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Lemonnier P, Lawson T. Calvin cycle and guard cell metabolism impact stomatal function. Semin Cell Dev Biol 2024; 155:59-70. [PMID: 36894379 DOI: 10.1016/j.semcdb.2023.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/01/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023]
Abstract
Stomatal conductance (gs) determines CO2 uptake for photosynthesis (A) and water loss through transpiration, which is essential for evaporative cooling and maintenance of optimal leaf temperature as well as nutrient uptake. Stomata adjust their aperture to maintain an appropriate balance between CO2 uptake and water loss and are therefore critical to overall plant water status and productivity. Although there is considerable knowledge regarding guard cell (GC) osmoregulation (which drives differences in GC volume and therefore stomatal opening and closing), as well as the various signal transduction pathways that enable GCs to sense and respond to different environmental stimuli, little is known about the signals that coordinate mesophyll demands for CO2. Furthermore, chloroplasts are a key feature in GCs of many species, however, their role in stomatal function is unclear and a subject of debate. In this review we explore the current evidence regarding the role of these organelles in stomatal behaviour, including GC electron transport and Calvin-Benson-Bassham (CBB) cycle activity as well as their possible involvement correlating gs and A along with other potential mesophyll signals. We also examine the roles of other GC metabolic processes in stomatal function.
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Affiliation(s)
- P Lemonnier
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
| | - T Lawson
- School of Life Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK.
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2
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Li Y, Hui S, Yuan Y, Ye Y, Ma X, Zhang X, Zhang S, Zhang C, Chen Y. PhyB-dependent phosphorylation of mitogen-activated protein kinase cascade MKK2-MPK2 positively regulates red light-induced stomatal opening. PLANT, CELL & ENVIRONMENT 2023; 46:3323-3336. [PMID: 37493364 DOI: 10.1111/pce.14675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 05/20/2023] [Accepted: 07/02/2023] [Indexed: 07/27/2023]
Abstract
Red light induces stomatal opening by affecting photosynthesis, metabolism and triggering signal transductions in guard cells. Phytochrome B (phyB) plays a positive role in mediating red light-induced stomatal opening. However, phyB-mediated red light guard cell signalling is poorly understood. Here, we found that phyB-mediated sequential phosphorylation of mitogen-activated protein kinase kinase 2 (MAPKK2, MKK2) and MPK2 in guard cells is essential for red light-induced stomatal opening. Mutations in MKK2 and MPK2 led to reduced stomatal opening in response to white light, and these phenotypes could be observed under red light, not blue light. MKK2 interacted with MPK2 in vitro and in plants. MPK2 was directly phosphorylated by MKK2 in vitro. Red light triggered the phosphorylation of MKK2 in guard cells, and MKK2 phosphorylation was greatly reduced in phyB mutant. Simultaneously, red light-stimulated MPK2 phosphorylation in guard cells was inhibited in mkk2 mutant. Furthermore, mkk2 and mpk2 mutants exhibit significantly smaller stomatal apertures than that of wild type during the stomatal opening stage in the diurnal stomatal movements. Our results indicate that red light-promoted phyB-dependent phosphorylation of MKK2-MPK2 cascade in guard cells is essential for stomatal opening, which contributes to the fine-tuning of stomatal opening apertures under light.
