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Zhou H, Zhang M, Chang Y, Feng C, Long Y. A method for separating tonoplast from wheat. JOURNAL OF PLANT PHYSIOLOGY 2024; 299:154258. [PMID: 38761672 DOI: 10.1016/j.jplph.2024.154258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/20/2024]
Abstract
Vacuoles account for 90% of plant cell volume and play important roles in maintaining osmotic pressure, storing metabolites and lysosomes, compartmentalizing harmful ions, and storing and reusing minerals. These functions closely relay on the ion channels and transporters located on the tonoplast. The separation of intact vacuoles from plant cells is the key technology utilized in the study of tonoplast-located ion channels and transporters. However, the current vacuole separation methods are available for Arabidopsis and some other dicotyledons but are lacking for monocot crops. In this study, we established a new method for the vacuole separation from wheat mesophyll cells and investigated the transmembrane proton flux of tonoplasts with non-invasive micro-test technology (NMT). Moreover, our study provides a technology for the study of vacuole functions in monocot crops.
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Affiliation(s)
- Hui Zhou
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Mancang Zhang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Ying Chang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475001, China
| | - Cuizhu Feng
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475001, China.
| | - Yu Long
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475001, China.
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2
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Siadjeu C, Kadereit G. C 4-like Sesuvium sesuvioides (Aizoaceae) exhibits CAM in cotyledons and putative C 4-like + CAM metabolism in adult leaves as revealed by transcriptome analysis. BMC Genomics 2024; 25:688. [PMID: 39003461 PMCID: PMC11245778 DOI: 10.1186/s12864-024-10553-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 06/21/2024] [Indexed: 07/15/2024] Open
Abstract
BACKGROUND The co-occurrence of C4 and CAM photosynthesis in a single species seems to be unusual and rare. This is likely due to the difficulty in effectively co-regulating both pathways. Here, we conducted a comparative transcriptomic analysis of leaves and cotyledons of the C4-like species Sesuvium sesuvioides (Aizoaceae) using RNA-seq. RESULTS When compared to cotyledons, phosphoenolpyruvate carboxylase 4 (PEPC4) and some key C4 genes were found to be up-regulated in leaves. During the day, the expression of NADP-dependent malic enzyme (NADP-ME) was significantly higher in cotyledons than in leaves. The titratable acidity confirmed higher acidity in the morning than in the previous evening indicating the induction of weak CAM in cotyledons by environmental conditions. Comparison of the leaves of S. sesuvioides (C4-like) and S. portulacastrum (C3) revealed that PEPC1 was significantly higher in S. sesuvioides, while PEPC3 and PEPC4 were up-regulated in S. portulacastrum. Finally, potential key regulatory elements involved in the C4-like and CAM pathways were identified. CONCLUSIONS These findings provide a new species in which C4-like and CAM co-occur and raise the question if this phenomenon is indeed so rare or just hard to detect and probably more common in succulent C4 lineages.
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Affiliation(s)
- Christian Siadjeu
- Prinzessin Therese von Bayern Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilans-Universität München, Menzinger Str. 67, Munich, 80638, Germany.
| | - Gudrun Kadereit
- Prinzessin Therese von Bayern Lehrstuhl für Systematik, Biodiversität & Evolution der Pflanzen, Ludwig-Maximilans-Universität München, Menzinger Str. 67, Munich, 80638, Germany
- Botanischer Garten München-Nymphenburg Und Botanische Staatssammlung München, Staatliche Naturwissenschaftliche Sammlungen Bayerns, Menzinger Str. 65, Munich, 80638, Germany
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3
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Dondini L, Domenichini C, Dong Y, Gennari F, Bassi D, Foschi S, Lama M, Adami M, De Franceschi P, Cervellati C, Bergonzoni L, Alessandri S, Tartarini S. Quantitative Trait Loci Mapping and Identification of Candidate Genes Linked to Fruit Acidity in Apricot ( Prunus armeniaca L.). FRONTIERS IN PLANT SCIENCE 2022; 13:838370. [PMID: 35371156 PMCID: PMC8972129 DOI: 10.3389/fpls.2022.838370] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
Apricot breeding programs could be strongly improved by the availability of molecular markers linked to the main fruit quality traits. Fruit acidity is one of the key factors in consumer acceptance, but despite its importance, the molecular bases of this trait are still poorly understood. In order to increase the genetic knowledge on the fruit acidity, an F1 apricot population ('Lito' × 'BO81604311') has been phenotyped for titratable acidity and juice pH for the three following years. In addition, the contents of the main organic acids of the juice (malate, citrate, and quinate) were also evaluated. A Gaussian distribution was observed for most of the traits in this progeny, confirming their quantitative inheritance. An available simple sequence repeat (SSR)-based molecular map, implemented with new markers in specific genomic regions, was used to perform a quantitative trait loci (QTL) analysis. The molecular map was also anchored to the recently published apricot genome sequence of 'Stella.' Several major QTLs linked to fruit acidity-related traits have been identified both in the 'Lito' (no. 21) and 'BO81604311' (no. 13), distributed in five linkage groups (LG 4, 5, 6, 7, and 8). Some of these QTLs show good stability between years and their linked markers were used to identify candidate genes in specific QTLs genomic regions.
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Affiliation(s)
- Luca Dondini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Cecilia Domenichini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Yonghui Dong
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Fabio Gennari
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Daniele Bassi
- Department of Agricultural and Environmental Sciences (DISAA), University of Milan, Milan, Italy
| | | | | | - Marco Adami
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Paolo De Franceschi
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Claudia Cervellati
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Lorenzo Bergonzoni
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Sara Alessandri
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
| | - Stefano Tartarini
- Department of Agricultural and Food Sciences, Alma Mater Studiorum – University of Bologna, Bologna, Italy
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4
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Winter K, Smith JAC. CAM photosynthesis: the acid test. THE NEW PHYTOLOGIST 2022; 233:599-609. [PMID: 34637529 PMCID: PMC9298356 DOI: 10.1111/nph.17790] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 09/27/2021] [Indexed: 05/04/2023]
Abstract
There is currently considerable interest in the prospects for bioengineering crassulacean acid metabolism (CAM) photosynthesis - or key elements associated with it, such as increased water-use efficiency - into C3 plants. Resolving how CAM photosynthesis evolved from the ancestral C3 pathway could provide valuable insights into the targets for such bioengineering efforts. It has been proposed that the ability to accumulate organic acids at night may be common among C3 plants, and that the transition to CAM might simply require enhancement of pre-existing fluxes, without the need for changes in circadian or diurnal regulation. We show, in a survey encompassing 40 families of vascular plants, that nocturnal acidification is a feature entirely restricted to CAM species. Although many C3 species can synthesize malate during the light period, we argue that the switch to night-time malic acid accumulation requires a fundamental metabolic reprogramming that couples glycolytic breakdown of storage carbohydrate to the process of net dark CO2 fixation. This central element of the CAM pathway, even when expressed at a low level, represents a biochemical capability not seen in C3 plants, and so is better regarded as a discrete evolutionary innovation than as part of a metabolic continuum between C3 and CAM.
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Affiliation(s)
- Klaus Winter
- Smithsonian Tropical Research InstitutePO Box 0843‐03092BalboaAncónRepublic of Panama
| | - J. Andrew C. Smith
- Department of Plant SciencesUniversity of OxfordSouth Parks RoadOxfordOX1 3RBUK
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5
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Liao L, Zhang W, Zhang B, Fang T, Wang XF, Cai Y, Ogutu C, Gao L, Chen G, Nie X, Xu J, Zhang Q, Ren Y, Yu J, Wang C, Deng CH, Ma B, Zheng B, You CX, Hu DG, Espley R, Lin-Wang K, Yao JL, Allan AC, Khan A, Korban SS, Fei Z, Ming R, Hao YJ, Li L, Han Y. Unraveling a genetic roadmap for improved taste in the domesticated apple. MOLECULAR PLANT 2021; 14:1454-1471. [PMID: 34022440 DOI: 10.1016/j.molp.2021.05.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 04/13/2021] [Accepted: 05/17/2021] [Indexed: 05/26/2023]
Abstract
Although taste is an important aspect of fruit quality, an understanding of its genetic control remains elusive in apple and other fruit crops. In this study, we conducted genomic sequence analysis of 497 Malus accessions and revealed erosion of genetic diversity caused by apple breeding and possible independent domestication events of dessert and cider apples. Signatures of selection for fruit acidity and size, but not for fruit sugar content, were detected during the processes of both domestication and improvement. Furthermore, we found that single mutations in major genes affecting fruit taste, including Ma1, MdTDT, and MdSOT2, dramatically decrease malate, citrate, and sorbitol accumulation, respectively, and correspond to important domestication events. Interestingly, Ma1 was identified to have pleiotropic effects on both organic acid content and sugar:acid ratio, suggesting that it plays a vital role in determining fruit taste. Fruit taste is unlikely to have been negatively affected by linkage drag associated with selection for larger fruit that resulted from the pyramiding of multiple genes with minor effects on fruit size. Collectively, our study provides new insights into the genetic basis of fruit quality and its evolutionary roadmap during apple domestication, pinpointing several candidate genes for genetic manipulation of fruit taste in apple.
