley roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2002; 30:133-142. [PMID: 12000450 DOI: 10.1046/j.1365-313x.2002.01269.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We report here that NO(3)(-) in the xylem exerts positive feedback on its loading into the xylem through a change in the voltage dependence of the Quickly Activating Anion Conductance, X-QUAC. Properties of this conductance were investigated on xylem-parenchyma protoplasts prepared from roots of Hordeum vulgare by applying the patch-clamp technique. Chord conductances were minimal around -40 mV and increased with plasma membrane depolarisation as well as with hyperpolarisation. Two gates with opposite voltage dependences were postulated. When 30 mM Cl- in the bath was replaced by NO(3)(-), a shift in the midpoint potential of the depolarisation-activated gate by about -60 mV from 43 to -16 mV occurred (K(m) = 3.4 mM). No such effect was seen when chloride was replaced by malate. Addition of 10 mM NO(3)(-)to the pipette solution and reduction of [Cl-] from 124 to 4 mM (to simulate cytoplasmic concentrations) did not interfere with the voltage dependence of X-QUAC activation, nor was it affected by changes in external [K+]. If only the NO(3)(-) effect on gating was considered, an increase of the NO(3)(-) concentration in the xylem sap to 5 mM would result in an enhancement of NO(3)(-) efflux by about 30%. Although the driving force for NO(3)(-) efflux would be reduced simultaneously, NO(3)(-) efflux into the xylem through X-QUAC would be maintained with high NO(3)(-) concentrations in the xylem sap; a situation which occurs for instance during the night.
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Affiliation(s)
- Barbara Köhler
- Universität Potsdam, Institut für Biochemie und Biologie, Lehrstuhl für Molekularbiologie, Karl-Liebknecht-Str. 25, Haus 20, 14476 Golm, Germany.
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Davies WJ, Wilkinson S, Loveys B. Stomatal control by chemical signalling and the exploitation of this mechanism to increase water use efficiency in agriculture. THE NEW PHYTOLOGIST 2002; 153:449-460. [PMID: 33863219 DOI: 10.1046/j.0028-646x.2001.00345.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Stomatal behaviour of plants in drying soil can be regulated by (long distance) chemical signals that provide the shoot with some measure of water availability. Although much emphasis has been placed on the plant hormone abscisic acid (ABA) as a central component of the signalling process, soil drying will modify the delivery to the shoot of a range of potential chemical signals. Here we consider the role that changes in the xylem sap pH might play in determining the access that ABA has to sites of action on the guard cells. We also show how redistribution of inorganic ions between different compartments in the leaf (localized chemical signalling) can provide sensitive control of stomata and water loss in response to potentially damaging changes in leaf temperature. Partial root zone drying is an irrigation technique that has been developed to allow exploitation of the plant's long distance signalling system. When the system is optimized, stomatal behaviour, shoot water status and leaf growth can be regulated such that water use efficiency (fruit yield/water used) can be significantly increased. We show how an understanding of the drought stress physiology of the whole plant can lead to substantial saving of irrigation water in agriculture.
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Affiliation(s)
- William J Davies
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK
| | - Sally Wilkinson
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ, UK
| | - Brian Loveys
- Horticulture Research Unit, CSIRO Plant Industry, PO Box 350, Glen Osmond, SA 5064, Australia
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Wilkinson S, Davies WJ. ABA-based chemical signalling: the co-ordination of responses to stress in plants. PLANT, CELL & ENVIRONMENT 2002; 25:195-210. [PMID: 11841663 DOI: 10.1046/j.0016-8025.2001.00824.x] [Citation(s) in RCA: 388] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
There is now strong evidence that the plant hormone abscisic acid (ABA) plays an important role in the regulation of stomatal behaviour and gas exchange of droughted plants. This regulation involves both long-distance transport and modulation of ABA concentration at the guard cells, as well as differential responses of the guard cells to a given dose of the hormone. We will describe how a plant can use the ABA signalling mechanism and other chemical signals to adjust the amount of water that it loses through its stomata in response to changes in both the rhizospheric and the aerial environment. The following components of the signalling process can play an important part in regulation: (a) ABA sequestration in the root; (b) ABA synthesis versus catabolism in the root; (c) the efficiency of ABA transfer across the root and into the xylem; (d) the exchange of ABA between the xylem lumen and the xylem parenchyma in the shoot; (e) the amount of ABA in the leaf symplastic reservoir and the efficiency of ABA sequestration and release from this compartment as regulated by factors such as root and leaf-sourced changes in pH; (f) cleavage of ABA from ABA conjugates in the leaf apoplast; (g) transfer of ABA from the leaf into the phloem; (h) the sensitivity of the guard cells to the [ABA] that finally reaches them; and lastly (i) the possible interaction between nitrate stress and the ABA signal.
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Affiliation(s)
- S. Wilkinson
- The Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster, LA1 4YQ, UK
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Tester M, Leigh RA. Partitioning of nutrient transport processes in roots. JOURNAL OF EXPERIMENTAL BOTANY 2001; 52:445-457. [PMID: 11326051 DOI: 10.1093/jexbot/52.suppl_1.445] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Roots have a range of cell types that each contribute to the acquisition of nutrients and their subsequent transfer to the xylem. The activities of these cells must be co-ordinated to ensure that delivery of nutrients to the shoot occurs at a rate that matches the demands of growth. The partitioning of transport processes between different cell types is thus essential for roots to function effectively. This partitioning is considered at the level of proteins, organelles and cells in relation to the accepted concepts of how nutrients are taken up by roots and delivered to the xylem. Using K+ as an example, the evidence underpinning current concepts is examined, gaps in understanding identified and the contribution of some new approaches assessed.
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Affiliation(s)
- M Tester
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK.
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