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Affiliation(s)
- Yuzhen Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, Shijiazhuang, China
| | - Shimiao Hui
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Yaxin Yuan
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, Shijiazhuang, China
| | - Yahong Ye
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Xiaohan Ma
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, Shijiazhuang, China
| | - Xiaolu Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Shasha Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
| | - Chunguang Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, Shijiazhuang, China
| | - Yuling Chen
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Research Center of the Basic Discipline of Cell Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, China
- Hebei Collaboration Innovation Center for Cell Signaling and Environmental Adaptation, Hebei Key Laboratory of Molecular and Cellular Biology, Shijiazhuang, China
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3
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Lim SL, Flütsch S, Liu J, Distefano L, Santelia D, Lim BL. Arabidopsis guard cell chloroplasts import cytosolic ATP for starch turnover and stomatal opening. Nat Commun 2022; 13:652. [PMID: 35115512 PMCID: PMC8814037 DOI: 10.1038/s41467-022-28263-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 01/12/2022] [Indexed: 01/28/2023] Open
Abstract
Stomatal opening requires the provision of energy in the form of ATP for proton pumping across the guard cell (GC) plasma membrane and for associated metabolic rearrangements. The source of ATP for GCs is a matter of ongoing debate that is mainly fuelled by controversies around the ability of GC chloroplasts (GCCs) to perform photosynthesis. By imaging compartment-specific fluorescent ATP and NADPH sensor proteins in Arabidopsis, we show that GC photosynthesis is limited and mitochondria are the main source of ATP. Unlike mature mesophyll cell (MC) chloroplasts, which are impermeable to cytosolic ATP, GCCs import cytosolic ATP through NUCLEOTIDE TRANSPORTER (NTT) proteins. GCs from ntt mutants exhibit impaired abilities for starch biosynthesis and stomatal opening. Our work shows that GCs obtain ATP and carbohydrates via different routes from MCs, likely to compensate for the lower chlorophyll contents and limited photosynthesis of GCCs. Stomatal guard cells require ATP in order to fuel stomatal movements. Here the authors show that guard cell photosynthesis is limited, mitochondria are the main source of ATP and that guard cell chloroplasts import ATP via nucleotide transporters.
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Affiliation(s)
- Shey-Li Lim
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Sabrina Flütsch
- Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Jinhong Liu
- School of Biological Sciences, University of Hong Kong, Hong Kong, China
| | - Luca Distefano
- Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland
| | - Diana Santelia
- Institute of Integrative Biology, ETH Zürich, Zürich, Switzerland.
| | - Boon Leong Lim
- School of Biological Sciences, University of Hong Kong, Hong Kong, China. .,HKU Shenzhen Institute of Research and Innovation, Shenzhen, China. .,State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Hong Kong, China.
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Gradogna A, Scholz-Starke J, Pardo JM, Carpaneto A. Beyond the patch-clamp resolution: functional activity of nonelectrogenic vacuolar NHX proton/potassium antiporters and inhibition by phosphoinositides. THE NEW PHYTOLOGIST 2021; 229:3026-3036. [PMID: 33098586 DOI: 10.1111/nph.17021] [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: 07/29/2020] [Accepted: 10/12/2020] [Indexed: 05/12/2023]
Abstract
We combined the patch-clamp technique with ratiometric fluorescence imaging using the proton-responsive dye BCECF as a luminal probe. Upon application of a steep cytosol-directed potassium ion (K+ ) gradient in Arabidopsis mesophyll vacuoles, a strong and reversible acidification of the vacuolar lumen was detected, whereas no associated electrical currents were observed, in agreement with electroneutral cation/H+ exchange. Our data show that this acidification was generated by NHX antiport activity, because: it did not distinguish between K+ and sodium (Na+ ) ions; it was sensitive to the NHX inhibitor benzamil; and it was completely absent in vacuoles from nhx1 nhx2 double knockout plants. Our data further show that NHX activity could be reversed, was voltage-independent and specifically impaired by the low-abundance signaling lipid PI(3,5)P2 , which may regulate salt accumulation in plants by acting as a common messenger to coordinately shut down secondary active carriers responsible for cation and anion uptake inside the vacuole. Finally, we developed a theory based on thermodynamics, which supports the data obtained by our novel experimental approach. This work, therefore, represents a proof-of-principle that can be applied to the study of proton-dependent exchangers from plants and animals, which are barely detectable using conventional techniques.