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Affiliation(s)
- Liao Liao
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China
| | - Weihan Zhang
- Agricultural Bioinformatics Key Laboratory of Hubei Province, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Bo Zhang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
| | - Ting Fang
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China
| | - Xiao-Fei Wang
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Yaming Cai
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; University of Chinese Academy of Sciences, 19A Yuquanlu, Beijing 100049, China
| | - Collins Ogutu
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Sino-African Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China
| | - Lei Gao
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China
| | - Gang Chen
- Agricultural Bioinformatics Key Laboratory of Hubei Province, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiaoqing Nie
- Agricultural Bioinformatics Key Laboratory of Hubei Province, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Jinsheng Xu
- Agricultural Bioinformatics Key Laboratory of Hubei Province, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Quanyan Zhang
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Yiran Ren
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Jianqiang Yu
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Chukun Wang
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Cecilia H Deng
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Baiquan Ma
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China
| | - Beibei Zheng
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China
| | - Chun-Xiang You
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Da-Gang Hu
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China
| | - Richard Espley
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Kui Lin-Wang
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Jia-Long Yao
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand
| | - Andrew C Allan
- The New Zealand Institute for Plant & Food Research Limited, Auckland, New Zealand; School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Awais Khan
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, Geneva, NY 14456, USA
| | - Schuyler S Korban
- Department of Natural Resources and Environmental Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Zhangjun Fei
- Boyce Thompson Institute, Cornell University, Ithaca, NY 14853, USA
| | - Ray Ming
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Yu-Jin Hao
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai-An 271018, China.
| | - Li Li
- Agricultural Bioinformatics Key Laboratory of Hubei Province, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China.
| | - Yuepeng Han
- CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture, Hubei Hongshan Laboratory, Wuhan Botanical Garden, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Wuhan 430074, China; Center of Economic Botany, Core Botanical Gardens, Chinese Academy of Sciences, Wuhan 430074, China; Sino-African Joint Research Center, Chinese Academy of Sciences, Wuhan 430074, China.
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6
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Abstract
Crassulacean acid metabolism (CAM) has evolved from a C3 ground state to increase water use efficiency of photosynthesis. During CAM evolution, selective pressures altered the abundance and expression patterns of C3 genes and their regulators to enable the trait. The circadian pattern of CO2 fixation and the stomatal opening pattern observed in CAM can be explained largely with a regulatory architecture already present in C3 plants. The metabolic CAM cycle relies on enzymes and transporters that exist in C3 plants and requires tight regulatory control to avoid futile cycles between carboxylation and decarboxylation. Ecological observations and modeling point to mesophyll conductance as a major factor during CAM evolution. The present state of knowledge enables suggestions for genes for a minimal CAM cycle for proof-of-concept engineering, assuming altered regulation of starch synthesis and degradation are not critical elements of CAM photosynthesis and sufficient malic acid export from the vacuole is possible.
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Affiliation(s)
- Katharina Schiller
- Computational Biology, Faculty of Biology, CeBiTec, Bielefeld University, 33615 Bielefeld, Germany; ,
| | - Andrea Bräutigam
- Computational Biology, Faculty of Biology, CeBiTec, Bielefeld University, 33615 Bielefeld, Germany; ,
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7
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Ceusters N, Borland AM, Ceusters J. How to resolve the enigma of diurnal malate remobilisation from the vacuole in plants with crassulacean acid metabolism? THE NEW PHYTOLOGIST 2021; 229:3116-3124. [PMID: 33159327 DOI: 10.1111/nph.17070] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 11/02/2020] [Indexed: 06/11/2023]
Abstract
Opening of stomata in plants with crassulacean acid metabolism (CAM) is mainly shifted to the night period when atmospheric CO2 is fixed by phosphoenolpyruvate carboxylase and stored as malic acid in the vacuole. As such, CAM plants ameliorate transpirational water losses and display substantially higher water-use efficiency compared with C3 and C4 plants. In the past decade significant technical advances have allowed an unprecedented exploration of genomes, transcriptomes, proteomes and metabolomes of CAM plants and efforts are ongoing to engineer the CAM pathway in C3 plants. Whilst research efforts have traditionally focused on nocturnal carboxylation, less information is known regarding the drivers behind diurnal malate remobilisation from the vacuole that liberates CO2 to be fixed by RuBisCo behind closed stomata. To shed more light on this process, we provide a stoichiometric analysis to identify potentially rate-limiting steps underpinning diurnal malate mobilisation and help direct future research efforts. Within this remit we address three key questions: Q1 Does light-dependent assimilation of CO2 via RuBisCo dictate the rate of malate mobilisation? Q2: Do the enzymes responsible for malate decarboxylation limit daytime mobilisation from the vacuole? Q3: Does malate efflux from the vacuole set the pace of decarboxylation?
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Affiliation(s)
- Nathalie Ceusters
- Faculty of Engineering Technology, Department of Biosystems, Division of Crop Biotechnics, Campus Geel, KU Leuven, Kleinhoefstraat 4, Geel, 2440, Belgium
| | - Anne M Borland
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne,, NE1 7RU, UK
| | - Johan Ceusters
- Faculty of Engineering Technology, Department of Biosystems, Division of Crop Biotechnics, Campus Geel, KU Leuven, Kleinhoefstraat 4, Geel, 2440, Belgium
- Centre for Environmental Sciences, Environmental Biology, UHasselt, Campus Diepenbeek, Agoralaan Building D, Diepenbeek, 3590, Belgium
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8
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Lefoulon C, Boxall SF, Hartwell J, Blatt MR. Crassulacean acid metabolism guard cell anion channel activity follows transcript abundance and is suppressed by apoplastic malate. THE NEW PHYTOLOGIST 2020; 227:1847-1857. [PMID: 32367511 DOI: 10.1111/nph.16640] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
Plants utilising crassulacean acid metabolism (CAM) concentrate CO2 around RuBisCO while reducing transpirational water loss associated with photosynthesis. Unlike stomata of C3 and C4 species, CAM stomata open at night for the mesophyll to fix CO2 into malate (Mal) and store it in the vacuole. CAM plants decarboxylate Mal in the light, generating high CO2 concentrations within the leaf behind closed stomata for refixation by RuBisCO. CO2 may contribute to stomatal closure but additional mechanisms, plausibly including Mal activation of anion channels, ensure closure in the light. In the CAM species Kalanchoë fedtschenkoi, we found that guard cell anion channel activity, recorded under voltage clamp, follows KfSLAC1 and KfALMT12 transcript abundance, declining to near zero by the end of the light period. Unexpectedly, however, we found that extracellular Mal inhibited the anion current of Kalanchoë guard cells, both in wild-type and RNAi mutants with impaired Mal metabolism. We conclude that the diurnal cycle of anion channel gene transcription, rather than the physiological signal of Mal release, is a key factor in the inverted CAM stomatal cycle.
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Affiliation(s)
- Cécile Lefoulon
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
| | - Susanna F Boxall
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool,, L69 7ZB, UK
| | - James Hartwell
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool,, L69 7ZB, UK
| | - Michael R Blatt
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Bower Building, Glasgow, G12 8QQ, UK
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9
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Ferrari RC, Bittencourt PP, Rodrigues MA, Moreno-Villena JJ, Alves FRR, Gastaldi VD, Boxall SF, Dever LV, Demarco D, Andrade SCS, Edwards EJ, Hartwell J, Freschi L. C 4 and crassulacean acid metabolism within a single leaf: deciphering key components behind a rare photosynthetic adaptation. THE NEW PHYTOLOGIST 2020; 225:1699-1714. [PMID: 31610019 DOI: 10.1111/nph.16265] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
Although biochemically related, C4 and crassulacean acid metabolism (CAM) systems are expected to be incompatible. However, Portulaca species, including P. oleracea, operate C4 and CAM within a single leaf, and the mechanisms behind this unique photosynthetic arrangement remain largely unknown. Here, we employed RNA-seq to identify candidate genes involved exclusively or shared by C4 or CAM, and provided an in-depth characterization of their transcript abundance patterns during the drought-induced photosynthetic transitions in P. oleracea. Data revealed fewer candidate CAM-specific genes than those recruited to function in C4 . The putative CAM-specific genes were predominantly involved in night-time primary carboxylation reactions and malate movement across the tonoplast. Analysis of gene transcript-abundance regulation and photosynthetic physiology indicated that C4 and CAM coexist within a single P. oleracea leaf under mild drought conditions. Developmental and environmental cues were shown to regulate CAM expression in stems, whereas the shift from C4 to C4 -CAM hybrid photosynthesis in leaves was strictly under environmental control. Moreover, efficient starch turnover was identified as part of the metabolic adjustments required for CAM operation in both organs. These findings provide insights into C4 /CAM connectivity and compatibility, contributing to a deeper understanding of alternative ways to engineer CAM into C4 crop species.