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Affiliation(s)
- Antonella Gradogna
- Institute of Biophysics, National Research Council, Via De Marini 6, Genova, 16149, Italy
| | - Joachim Scholz-Starke
- Institute of Biophysics, National Research Council, Via De Marini 6, Genova, 16149, Italy
| | - José M Pardo
- Institute of Plant Biochemistry and Photosynthesis, CSIC-University of Seville, Seville, 41092, Spain
| | - Armando Carpaneto
- Institute of Biophysics, National Research Council, Via De Marini 6, Genova, 16149, Italy
- Department of Earth, Environment and Life Sciences (DISTAV), University of Genoa, Viale Benedetto XV 5, Genova, 16132, Italy
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Lawson T, Terashima I, Fujita T, Wang Y. Coordination Between Photosynthesis and Stomatal Behavior. THE LEAF: A PLATFORM FOR PERFORMING PHOTOSYNTHESIS 2018. [DOI: 10.1007/978-3-319-93594-2_6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Daloso DM, Medeiros DB, Dos Anjos L, Yoshida T, Araújo WL, Fernie AR. Metabolism within the specialized guard cells of plants. THE NEW PHYTOLOGIST 2017; 216:1018-1033. [PMID: 28984366 DOI: 10.1111/nph.14823] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 08/21/2017] [Indexed: 05/21/2023]
Abstract
Contents 1018 I. 1018 II. 1019 III. 1022 IV. 1025 V. 1026 VI. 1029 1030 References 1030 SUMMARY: Stomata are leaf epidermal structures consisting of two guard cells surrounding a pore. Changes in the aperture of this pore regulate plant water-use efficiency, defined as gain of C by photosynthesis per leaf water transpired. Stomatal aperture is actively regulated by reversible changes in guard cell osmolyte content. Despite the fact that guard cells can photosynthesize on their own, the accumulation of mesophyll-derived metabolites can seemingly act as signals which contribute to the regulation of stomatal movement. It has been shown that malate can act as a signalling molecule and a counter-ion of potassium, a well-established osmolyte that accumulates in the vacuole of guard cells during stomatal opening. By contrast, their efflux from guard cells is an important mechanism during stomatal closure. It has been hypothesized that the breakdown of starch, sucrose and lipids is an important mechanism during stomatal opening, which may be related to ATP production through glycolysis and mitochondrial metabolism, and/or accumulation of osmolytes such as sugars and malate. However, experimental evidence supporting this theory is lacking. Here we highlight the particularities of guard cell metabolism and discuss this in the context of the guard cells themselves and their interaction with the mesophyll cells.
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Affiliation(s)
- Danilo M Daloso
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, 60451-970, Brasil
| | - David B Medeiros
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brasil
| | - Letícia Dos Anjos
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza, Ceará, 60451-970, Brasil
| | - Takuya Yoshida
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
| | - Wagner L Araújo
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brasil
| | - Alisdair R Fernie
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, Potsdam-Golm, 14476, Germany
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7
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Suetsugu N, Takami T, Ebisu Y, Watanabe H, Iiboshi C, Doi M, Shimazaki KI. Guard cell chloroplasts are essential for blue light-dependent stomatal opening in Arabidopsis. PLoS One 2014; 9:e108374. [PMID: 25250952 PMCID: PMC4177113 DOI: 10.1371/journal.pone.0108374] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 08/20/2014] [Indexed: 01/13/2023] Open
Abstract
Blue light (BL) induces stomatal opening through the activation of H+-ATPases with subsequent ion accumulation in guard cells. In most plant species, red light (RL) enhances BL-dependent stomatal opening. This RL effect is attributable to the chloroplasts of guard cell, the only cells in the epidermis possessing this organelle. To clarify the role of chloroplasts in stomatal regulation, we investigated the effects of RL on BL-dependent stomatal opening in isolated epidermis, guard cell protoplasts, and intact leaves of Arabidopsis thaliana. In isolated epidermal tissues and intact leaves, weak BL superimposed on RL enhanced stomatal opening while BL alone was less effective. In guard cell protoplasts, RL enhanced BL-dependent H+-pumping and DCMU, a photosynthetic electron transport inhibitor, eliminated this effect. RL enhanced phosphorylation levels of the H+-ATPase in response to BL, but this RL effect was not suppressed by DCMU. Furthermore, DCMU inhibited both RL-induced and BL-dependent stomatal opening in intact leaves. The photosynthetic rate in leaves correlated positively with BL-dependent stomatal opening in the presence of DCMU. We conclude that guard cell chloroplasts provide ATP and/or reducing equivalents that fuel BL-dependent stomatal opening, and that they indirectly monitor photosynthetic CO2 fixation in mesophyll chloroplasts by absorbing PAR in the epidermis.
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Affiliation(s)
- Noriyuki Suetsugu
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
| | - Tsuneaki Takami
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
| | - Yuuta Ebisu
- Graduate School of System Life Sciences, Kyushu University, Fukuoka, Japan
| | - Harutaka Watanabe
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
| | - Chihoko Iiboshi
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
| | - Michio Doi
- Faculty of Art and Science, Kyushu University, Fukuoka, Japan
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8
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Wang Y, Noguchi K, Terashima I. Photosynthesis-dependent and -independent responses of stomata to blue, red and green monochromatic light: differences between the normally oriented and inverted leaves of sunflower. PLANT & CELL PHYSIOLOGY 2011; 52:479-89. [PMID: 21257606 DOI: 10.1093/pcp/pcr005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The effects of growth light environment on stomatal light responses were analyzed. We inverted leaves of sunflower (Helianthus annuus) for 2 weeks until their full expansion, and measured gas exchange properties of the adaxial and abaxial sides separately. The sensitivity to light assessed as the increase in stomatal conductance was generally higher in the abaxial stomata than in the adaxial stomata, and these differences could not be completely changed by the inversion treatment. We also treated the leaves with DCMU to inhibit photosynthesis and evaluated the photosynthesis-dependent and -independent components of stomatal light responses. The red light response of stomata in both normally oriented and inverted leaves relied only on the photosynthesis-dependent component. The blue light response involved both the photosynthesis-dependent and photosynthesis-independent components, and the relative contributions of the two components differed between the normally oriented and inverted leaves. A green light response was observed only in the abaxial stomata, which also involved the photosynthesis-dependent and photosynthesis-independent components, strongly suggesting the existence of a green light receptor in sunflower leaves. Moreover, acclimation of the abaxial stomata to strong direct light eliminated the photosynthesis-independent component in the green light response. The results showed that stomatal responses to monochromatic light change considerably in response to growth light environment, although some of these responses appear to be determined inherently.
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Affiliation(s)
- Yin Wang
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Tokyo, 113-0033 Japan.
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Shimazaki KI, Doi M, Assmann SM, Kinoshita T. Light regulation of stomatal movement. ANNUAL REVIEW OF PLANT BIOLOGY 2007; 58:219-47. [PMID: 17209798 DOI: 10.1146/annurev.arplant.57.032905.105434] [Citation(s) in RCA: 450] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Stomatal pores, each surrounded by a pair of guard cells, regulate CO2 uptake and water loss from leaves. Stomatal opening is driven by the accumulation of K+ salts and sugars in guard cells, which is mediated by electrogenic proton pumps in the plasma membrane and/or metabolic activity. Opening responses are achieved by coordination of light signaling, light-energy conversion, membrane ion transport, and metabolic activity in guard cells. In this review, we focus on recent progress in blue- and red-light-dependent stomatal opening. Because the blue-light response of stomata appears to be strongly affected by red light, we discuss underlying mechanisms in the interaction between blue-light signaling and guard cell chloroplasts.
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Affiliation(s)
- Ken-ichiro Shimazaki
- Department of Biology, Faculty of Science, Kyushu University, Ropponmatsu, Fukuoka 810-8560, Japan.
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10
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Wolf T, Guinot DR, Hedrich R, Dietrich P, Marten I. Nucleotides and Mg2+ ions differentially regulate K+ channels and non-selective cation channels present in cells forming the stomatal complex. PLANT & CELL PHYSIOLOGY 2005; 46:1682-9. [PMID: 16081526 DOI: 10.1093/pcp/pci184] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Voltage-dependent inward-rectifying (K(in)) and outward-rectifying (K(out)) K(+) channels are capable of mediating K(+) fluxes across the plasma membrane. Previous studies on guard cells or heterologously expressed K(+) channels provided evidence for the requirement of ATP to maintain K(+) channel activity. Here, the nucleotide and Mg(2+) dependencies of time-dependent K(in) and K(out) channels from maize subsidiary cells were examined, showing that MgATP as well as MgADP function as channel activators. In addition to K(out) channels, these studies revealed the presence of another outward-rectifying channel type (MgC) in the plasma membrane that however gates in a nucleotide-independent manner. MgC represents a new channel type distinguished from K(out) channels by fast activation kinetics, inhibition by elevated intracellular Mg(2+) concentration, permeability for K(+) as well as for Na(+) and insensitivity towards TEA(+). Similar observations made for guard cells from Zea mays and Vicia faba suggest a conserved regulation of channel-mediated K(+) and Na(+) transport in both cell types and species.