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Affiliation(s)
- Renata C Ferrari
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
| | - Priscila P Bittencourt
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
| | - Maria A Rodrigues
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
| | - Jose J Moreno-Villena
- Department of Ecology and Evolutionary Biology, Yale University, PO Box 208105, New Haven, CT, 06520, USA
| | - Frederico R R Alves
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
| | - Vinícius D Gastaldi
- Departamento e Instituto de Psiquiatria, Hospital das Clínicas (HCFMUSP), Faculdade de Medicina, Universidade de São Paulo, São Paulo, 05403-903, Brasil
| | - Susanna F Boxall
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Louisa V Dever
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Diego Demarco
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
| | - Sónia C S Andrade
- Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
| | - Erika J Edwards
- Department of Ecology and Evolutionary Biology, Yale University, PO Box 208105, New Haven, CT, 06520, USA
| | - James Hartwell
- Department of Functional and Comparative Genomics, Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Luciano Freschi
- Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, São Paulo, 05508-090, Brasil
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10
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Comparative Proteomic Analysis Reveals Key Proteins Linked to the Accumulation of Soluble Sugars and Organic Acids in the Mature Fruits of the Wild Malus Species. PLANTS 2019; 8:plants8110488. [PMID: 31717908 PMCID: PMC6918222 DOI: 10.3390/plants8110488] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/06/2019] [Accepted: 11/08/2019] [Indexed: 01/25/2023]
Abstract
Soluble sugars and organic acids are the main determinants of fruit organoleptic quality. To investigate the genes responsible for the soluble sugar and organic acid contents of apple fruits, a label-free proteomic analysis involving liquid chromatography (LC)-mass spectrometry (MS)/MS was conducted with the fruits of two Malus species, M. sargentii and M. niedzwetzkyana, which exhibit significant differences in soluble sugar and organic acid contents. A total of 13,036 unique peptides and 1,079 differentially-expressed proteins were identified. To verify the LC-MS/MS results, five candidate proteins were further analyzed by parallel reaction monitoring. The results were consistent with the LC-MS/MS data, which confirmed the reliability of the LC-MS/MS analysis. The functional annotation of the differentially-expressed proteins, based on the gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, revealed that they were mainly related to biological processes and cellular components. Additionally, the main enriched KEGG pathways were related to metabolic processes. Moreover, 31 proteins involved in soluble sugar metabolism, organic acid metabolism, and H+-transport were identified. The results of this study may be useful for the comprehensive characterization of the complex mechanism regulating apple fruit-soluble sugar and organic acid contents.
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11
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Ma B, Liao L, Fang T, Peng Q, Ogutu C, Zhou H, Ma F, Han Y. A Ma10 gene encoding P-type ATPase is involved in fruit organic acid accumulation in apple. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:674-686. [PMID: 30183123 PMCID: PMC6381788 DOI: 10.1111/pbi.13007] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 08/02/2018] [Accepted: 08/31/2018] [Indexed: 05/23/2023]
Abstract
Acidity is one of the main determinants of fruit organoleptic quality. Here, comparative transcriptome analysis was conducted between two cultivars that showed a significant difference in fruit acidity, but contained homozygous non-functional alleles at the major gene Ma1 locus controlling apple fruit acidity. A candidate gene for fruit acidity, designated M10, was identified. The M10 gene encodes a P-type proton pump, P3A -ATPase, which facilitates malate uptake into the vacuole. The Ma10 gene is significantly associated with fruit malate content, accounting for ~7.5% of the observed phenotypic variation in apple germplasm. Subcellular localization assay showed that the Ma10 is targeted to the tonoplast. Overexpression of the Ma10 gene can complement the defect in proton transport of the mutant YAK2 yeast strain and enhance the accumulation of malic acid in apple callus. Moreover, its ectopic expression in tomato induces a decrease in fruit pH. These results suggest that the Ma10 gene has the capacity for proton pumping and plays an important role in fruit vacuolar acidification in apple. Our study provides useful knowledge towards comprehensive understanding of the complex mechanism regulating apple fruit acidity.
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Affiliation(s)
- Baiquan Ma
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of AppleCollege of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
| | - Liao Liao
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- Sino‐African Joint Research CenterChinese Academy of SciencesWuhanChina
| | - Ting Fang
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- Graduate University of Chinese Academy of SciencesBeijingChina
| | - Qian Peng
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- Graduate University of Chinese Academy of SciencesBeijingChina
| | - Collins Ogutu
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- Graduate University of Chinese Academy of SciencesBeijingChina
| | - Hui Zhou
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- Sino‐African Joint Research CenterChinese Academy of SciencesWuhanChina
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of AppleCollege of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
| | - Yuepeng Han
- Key Laboratory of Plant Germplasm Enhancement and Specialty AgricultureWuhan Botanical Garden of the Chinese Academy of SciencesWuhanChina
- Sino‐African Joint Research CenterChinese Academy of SciencesWuhanChina
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12
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Schwachtje J, Whitcomb SJ, Firmino AAP, Zuther E, Hincha DK, Kopka J. Induced, Imprinted, and Primed Responses to Changing Environments: Does Metabolism Store and Process Information? FRONTIERS IN PLANT SCIENCE 2019; 10:106. [PMID: 30815006 PMCID: PMC6381073 DOI: 10.3389/fpls.2019.00106] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 01/23/2019] [Indexed: 05/21/2023]
Abstract
Metabolism is the system layer that determines growth by the rate of matter uptake and conversion into biomass. The scaffold of enzymatic reaction rates drives the metabolic network in a given physico-chemical environment. In response to the diverse environmental stresses, plants have evolved the capability of integrating macro- and micro-environmental events to be prepared, i.e., to be primed for upcoming environmental challenges. The hierarchical view on stress signaling, where metabolites are seen as final downstream products, has recently been complemented by findings that metabolites themselves function as stress signals. We present a systematic concept of metabolic responses that are induced by environmental stresses and persist in the plant system. Such metabolic imprints may prime metabolic responses of plants for subsequent environmental stresses. We describe response types with examples of biotic and abiotic environmental stresses and suggest that plants use metabolic imprints, the metabolic changes that last beyond recovery from stress events, and priming, the imprints that function to prepare for upcoming stresses, to integrate diverse environmental stress histories. As a consequence, even genetically identical plants should be studied and understood as phenotypically plastic organisms that continuously adjust their metabolic state in response to their individually experienced local environment. To explore the occurrence and to unravel functions of metabolic imprints, we encourage researchers to extend stress studies by including detailed metabolic and stress response monitoring into extended recovery phases.
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Affiliation(s)
- Jens Schwachtje
- Department of Molecular Physiology, Applied Metabolome Analysis, Max-Planck-Institute of Molecular Plant Physiology, Potsdam, Germany
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13
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Pereira PN, Gaspar M, Smith JAC, Mercier H. Ammonium intensifies CAM photosynthesis and counteracts drought effects by increasing malate transport and antioxidant capacity in Guzmania monostachia. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:1993-2003. [PMID: 29462338 PMCID: PMC6018993 DOI: 10.1093/jxb/ery054] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 02/07/2018] [Indexed: 05/25/2023]
Abstract
Guzmania monostachia (Bromeliaceae) is a tropical epiphyte capable of up-regulating crassulacean acid metabolism (CAM) in its photosynthetic tissues in response to changing nutrient and water availability. Previous studies have shown that under drought there is a gradient of increasing CAM expression from the basal (youngest) to the apical (oldest) portion of the leaves, and additionally that nitrogen deficiency can further increase CAM intensity in the leaf apex of this bromeliad. The present study investigated the inter-relationships between nitrogen source (nitrate and/or ammonium) and water deficit in regulating CAM expression in G. monostachia leaves. The highest CAM activity was observed under ammonium nutrition in combination with water deficit. This was associated with enhanced activity of the key enzyme phosphoenolpyruvate carboxylase, elevated rates of ATP- and PPi-dependent proton transport at the vacuolar membrane in the presence of malate, and increased transcript levels of the vacuolar malate channel-encoding gene, ALMT. Water deficit was consistently associated with higher levels of total soluble sugars, which were maximal under ammonium nutrition, as were the activities of several antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase). Thus, ammonium nutrition, whilst associated with the highest degree of CAM induction in G. monostachia, also mitigates the effects of water deficit by osmotic adjustment and can limit oxidative damage in the leaves of this bromeliad under conditions that may be typical of its epiphytic habitat.