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Affiliation(s)
- Thomas Wolf
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Bioscience, University of Wuerzburg, Germany
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11
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Roelfsema MRG, Hedrich R. In the light of stomatal opening: new insights into 'the Watergate'. THE NEW PHYTOLOGIST 2005; 167:665-91. [PMID: 16101906 DOI: 10.1111/j.1469-8137.2005.01460.x] [Citation(s) in RCA: 300] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Stomata can be regarded as hydraulically driven valves in the leaf surface, which open to allow CO2 uptake and close to prevent excessive loss of water. Movement of these 'Watergates' is regulated by environmental conditions, such as light, CO2 and humidity. Guard cells can sense environmental conditions and function as motor cells within the stomatal complex. Stomatal movement results from the transport of K+ salts across the guard cell membranes. In this review, we discuss the biophysical principles and mechanisms of stomatal movement and relate these to ion transport at the plasma membrane and vacuolar membrane. Studies with isolated guard cells, combined with recordings on single guard cells in intact plants, revealed that light stimulates stomatal opening via blue light-specific and photosynthetic-active radiation-dependent pathways. In addition, guard cells sense changes in air humidity and the water status of distant tissues via the stress hormone abscisic acid (ABA). Guard cells thus provide an excellent system to study cross-talk, as multiple signaling pathways induce both short- and long-term responses in these sensory cells.
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Affiliation(s)
- M Rob G Roelfsema
- Molecular Plant Physiology and Biophysics, Julius-von-Sachs Institute for Biosciences, Biocenter, Würzburg University, Julius-von-Sachs-Platz 2, D-97082 Würzburg, Germany
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12
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Abstract
In this review we concentrate on guard cell metabolism and CO2 sensing. Although a matter of some controversy, it is generally accepted that the Calvin cycle plays a minor role in stomatal movements. Recent data emphasise the importance of guard cell starch degradation and of carbon import from the guard cell apoplast in promoting and maintaining stomatal opening. Chloroplast maltose and glucose transporters appear to be crucial to the export of carbon from both guard and mesophyll cells. The way guard cells sense CO2 remains an unresolved question. However, a better understanding of the cellular events downstream from CO2 sensing is emerging. We now recognise that there are common as well as unique steps in abscisic acid (ABA) and CO2 signalling pathways. For example, while ABA and CO2 both trigger increases in cytoplasmic free calcium, unlike ABA, CO2 does not promote a cytoplasmic pH change. Future advances in this area are likely to result from the increased use of techniques and resources, such as, reverse genetics, novel mutants, confocal imaging, and microarray analyses of the guard cell transcriptome.
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Affiliation(s)
- Alain Vavasseur
- CEA/Cadarache-DSV-DEVM, Laboratoire des Echanges Membranaires et Signalisation, UMR 6191 CNRS-CEA-Aix-Marseille II. 13108 St Paul Lez-Durance Cedex, France.