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Affiliation(s)
- Paula Natália Pereira
- Department of Botany, Institute of Biosciences, University of São Paulo, CEP, São Paulo, SP, Brazil
| | - Marília Gaspar
- Department of Plant Physiology and Biochemistry, Institute of Botany, CEP, São Paulo, SP, Brazil
| | - J Andrew C Smith
- Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, UK
| | - Helenice Mercier
- Department of Botany, Institute of Biosciences, University of São Paulo, CEP, São Paulo, SP, Brazil
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14
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Frei B, Eisenach C, Martinoia E, Hussein S, Chen XZ, Arrivault S, Neuhaus HE. Purification and functional characterization of the vacuolar malate transporter tDT from Arabidopsis. J Biol Chem 2018; 293:4180-4190. [PMID: 29367340 DOI: 10.1074/jbc.ra117.000851] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 01/08/2018] [Indexed: 11/06/2022] Open
Abstract
The exact transport characteristics of the vacuolar dicarboxylate transporter tDT from Arabidopsis are elusive. To overcome this limitation, we combined a range of experimental approaches comprising generation/analysis of tDT overexpressors, 13CO2 feeding and quantification of 13C enrichment, functional characterization of tDT in proteoliposomes, and electrophysiological studies on vacuoles. tdt knockout plants showed decreased malate and increased citrate concentrations in leaves during the diurnal light-dark rhythm and after onset of drought, when compared with wildtypes. Interestingly, under the latter two conditions, tDT overexpressors exhibited malate and citrate levels opposite to tdt knockout plants. Highly purified tDT protein transports malate and citrate in a 1:1 antiport mode. The apparent affinity for malate decreased with decreasing pH, whereas citrate affinity increased. This observation indicates that tDT exhibits a preference for dianion substrates, which is supported by electrophysiological analysis on intact vacuoles. tDT also accepts fumarate and succinate as substrates, but not α-ketoglutarate, gluconate, sulfate, or phosphate. Taking tDT as an example, we demonstrated that it is possible to reconstitute a vacuolar metabolite transporter functionally in proteoliposomes. The displayed, so far unknown counterexchange properties of tDT now explain the frequently observed reciprocal concentration changes of malate and citrate in leaves from various plant species. tDT from Arabidopsis is the first member of the well-known and widely present SLC13 group of carrier proteins, exhibiting an antiport mode of transport.
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Affiliation(s)
- Benedikt Frei
- From Pflanzenphysiologie, Universität Kaiserslautern, Erwin Schrödinger-Strasse, D-67653 Kaiserslautern, Germany
| | - Cornelia Eisenach
- the Institut für Pflanzenbiologie, Universität Zürich, CH-8008 Zürich, Switzerland
| | - Enrico Martinoia
- the Institut für Pflanzenbiologie, Universität Zürich, CH-8008 Zürich, Switzerland
| | - Shaimaa Hussein
- the Faculty of Medicine and Dentistry, Department of Physiology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada, and
| | - Xing-Zhen Chen
- the Faculty of Medicine and Dentistry, Department of Physiology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada, and
| | - Stéphanie Arrivault
- the Max Planck-Institute of Molecular Plant Physiology, Wissenschaftspark Potsdam-Golm, Am Mühlenberg 1, D-14476 Potsdam, Germany
| | - H Ekkehard Neuhaus
- From Pflanzenphysiologie, Universität Kaiserslautern, Erwin Schrödinger-Strasse, D-67653 Kaiserslautern, Germany,
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15
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Wai CM, VanBuren R, Zhang J, Huang L, Miao W, Edger PP, Yim WC, Priest HD, Meyers BC, Mockler T, Smith JAC, Cushman JC, Ming R. Temporal and spatial transcriptomic and microRNA dynamics of CAM photosynthesis in pineapple. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:19-30. [PMID: 28670834 DOI: 10.1111/tpj.13630] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 06/20/2017] [Accepted: 06/23/2017] [Indexed: 05/21/2023]
Abstract
The altered carbon assimilation pathway of crassulacean acid metabolism (CAM) photosynthesis results in an up to 80% higher water-use efficiency than C3 photosynthesis in plants making it a potentially useful pathway for engineering crop plants with improved drought tolerance. Here we surveyed detailed temporal (diel time course) and spatial (across a leaf gradient) gene and microRNA (miRNA) expression patterns in the obligate CAM plant pineapple [Ananas comosus (L.) Merr.]. The high-resolution transcriptome atlas allowed us to distinguish between CAM-related and non-CAM gene copies. A differential gene co-expression network across green and white leaf diel datasets identified genes with circadian oscillation, CAM-related functions, and source-sink relations. Gene co-expression clusters containing CAM pathway genes are enriched with clock-associated cis-elements, suggesting circadian regulation of CAM. About 20% of pineapple microRNAs have diel expression patterns, with several that target key CAM-related genes. Expression and physiology data provide a model for CAM-specific carbohydrate flux and long-distance hexose transport. Together these resources provide a list of candidate genes for targeted engineering of CAM into C3 photosynthesis crop species.
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Affiliation(s)
- Ching M Wai
- FAFU and UIUC Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
| | - Robert VanBuren
- FAFU and UIUC Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
- Donald Danforth Plant Science Center, St. Louis, MO, USA
- Department of Horticulture, Michigan State University, East Lansing, MI, 48823, USA
| | - Jisen Zhang
- FAFU and UIUC Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Lixian Huang
- FAFU and UIUC Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Wenjing Miao
- FAFU and UIUC Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
| | - Patrick P Edger
- Department of Horticulture, Michigan State University, East Lansing, MI, 48823, USA
| | - Won C Yim
- Department of Biochemistry and Molecular Biology, MS330, University of Nevada, Reno, NV, 89557-0330, USA
| | - Henry D Priest
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Blake C Meyers
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Todd Mockler
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - J Andrew C Smith
- Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, MS330, University of Nevada, Reno, NV, 89557-0330, USA
| | - Ray Ming
- FAFU and UIUC Joint Center for Genomics and Biotechnology, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Agriculture and Forestry University, Fuzhou, 350002, Fujian, China
- Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
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16
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Pereira PN, Smith JAC, Mercier H. Nitrate enhancement of CAM activity in two Kalanchoë species is associated with increased vacuolar proton transport capacity. PHYSIOLOGIA PLANTARUM 2017; 160:361-372. [PMID: 28393374 DOI: 10.1111/ppl.12578] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/24/2017] [Accepted: 03/05/2017] [Indexed: 06/07/2023]
Abstract
Among species that perform CAM photosynthesis, members of the genus Kalanchoë have been studied frequently to investigate the effect of environmental factors on the magnitude of CAM activity. In particular, different nitrogen sources have been shown to influence the rate of nocturnal CO2 fixation and organic-acid accumulation in several species of Kalanchoë. However, there has been little investigation of the interrelationship between nitrogen source (nitrate versus ammonium), concentration and the activity of the vacuolar proton pumps responsible for driving nocturnal organic-acid accumulation in these species. In the present study with Kalanchoë laxiflora and Kalanchoë delagoensis cultivated on different nitrogen sources, both species were found to show highest total nocturnal organic-acid accumulation and highest rates of ATP- and PPi-dependent vacuolar proton transport on 2.5 mM nitrate, whereas plants cultivated on 5.0 mM ammonium showed the lowest values. In both species malate was the principal organic-acid accumulated during the night, but the second-most accumulated organic-acid was fumarate for K. laxiflora and citrate for K. delagoensis. Higher ATP- and PPi-dependent vacuolar proton transport rates and greater nocturnal acid accumulation were observed in K. delagoensis compared with K. laxiflora. These results show that the effect of nitrogen source on CAM activity in Kalanchoë species is reflected in corresponding differences in activity of the tonoplast proton pumps responsible for driving sequestration of these acids in the vacuole of CAM-performing cells.
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Affiliation(s)
- Paula Natália Pereira
- Department of Botany, Institute of Biosciences, University of São Paulo, São Paulo, 05508-090, Brazil
| | | | - Helenice Mercier
- Department of Botany, Institute of Biosciences, University of São Paulo, São Paulo, 05508-090, Brazil
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17
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Novikova EM, Vodeneev VA, Sukhov VS. Mathematical model of action potential in higher plants with account for the involvement of vacuole in the electrical signal generation. BIOCHEMISTRY MOSCOW SUPPLEMENT SERIES A-MEMBRANE AND CELL BIOLOGY 2017. [DOI: 10.1134/s1990747817010068] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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18
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Pereira PN, Smith JAC, Purgatto E, Mercier H. Proton and anion transport across the tonoplast vesicles in bromeliad species. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:646-653. [PMID: 32480595 DOI: 10.1071/fp16293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 03/10/2017] [Indexed: 06/11/2023]
Abstract
Crassulacean acid metabolism (CAM) is one of the key innovations in the Neotropical family Bromeliaceae that has enabled many of its species to occupy seasonally water-limited terrestrial environments or microclimatically arid epiphytic niches. However, the relationship between CAM activity and the transport processes responsible for vacuolar organic-acid accumulation at night has not been systematically explored in this family. In the present investigation, ATP- and PPi-dependent proton transport rates were studied in tonoplast membrane vesicles isolated from leaves of six CAM and one C3 species of bromeliads. A consistent feature of these species was the high activity of the tonoplast ATP-driven H+ pump, which, when averaged across the seven species tested, showed a higher specific activity than the tonoplast PPi-driven H+ pump. For all CAM species, the rate of ATP-dependent proton transport into the tonoplast vesicles was strongly influenced by the nature of the balancing organic-acid anion, which displayed the following order of effectiveness: fumarate>malate>citrate. Measurements of leaf organic-acid content in six CAM bromeliads at dusk and dawn showed that nocturnal accumulation of malate exceeded citrate by a factor of ~2.4-20.0-fold in five of six bromeliad species used in this study, demonstrating a close correlation between the CAM rhythm and the intrinsic properties of the vacuolar membrane across which these organic acids are transported.
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Affiliation(s)
- Paula Natália Pereira
- Department of Botany, Institute of Biosciences, Universidade de São Paulo, CEP 05508-090, São Paulo, SP, Brazil
| | | | - Eduardo Purgatto
- Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Sciences, Universidade de São Paulo,CEP 05422-970 São Paulo, SP, Brazil
| | - Helenice Mercier
- Department of Botany, Institute of Biosciences, Universidade de São Paulo, CEP 05508-090, São Paulo, SP, Brazil
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19
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Koselski M, Trebacz K, Dziubinska H. Vacuolar ion channels in the liverwort Marchantia polymorpha: influence of ion channel inhibitors. PLANTA 2017; 245:1049-1060. [PMID: 28197715 PMCID: PMC5391376 DOI: 10.1007/s00425-017-2661-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 02/07/2017] [Indexed: 05/04/2023]
Abstract
Potassium-permeable slow activating vacuolar channels (SV) and chloride-permeable channels in the vacuole of the liverwort Marchantia polymorpha were characterized in respect to calcium dependence, selectivity, and pharmacology. The patch-clamp method was used in the study of ion channel activity in the vacuoles from the liverwort Marchantia polymorpha. The whole-vacuole recordings allowed simultaneous observation of two types of currents-predominant slow activated currents recorded at positive voltages and fast activated currents recorded at negative voltages. Single-channel recordings carried out in the gradient of KCl indicated that slow activated currents were carried by potassium-permeable slowly activating vacuolar channels (SV) and fast activated currents-by chloride-permeable channels. Both types of the channels were dependent in an opposite way on calcium, since elimination of this ion from the cytoplasmic side caused inhibition of SV channels, but the open probability of chloride-permeable channels even increased. The dependence of the activity of both channels on different types of ion channel inhibitors was studied. SV channels exhibited different sensitivity to potassium channel inhibitors. These channels were insensitive to 3 mM Ba2+, but were blocked by 3 mM tetraethyl ammonium (TEA). Moreover, the activity of the channels was modified in a different way by calcium channel inhibitors. 200 µM Gd3+ was an effective blocker, but 50 µM ruthenium red evoked bursts of the channel activity resulting in an increase in the open probability. Different effectiveness of anion channel inhibitors was observed in chloride-permeable channels. After the application of 100 µM Zn2+, a decrease in the open probability was recorded but the channels were still active. 50 µM DIDS was more effective, as it completely blocked the channels.
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Affiliation(s)
- Mateusz Koselski
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland.
| | - Kazimierz Trebacz
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
| | - Halina Dziubinska
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland
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20
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Liu R, Li B, Qin G, Zhang Z, Tian S. Identification and Functional Characterization of a Tonoplast Dicarboxylate Transporter in Tomato ( Solanum lycopersicum). FRONTIERS IN PLANT SCIENCE 2017; 8:186. [PMID: 28261242 PMCID: PMC5311036 DOI: 10.3389/fpls.2017.00186] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 01/30/2017] [Indexed: 05/25/2023]
Abstract
Acidity plays an important role in flavor and overall organoleptic quality of fruit and is mainly due to the presence of organic acids. Understanding the molecular basis of organic acid metabolism is thus of primary importance for fruit quality improvement. Here, we cloned a putative tonoplast dicarboxylate transporter gene (SlTDT) from tomato, and submitted it to the NCBI database (GenBank accession number: KC733165). SlTDT protein contained 13 putative transmembrane domains in silico analysis. Confocal microscopic study using green fluorescent fusion proteins revealed that SlTDT was localized on tonoplast. The expression patterns of SlTDT in tomato were analyzed by RT-qPCR. The results indicated that SlTDT expressed in leaves, roots, flowers and fruits at different ripening stages, suggesting SlTDT may be associated with the development of different tissues. To further explore the function of SlTDT, we constructed both overexpression and RNAi vectors and obtained transgenic tomato plants by agrobacterium-mediated method. Gas chromatography-mass spectrometer (GC-MS) analysis showed that overexpression of SlTDT significantly increased malate content, and reduced citrate content in tomato fruit. By contrast, repression of SlTDT in tomato reduced malate content of and increased citrate content. These results indicated that SlTDT played an important role in remobilization of malate and citrate in fruit vacuoles.
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Affiliation(s)
- Ruiling Liu
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of SciencesBeijing, China
- College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
| | - Boqiang Li
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Guozheng Qin
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Zhanquan Zhang
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Shiping Tian
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of SciencesBeijing, China
- College of Life Sciences, University of Chinese Academy of SciencesBeijing, China
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21
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Vitali V, Sutka M, Amodeo G, Chara O, Ozu M. The Water to Solute Permeability Ratio Governs the Osmotic Volume Dynamics in Beetroot Vacuoles. FRONTIERS IN PLANT SCIENCE 2016; 7:1388. [PMID: 27695468 PMCID: PMC5024706 DOI: 10.3389/fpls.2016.01388] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 08/31/2016] [Indexed: 05/11/2023]
Abstract
Plant cell vacuoles occupy up to 90% of the cell volume and, beyond their physiological function, are constantly subjected to water and solute exchange. The osmotic flow and vacuole volume dynamics relies on the vacuole membrane -the tonoplast- and its capacity to regulate its permeability to both water and solutes. The osmotic permeability coefficient (Pf ) is the parameter that better characterizes the water transport when submitted to an osmotic gradient. Usually, Pf determinations are made in vitro from the initial rate of volume change, when a fast (almost instantaneous) osmolality change occurs. When aquaporins are present, it is accepted that initial volume changes are only due to water movements. However, in living cells osmotic changes are not necessarily abrupt but gradually imposed. Under these conditions, water flux might not be the only relevant driving force shaping the vacuole volume response. In this study, we quantitatively investigated volume dynamics of isolated Beta vulgaris root vacuoles under progressively applied osmotic gradients at different pH, a condition that modifies the tonoplast Pf . We followed the vacuole volume changes while simultaneously determining the external osmolality time-courses and analyzing these data with mathematical modeling. Our findings indicate that vacuole volume changes, under progressively applied osmotic gradients, would not depend on the membrane elastic properties, nor on the non-osmotic volume of the vacuole, but on water and solute fluxes across the tonoplast. We found that the volume of the vacuole at the steady state is determined by the ratio of water to solute permeabilites (Pf /Ps ), which in turn is ruled by pH. The dependence of the permeability ratio on pH can be interpreted in terms of the degree of aquaporin inhibition and the consequently solute transport modulation. This is relevant in many plant organs such as root, leaves, cotyledons, or stems that perform extensive rhythmic growth movements, which very likely involve considerable cell volume changes within seconds to hours.