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13
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Bulychev AA, Wijngaard PWJ, Boer AH. Spatial Coordination of Chloroplast and Plasma Membrane Activities in Chara Cells and Its Disruption through Inactivation of 14-3-3 Proteins. BIOCHEMISTRY (MOSCOW) 2005. [DOI: 10.1007/s10541-005-0005-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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14
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Spatial coordination of chloroplast and plasma membrane activities in chara cells and its disruption through inactivation of 14-3-3 proteins. BIOCHEMISTRY (MOSCOW) 2005. [DOI: 10.1007/s10541-005-0051-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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van den Wijngaard PWJ, Sinnige MP, Roobeek I, Reumer A, Schoonheim PJ, Mol JNM, Wang M, De Boer AH. Abscisic acid and 14-3-3 proteins control K channel activity in barley embryonic root. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2005; 41:43-55. [PMID: 15610348 DOI: 10.1111/j.1365-313x.2004.02273.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Germination of seeds proceeds in general in two phases, an initial imbibition phase and a subsequent growth phase. In grasses like barley, the latter phase is evident as the emergence of the embryonic root (radicle). The hormone abscisic acid (ABA) inhibits germination because it prevents the embryo from entering and completing the growth phase. Genetic and physiological studies have identified many steps in the ABA signal transduction cascade, but how it prevents radicle elongation is still not clear. For elongation growth to proceed, uptake of osmotically active substances (mainly K(+)) is essential. Therefore, we have addressed the question of how the activity of K(+) permeable ion channels in the plasma membrane of radicle cells is regulated under conditions of slow (+ABA) and rapid germination (+fusicoccin). We found that ABA arrests radicle growth, inhibits net K(+) uptake and reduces the activity of K(+) (in) channels as measured with the patch-clamp technique. In contrast, fusicoccin (FC), a well-known stimulator of germination, stimulates radicle growth, net K(+) uptake and reduces the activity of K(+) (out) channels. Both types of channels are under the control of 14-3-3 proteins, known as integral components of signal transduction pathways and instrumental in FC action. Intriguingly, 14-3-3 affected both channels in an opposite fashion: whereas K(+) (in) channel activity was fully dependent upon 14-3-3 proteins, K(+) (out) channel activity was reduced by 14-3-3 proteins by 60%. Together with previous data showing that 14-3-3 proteins control the activity of the plasma membrane H(+)-ATPase, this makes 14-3-3 a prime candidate for molecular master regulator of the cellular osmo-pump. Regulation of the osmo-pump activity by ABA and FC is an important mechanism in controlling the growth of the embryonic root during seed germination.
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Affiliation(s)
- Paul W J van den Wijngaard
- Section of Molecular Plant Physiology and Biophysics, Department of Developmental Genetics, Faculty of Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam, The Netherlands
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16
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Davey MR, Anthony P, Power JB, Lowe KC. Plant protoplasts: status and biotechnological perspectives. Biotechnol Adv 2004; 23:131-71. [PMID: 15694124 DOI: 10.1016/j.biotechadv.2004.09.008] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2004] [Revised: 09/13/2004] [Accepted: 09/23/2004] [Indexed: 11/27/2022]
Abstract
Plant protoplasts ("naked" cells) provide a unique single cell system to underpin several aspects of modern biotechnology. Major advances in genomics, proteomics, and metabolomics have stimulated renewed interest in these osmotically fragile wall-less cells. Reliable procedures are available to isolate and culture protoplasts from a range of plants, including both monocotyledonous and dicotyledonous crops. Several parameters, particularly the source tissue, culture medium, and environmental factors, influence the ability of protoplasts and protoplast-derived cells to express their totipotency and to develop into fertile plants. Importantly, novel approaches to maximise the efficiency of protoplast-to-plant systems include techniques already well established for animal and microbial cells, such as electrostimulation and exposure of protoplasts to surfactants and respiratory gas carriers, especially perfluorochemicals and hemoglobin. However, despite at least four decades of concerted effort and technology transfer between laboratories worldwide, many species still remain recalcitrant in culture. Nevertheless, isolated protoplasts are unique to a range of experimental procedures. In the context of plant genetic manipulation, somatic hybridisation by protoplast fusion enables nuclear and cytoplasmic genomes to be combined, fully or partially, at the interspecific and intergeneric levels to circumvent naturally occurring sexual incompatibility barriers. Uptake of isolated DNA into protoplasts provides the basis for transient and stable nuclear transformation, and also organelle transformation to generate transplastomic plants. Isolated protoplasts are also exploited in numerous miscellaneous studies involving membrane function, cell structure, synthesis of pharmaceutical products, and toxicological assessments. This review focuses upon the most recent developments in protoplast-based technologies.
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Affiliation(s)
- Michael R Davey
- Plant Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK.