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Affiliation(s)
- Victoria Vitali
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Instituto de Biodiversidad y Biología Experimental y Aplicada, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y TécnicasBuenos Aires, Argentina
| | - Moira Sutka
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Instituto de Biodiversidad y Biología Experimental y Aplicada, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y TécnicasBuenos Aires, Argentina
| | - Gabriela Amodeo
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Instituto de Biodiversidad y Biología Experimental y Aplicada, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y TécnicasBuenos Aires, Argentina
| | - Osvaldo Chara
- System Biology Group (SysBio), Institute of Physics of Liquids and Biological Systems (IFLYSIB) CONICET, University of La PlataLa Plata, Argentina
- Center for Information Services and High Performance Computing, Technische Universität DresdenDresden, Germany
| | - Marcelo Ozu
- Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Instituto de Biodiversidad y Biología Experimental y Aplicada, Universidad de Buenos Aires and Consejo Nacional de Investigaciones Científicas y TécnicasBuenos Aires, Argentina
- Departamento de Fisiología y Biofísica, Facultad de Medicina, Instituto de Fisiología y Biofísica (IFIBIO–Houssay), Universidad de Buenos Aires y Consejo Nacional de Investigaciones Científicas y TécnicasBuenos Aires, Argentina
- *Correspondence: Marcelo Ozu
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Liu J, Yang L, Luan M, Wang Y, Zhang C, Zhang B, Shi J, Zhao FG, Lan W, Luan S. A vacuolar phosphate transporter essential for phosphate homeostasis in Arabidopsis. Proc Natl Acad Sci U S A 2015; 112:E6571-8. [PMID: 26554016 PMCID: PMC4664319 DOI: 10.1073/pnas.1514598112] [Citation(s) in RCA: 126] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inorganic phosphate (Pi) is stored in the vacuole, allowing plants to adapt to variable Pi availability in the soil. The transporters that mediate Pi sequestration into vacuole remain unknown, however. Here we report the functional characterization of Vacuolar Phosphate Transporter 1 (VPT1), an SPX domain protein that transports Pi into the vacuole in Arabidopsis. The vpt1 mutant plants were stunted and consistently retained less Pi than wild type plants, especially when grown in medium containing high levels of Pi. In seedlings, VPT1 was expressed primarily in younger tissues under normal conditions, but was strongly induced by high-Pi conditions in older tissues, suggesting that VPT1 functions in Pi storage in young tissues and in detoxification of high Pi in older tissues. As a result, disruption of VPT1 rendered plants hypersensitive to both low-Pi and high-Pi conditions, reducing the adaptability of plants to changing Pi availability. Patch-clamp analysis of isolated vacuoles showed that the Pi influx current was severely reduced in vpt1 compared with wild type plants. When ectopically expressed in Nicotiana benthamiana mesophyll cells, VPT1 mediates vacuolar influx of anions, including Pi, SO4(2-), NO3(-), Cl(-), and malate with Pi as that preferred anion. The VPT1-mediated Pi current amplitude was dependent on cytosolic phosphate concentration. Single-channel analysis showed that the open probability of VPT1 was increased with the increase in transtonoplast potential. We conclude that VPT1 is a transporter responsible for vacuolar Pi storage and is essential for Pi adaptation in Arabidopsis.
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Affiliation(s)
- Jinlong Liu
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Lei Yang
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Mingda Luan
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Yuan Wang
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Chi Zhang
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Bin Zhang
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China
| | - Jisen Shi
- Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, Key Laboratory of Forest Genetics and Biotechnology, Nanjing Forestry University, Nanjing 210037, China
| | - Fu-Geng Zhao
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China;
| | - Wenzhi Lan
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China;
| | - Sheng Luan
- State Key Laboratory for Pharmaceutical Biotechnology, Nanjing University-Nanjing Forestry University Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing 210093, China; Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720
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Koselski M, Dziubinska H, Seta-Koselska A, Trebacz K. A nitrate-permeable ion channel in the tonoplast of the moss Physcomitrella patens. PLANTA 2015; 241:1207-19. [PMID: 25638644 PMCID: PMC4412613 DOI: 10.1007/s00425-015-2250-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 01/19/2015] [Indexed: 05/12/2023]
Abstract
In this work, for the first time the activity of nitrate-permeable channels in the tonoplast of the moss Physcomitrella patens was recorded. The channels allowed nitrate flow in one direction-from the cytoplasm to the vacuole. Selectivity of nitrate over chloride of the channels was proved. The activity of the channels was dependent on cytoplasmic calcium, magnesium, and pH. A patch-clamp study carried out on the vacuolar membrane of the moss Physcomitrella patens has revealed that inhibition of cation-selective channels leads to disclosure of channels permeable to NO3 (-). These channels were inwardly rectifying and allowed anions to flow from the cytoplasm to the vacuole. After a decrease in the cytoplasmic NO3 (-) concentration, the current density recorded in the whole-vacuole configuration and amplitude of the currents flowing through single channels were reduced. Application of the NO3 (-) gradient caused a shift in the reversal potential (Erev) towards ENO3-, indicating NO3 (-) permeability. Research of the selectivity of the channels to Cl(-) and NO3 (-) was also done; it indicated that Cl(-) is less permeable than NO3 (-) (PNO3/PCl = 3.08). Measurements with different concentrations of cytoplasmic Ca(2+) and Mg(2+) revealed that the channel was activated by different concentrations of these ions-100 µM Ca(2+) and 10 mM Mg(2+). Calcium dependence of the channels was also modulated by a redox agent-DTT (dithiothreitol), which added on the cytoplasmic side, caused a reduction in the threshold of channel activation with cytoplasmic Ca(2+). The NO3 (-) permeable channel was also pH dependent. A decrease in the cytoplasmic pH reduced the open probability of the channel; in turn, an increase in the vacuolar pH did not decrease ion channel activity but lowered its conductance.
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Affiliation(s)
- Mateusz Koselski
- Department of Biophysics, Institute of Biology and Biochemistry, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland,
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Knoblauch M, Froelich DR, Pickard WF, Peters WS. SEORious business: structural proteins in sieve tubes and their involvement in sieve element occlusion. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:1879-93. [PMID: 24591057 DOI: 10.1093/jxb/eru071] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The phloem provides a network of sieve tubes for long-distance translocation of photosynthates. For over a century, structural proteins in sieve tubes have presented a conundrum since they presumably increase the hydraulic resistance of the tubes while no potential function other than sieve tube or wound sealing in the case of injury has been suggested. Here we summarize and critically evaluate current speculations regarding the roles of these proteins. Our understanding suffers from the suggestive power of images; what looks like a sieve tube plug on micrographs may not actually impede translocation very much. Recent reports of an involvement of SEOR (sieve element occlusion-related) proteins, a class of P-proteins, in the sealing of injured sieve tubes are inconclusive; various lines of evidence suggest that, in neither intact nor injured plants, are SEORs determinative of translocation stoppage. Similarly, the popular notion that P-proteins serve in the defence against phloem sap-feeding insects is unsupported by empirical facts; it is conceivable that in functional sieve tubes, aphids actually could benefit from inducing a plug. The idea that rising cytosolic Ca(2+) generally triggers sieve tube blockage by P-proteins appears widely accepted, despite lacking experimental support. Even in forisomes, P-protein assemblages restricted to one single plant family and the only Ca(2+)-responsive P-proteins known, the available evidence does not unequivocally suggest that plug formation is the cause rather than a consequence of translocation stoppage. We conclude that the physiological roles of structural P-proteins remain elusive, and that in vivo studies of their dynamics in continuous sieve tube networks combined with flow velocity measurements will be required to (hopefully) resolve this scientific roadblock.
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Affiliation(s)
- Michael Knoblauch
- School of Biological Sciences, Washington State University, Pullman, WA 99164, USA
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25
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Wang Y, Chen ZH, Zhang B, Hills A, Blatt MR. PYR/PYL/RCAR abscisic acid receptors regulate K+ and Cl- channels through reactive oxygen species-mediated activation of Ca2+ channels at the plasma membrane of intact Arabidopsis guard cells. PLANT PHYSIOLOGY 2013; 163:566-77. [PMID: 23899646 PMCID: PMC3793038 DOI: 10.1104/pp.113.219758] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 07/25/2013] [Indexed: 05/17/2023]
Abstract
The discovery of the START family of abscisic acid (ABA) receptors places these proteins at the front of a protein kinase/phosphatase signal cascade that promotes stomatal closure. The connection of these receptors to Ca(2+) signals evoked by ABA has proven more difficult to resolve, although it has been implicated by studies of the pyrbactin-insensitive pyr1/pyl1/pyl2/pyl4 quadruple mutant. One difficulty is that flux through plasma membrane Ca(2+) channels and Ca(2+) release from endomembrane stores coordinately elevate cytosolic free Ca(2+) concentration ([Ca(2+)]i) in guard cells, and both processes are facilitated by ABA. Here, we describe a method for recording Ca(2+) channels at the plasma membrane of intact guard cells of Arabidopsis (Arabidopsis thaliana). We have used this method to resolve the loss of ABA-evoked Ca(2+) channel activity at the plasma membrane in the pyr1/pyl1/pyl2/pyl4 mutant and show the consequent suppression of [Ca(2+)]i increases in vivo. The basal activity of Ca(2+) channels was not affected in the mutant; raising the concentration of Ca(2+) outside was sufficient to promote Ca(2+) entry, to inactivate current carried by inward-rectifying K(+) channels and to activate current carried by the anion channels, both of which are sensitive to [Ca(2+)]i elevations. However, the ABA-dependent increase in reactive oxygen species (ROS) was impaired. Adding the ROS hydrogen peroxide was sufficient to activate the Ca(2+) channels and trigger stomatal closure in the mutant. These results offer direct evidence of PYR/PYL/RCAR receptor coupling to the activation by ABA of plasma membrane Ca(2+) channels through ROS, thus affecting [Ca(2+)]i and its regulation of stomatal closure.
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Affiliation(s)
| | | | - Ben Zhang
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow G12 8QQ, United Kingdom (Y.W., Z.-H.C., B.Z., A.H., M.R.B.); and
- School of Natural Sciences, University of Western Sydney, Hawkesbury Campus, Richmond, New South Wales 2753, Australia (Z.-H.C.)
| | - Adrian Hills
- Laboratory of Plant Physiology and Biophysics, University of Glasgow, Glasgow G12 8QQ, United Kingdom (Y.W., Z.-H.C., B.Z., A.H., M.R.B.); and
- School of Natural Sciences, University of Western Sydney, Hawkesbury Campus, Richmond, New South Wales 2753, Australia (Z.-H.C.)
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Etienne A, Génard M, Lobit P, Mbeguié-A-Mbéguié D, Bugaud C. What controls fleshy fruit acidity? A review of malate and citrate accumulation in fruit cells. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:1451-69. [PMID: 23408829 DOI: 10.1093/jxb/ert035] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Fleshy fruit acidity is an important component of fruit organoleptic quality and is mainly due to the presence of malic and citric acids, the main organic acids found in most ripe fruits. The accumulation of these two acids in fruit cells is the result of several interlinked processes that take place in different compartments of the cell and appear to be under the control of many factors. This review combines analyses of transcriptomic, metabolomic, and proteomic data, and fruit process-based simulation models of the accumulation of citric and malic acids, to further our understanding of the physiological mechanisms likely to control the accumulation of these two acids during fruit development. The effects of agro-environmental factors, such as the source:sink ratio, water supply, mineral nutrition, and temperature, on citric and malic acid accumulation in fruit cells have been reported in several agronomic studies. This review sheds light on the interactions between these factors and the metabolism and storage of organic acids in the cell.
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Affiliation(s)
- A Etienne
- Centre de Coopération International en Recherche Agronomique pour le Développement (CIRAD), UMR QUALISUD, Pôle de Recherche Agronomique de Martinique, BP 214, 97 285 Lamentin Cedex 2, France
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27
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Seidel T, Siek M, Marg B, Dietz KJ. Energization of vacuolar transport in plant cells and its significance under stress. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:57-131. [PMID: 23809435 DOI: 10.1016/b978-0-12-407696-9.00002-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plant vacuole is of prime importance in buffering environmental perturbations and in coping with abiotic stress caused by, for example, drought, salinity, cold, or UV. The large volume, the efficient integration in anterograde and retrograde vesicular trafficking, and the dynamic equipment with tonoplast transporters enable the vacuole to fulfill indispensible functions in cell biology, for example, transient and permanent storage, detoxification, recycling, pH and redox homeostasis, cell expansion, biotic defence, and cell death. This review first focuses on endomembrane dynamics and then summarizes the functions, assembly, and regulation of secretory and vacuolar proton pumps: (i) the vacuolar H(+)-ATPase (V-ATPase) which represents a multimeric complex of approximately 800 kDa, (ii) the vacuolar H(+)-pyrophosphatase, and (iii) the plasma membrane H(+)-ATPase. These primary proton pumps regulate the cytosolic pH and provide the driving force for secondary active transport. Carriers and ion channels modulate the proton motif force and catalyze uptake and vacuolar compartmentation of solutes and deposition of xenobiotics or secondary compounds such as flavonoids. ABC-type transporters directly energized by MgATP complement the transport portfolio that realizes the multiple functions in stress tolerance of plants.
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Affiliation(s)
- Thorsten Seidel
- Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
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28
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Ligaba A, Maron L, Shaff J, Kochian L, Piñeros M. Maize ZmALMT2 is a root anion transporter that mediates constitutive root malate efflux. PLANT, CELL & ENVIRONMENT 2012; 35:1185-200. [PMID: 22211473 DOI: 10.1111/j.1365-3040.2011.02479.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Root efflux of organic acid anions underlies a major mechanism of plant aluminium (Al) tolerance on acid soils. This efflux is mediated by transporters of the Al-activated malate transporter (ALMT) or the multi-drug and toxin extrusion (MATE) families. ZmALMT2 was previously suggested to be involved in Al tolerance based on joint association-linkage mapping for maize Al tolerance. In the current study, we functionally characterized ZmALMT2 by heterologously expressing it in Xenopus laevis oocytes and transgenic Arabidopsis. In oocytes, ZmALMT2 mediated an Al-independent electrogenic transport product of organic and inorganic anion efflux. Ectopic overexpression of ZmALMT2 in an Al-hypersensitive Arabidopsis KO/KD line lacking the Al tolerance genes, AtALMT1 and AtMATE, resulted in Al-independent constitutive root malate efflux which partially restored the Al tolerance phenotype. The lack of correlation between ZmALMT2 expression and Al tolerance (e.g., expression not localized to the root tip, not up-regulated by Al, and higher in sensitive versus tolerance maize lines) also led us to question ZmALMT2's role in Al tolerance. The functional properties of the ZmALMT2 transporter presented here, along with the gene expression data, suggest that ZmALMT2 is not involved in maize Al tolerance but, rather, may play a role in mineral nutrient acquisition and transport.
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Affiliation(s)
- Ayalew Ligaba
- Robert W. Holley Center for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, New York 14853, USA
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29
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Martinoia E, Meyer S, De Angeli A, Nagy R. Vacuolar transporters in their physiological context. ANNUAL REVIEW OF PLANT BIOLOGY 2012; 63:183-213. [PMID: 22404463 DOI: 10.1146/annurev-arplant-042811-105608] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Vacuoles in vegetative tissues allow the plant surface to expand by accumulating energetically cheap inorganic osmolytes, and thereby optimize the plant for absorption of sunlight and production of energy by photosynthesis. Some specialized cells, such as guard cells and pulvini motor cells, exhibit rapid volume changes. These changes require the rapid release and uptake of ions and water by the vacuole and are a prerequisite for plant survival. Furthermore, seed vacuoles are important storage units for the nutrients required for early plant development. All of these fundamental processes rely on numerous vacuolar transporters. During the past 15 years, the transporters implicated in most aspects of vacuolar function have been identified and characterized. Vacuolar transporters appear to be integrated into a regulatory network that controls plant metabolism. However, little is known about the mode of action of these fundamental processes, and deciphering the underlying mechanisms remains a challenge for the future.
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Affiliation(s)
- Enrico Martinoia
- Institute of Plant Biology, University of Zurich, Zurich, Switzerland.
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30
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Nath S, Elangovan R. New perspectives on photosynthetic phosphorylation in the light of a torsional mechanism of energy transduction and ATP synthesis. J Bioenerg Biomembr 2011; 43:601-10. [PMID: 22083127 DOI: 10.1007/s10863-011-9396-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 10/18/2011] [Indexed: 10/15/2022]
Abstract
New perspectives on photophosphorylation have been offered from the standpoint of the torsional mechanism of energy transduction and ATP synthesis. New experimental data on the involvement of malate anions in ATP synthesis in an acid-base malate bath procedure has been reported on spinach chloroplast thylakoids as the model system. The data cannot be reconciled with the chemiosmotic theory but has been shown to be naturally explained by the torsional mechanism. The path of malic acid in the acid and base stages of the experiment has been traced, offering further strong support to the new paradigm. Classical observations in the field have been re-interpreted in the light of these findings. A new concept of ion translocation, energy transduction and coupling at the overall physiological level in photophosphorylation has been presented and a large number of novel experimentally testable predictions have been made and shown to arise as logical consequences of the new perspectives.
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Affiliation(s)
- Sunil Nath
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi, 110016, India.
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31
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Meyer S, Scholz-Starke J, De Angeli A, Kovermann P, Burla B, Gambale F, Martinoia E. Malate transport by the vacuolar AtALMT6 channel in guard cells is subject to multiple regulation. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2011; 67:247-57. [PMID: 21443686 DOI: 10.1111/j.1365-313x.2011.04587.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Gas exchange in plants is controlled by guard cells, specialized cells acting as turgor pressure-driven valves. Malate is one of the major anions accumulated inside the vacuole during stomatal opening counteracting the positive charge of potassium. AtALMT6, a member of the aluminum-activated malate transporter family, is expressed in guard cells of leaves and stems as well as in flower organs of Arabidopsis thaliana. An AtALMT6-GFP fusion protein was targeted to the vacuolar membrane both in transient and stable expression systems. Patch-clamp experiments on vacuoles isolated from AtALMT6-GFP over-expressing Arabidopsis plants revealed large inward-rectifying malate currents only in the presence of micromolar cytosolic calcium concentrations. Further analyses showed that vacuolar pH and cytosolic malate regulate the threshold of activation of AtALMT6-mediated currents. The interplay of these two factors determines the AtALMT6 function as a malate influx or efflux channel depending on the tonoplast potential. Guard cell vacuoles isolated from Atalmt6 knock-out plants displayed reduced malate currents compared with wild-type vacuoles. This reduction, however, was not accompanied by phenotypic differences in the stomatal movements in knock-out plants, probably because of functional redundancy of malate transporters in guard cell vacuoles.