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Goh CH, Jung KH, Roberts SK, McAinsh MR, Hetherington AM, Park YI, Suh K, An G, Nam HG. Mitochondria provide the main source of cytosolic ATP for activation of outward-rectifying K+ channels in mesophyll protoplast of chlorophyll-deficient mutant rice (OsCHLH) seedlings. J Biol Chem 2003; 279:6874-82. [PMID: 14660680 DOI: 10.1074/jbc.m309071200] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The role of mitochondria in providing intracellular ATP that controls the activity of plasma membrane outward-rectifying K+ channels was evaluated. The OsCHLH rice mutant, which lacks chlorophyll in the thylakoids, was isolated by T-DNA gene trapping (Jung, K.-H., Hur, J., Ryu, C.-H., Choi, Y., Chung, Y.-Y., Miyao, A., Hirochika, H., and An, G. (2003) Plant Cell Physiol. 44, 463-472). The OsCHLH mutant is unable to fix CO2 and exhibits reduced growth. Wild type and mutant plants exhibit similar rates of respiratory O2 uptake in the dark, whereas the rate of photosynthetic O2 evolution by the mutant was negligible during illumination. During dark respiration the wild type and mutant exhibited similar levels of cytoplasmic ATP. In the mutant oligomycin treatment (an inhibitor of mitochondrial F1F0-ATPase) drastically reduced ATP production. The fact that this was reversed by the addition of glucose suggested that the mutant produced ATP exclusively from mitochondria but not from chloroplasts. In whole cell patch clamp experiments, the activity of outward-rectifying K+ channels of rice mesophyll cells showed ATP-dependent currents, which were 1.5-fold greater in wild type than in mutant cells. Channels in both wild type and mutant cells were deactivated by the removal of cytosolic ATP, whereas in the presence of ATP the channels remained active. We conclude that mesophyll cells in the OsCHLH rice mutant derive ATP from mitochondrial respiration, and that this is critical for the normal function of plasma membrane outward-rectifying K+ channels.
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Affiliation(s)
- Chang-Hyo Goh
- Bionanotechnology Center, Department of Life Science, Pohang University of Science and Technology, Kyungbuk, Korea.
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Stoelzle S, Kagawa T, Wada M, Hedrich R, Dietrich P. Blue light activates calcium-permeable channels in Arabidopsis mesophyll cells via the phototropin signaling pathway. Proc Natl Acad Sci U S A 2003; 100:1456-61. [PMID: 12540824 PMCID: PMC298794 DOI: 10.1073/pnas.0333408100] [Citation(s) in RCA: 129] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2002] [Indexed: 11/18/2022] Open
Abstract
Light is a central regulator of plant growth and development. Among the processes triggered by blue and UV-A light, phototropism, stomatal movement, and chloroplast orientation rely on the activation of blue-light receptors known as phototropins. So far, these photoreceptors constitute a class of light receptor kinases unique to the plant kingdom. In Arabidopsis thaliana, the two members phot1 and phot2 have been shown to display partially overlapping functions. Up to now little is known about the signaling cascade, which links these phototropins to the physiological responses downstream of blue-light perception. Here, we show that on illumination with blue light, but not red light, voltage-dependent and calcium-permeable channels activate in the plasma membrane of mesophyll cells. Blue-light stimulation in the presence of the photosynthetic electron transport inhibitor, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, indicates that blue-light receptors rather than photosynthesis control channel activity. Sensitivity toward the protein kinase inhibitor K252a further pointed to the possible involvement of light receptor kinases. In support of this hypothesis, in the photoreceptor mutant phot1-5, blue-light induction of calcium currents was dramatically reduced and was eliminated in the double mutant phot1-5 phot2-1. By contrast, in cry1-304 cry2-1, an Arabidopsis mutant lacking another class of plant blue-light receptors, the channel remained sensitive to blue light. We thus conclude that blue light triggers calcium fluxes via the phototropin-activated calcium-permeable channel.
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Affiliation(s)
- Sonja Stoelzle
- Department of Molecular Plant Physiology and Biophysics, Julius von Sachs Institute of Biosciences, Julius-von-Sachs-Platz 2, 97082 Würzburg, Germany
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