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Affiliation(s)
- Stefan Meyer
- Institute of Plant Biology, University of Zurich, Zurich, Switzerland
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Tavares B, Domingos P, Dias PN, Feijó JA, Bicho A. The essential role of anionic transport in plant cells: the pollen tube as a case study. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2273-2298. [PMID: 21511914 DOI: 10.1093/jxb/err036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Plasma membrane anion transporters play fundamental roles in plant cell biology, especially in stomatal closure and nutrition. Notwithstanding, a lot is still unknown about the specific function of these transporters, their specific localization, or molecular nature. Here the fundamental roles of anionic transport in plant cells are reviewed. Special attention will be paid to them in the control of pollen tube growth. Pollen tubes are extreme examples of cellular polarity as they grow exclusively in their apical extremity. Their unique cell biology has been extensively exploited for fundamental understanding of cellular growth and morphogenesis. Non-invasive methods have demonstrated that tube growth is governed by different ion fluxes, with different properties and distribution. Not much is known about the nature of the membrane transporters responsible for anionic transport and their regulation in the pollen tube. Recent data indicate the importance of chloride (Cl(-)) transfer across the plasma membrane for pollen germination and pollen tube growth. A general overview is presented of the well-known accumulated data in terms of biophysical and functional characterization, transcriptomics, and genomic description of pollen ionic transport, and the various controversies around the role of anionic fluxes during pollen tube germination, growth, and development. It is concluded that, like all other plant cells so far analysed, pollen tubes depend on anion fluxes for a number of fundamental homeostatic properties.
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Barbier-Brygoo H, De Angeli A, Filleur S, Frachisse JM, Gambale F, Thomine S, Wege S. Anion channels/transporters in plants: from molecular bases to regulatory networks. ANNUAL REVIEW OF PLANT BIOLOGY 2011; 62:25-51. [PMID: 21275645 DOI: 10.1146/annurev-arplant-042110-103741] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Anion channels/transporters are key to a wide spectrum of physiological functions in plants, such as osmoregulation, cell signaling, plant nutrition and compartmentalization of metabolites, and metal tolerance. The recent identification of gene families encoding some of these transport systems opened the way for gene expression studies, structure-function analyses of the corresponding proteins, and functional genomics approaches toward further understanding of their integrated roles in planta. This review, based on a few selected examples, illustrates that the members of a given gene family exhibit a diversity of substrate specificity, regulation, and intracellular localization, and are involved in a wide range of physiological functions. It also shows that post-translational modifications of transport proteins play a key role in the regulation of anion transport activity. Key questions arising from the increasing complexity of networks controlling anion transport in plant cells (the existence of redundancy, cross talk, and coordination between various pathways and compartments) are also addressed.
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Lüttge U. Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments. AOB PLANTS 2010; 2010:plq005. [PMID: 22476063 PMCID: PMC3000696 DOI: 10.1093/aobpla/plq005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 03/16/2010] [Accepted: 05/10/2010] [Indexed: 05/27/2023]
Abstract
BACKGROUND AND AIMS Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO(2), light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. CRASSULACEAN ACID METABOLISM The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. TROPICAL CAM HABITATS Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. MORPHOTYPICAL AND PHYSIOTYPICAL PLASTICITY OF CAM Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity).
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Affiliation(s)
- Ulrich Lüttge
- Institute of Botany, Technical University of Darmstadt, Schnittspahnstrasse 3-5, D-64287 Darmstadt, Germany
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35
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Vacuolar ion channels: Roles in plant nutrition and signalling. FEBS Lett 2010; 584:1982-8. [DOI: 10.1016/j.febslet.2010.02.050] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/17/2010] [Accepted: 02/18/2010] [Indexed: 11/19/2022]
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36
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Kim TH, Böhmer M, Hu H, Nishimura N, Schroeder JI. Guard cell signal transduction network: advances in understanding abscisic acid, CO2, and Ca2+ signaling. ANNUAL REVIEW OF PLANT BIOLOGY 2010; 61:561-91. [PMID: 20192751 PMCID: PMC3056615 DOI: 10.1146/annurev-arplant-042809-112226] [Citation(s) in RCA: 811] [Impact Index Per Article: 57.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Stomatal pores are formed by pairs of specialized epidermal guard cells and serve as major gateways for both CO(2) influx into plants from the atmosphere and transpirational water loss of plants. Because they regulate stomatal pore apertures via integration of both endogenous hormonal stimuli and environmental signals, guard cells have been highly developed as a model system to dissect the dynamics and mechanisms of plant-cell signaling. The stress hormone ABA and elevated levels of CO(2) activate complex signaling pathways in guard cells that are mediated by kinases/phosphatases, secondary messengers, and ion channel regulation. Recent research in guard cells has led to a new hypothesis for how plants achieve specificity in intracellular calcium signaling: CO(2) and ABA enhance (prime) the calcium sensitivity of downstream calcium-signaling mechanisms. Recent progress in identification of early stomatal signaling components are reviewed here, including ABA receptors and CO(2)-binding response proteins, as well as systems approaches that advance our understanding of guard cell-signaling mechanisms.
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Affiliation(s)
| | | | - Honghong Hu
- University of California, San Diego, Division of Biological Sciences, Section of Cell and Developmental Biology, La Jolla, California 92093-0116
| | - Noriyuki Nishimura
- University of California, San Diego, Division of Biological Sciences, Section of Cell and Developmental Biology, La Jolla, California 92093-0116
| | - Julian I. Schroeder
- University of California, San Diego, Division of Biological Sciences, Section of Cell and Developmental Biology, La Jolla, California 92093-0116
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Abstract
Due to the presence of plastids, eukaryotic photosynthetic cells represent the most highly compartmentalized eukaryotic cells. This high degree of compartmentation requires the transport of solutes across intracellular membrane systems by specific membrane transporters. In this review, we summarize the recent progress on functionally characterized intracellular plant membrane transporters and we link transporter functions to Arabidopsis gene identifiers and to the transporter classification system. In addition, we outline challenges in further elucidating the plant membrane permeome and we provide an outline of novel approaches for the functional characterization of membrane transporters.
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Affiliation(s)
- Nicole Linka
- Institute of Plant Biochemistry, Heinrich-Heine Universität Düsseldorf, Geb. 26.03.01, Universitätsstrasse 1, Düsseldorf, Germany
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Aliverdieva DA, Mamaev DV. Molecular characteristics of transporters of C4-dicarboxylates and mechanism of translocation. J EVOL BIOCHEM PHYS+ 2009. [DOI: 10.1134/s0022093009030016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Sweetman C, Deluc LG, Cramer GR, Ford CM, Soole KL. Regulation of malate metabolism in grape berry and other developing fruits. PHYTOCHEMISTRY 2009; 70:1329-44. [PMID: 19762054 DOI: 10.1016/j.phytochem.2009.08.006] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/07/2009] [Accepted: 08/07/2009] [Indexed: 05/21/2023]
Abstract
Organic acids are present in all plants, supporting numerous and varied facets of cellular metabolism. The type of organic acid found, and the levels to which they accumulate are extremely variable between species, developmental stages and tissue types. Acidity plays important roles in the organoleptic properties of plant tissues, where examples of both enhanced and reduced palatability can be ascribed to the presence of specific organic acids. In fruits, sourness is generally attributed to proton release from acids such as citric, malic, oxalic, quinic, succinic and tartaric, while the anion forms each contribute a distinct taste. Acidity imposes a strong influence on crop quality, and is an important factor in deciding the harvest date, particularly for fruits where acidity is important for further processing, as in wine grapes. In the grape, as for many other fruits, malate is one of the most prevalent acids, and is an important participant in numerous cellular functions. The accumulation of malate is thought to be due in large part to de novo synthesis in fruits such as the grape, through metabolism of assimilates translocated from leaf tissues, as well as photosynthetic activity within the fruit itself. During ripening, the processes through which malate is catabolised are of interest for advancing metabolic understanding, as well as for potential crop enhancement through agricultural or molecular practices. A body of literature describes research that has begun to unravel the regulatory mechanisms of enzymes involved in malate metabolism during fruit development, through exploration of protein and gene transcript levels. Datasets derived from a series of recent microarray experiments comparing transcript levels at several stages of grape berry development have been revisited, and are presented here with a focus on transcripts associated with malate metabolism. Developmental transcript patterns for enzymes potentially involved in grape malate metabolism have shown that some flux may occur through pathways that are less commonly regarded in ripening fruit, such as aerobic ethanol production. The data also suggest pyruvate as an important intermediate during malate catabolism in fruit. This review will combine an analysis of microarray data with information available on protein and enzyme activity patterns in grapes and other fruits, to explore pathways through which malate is conditionally metabolised, and how these may be controlled in response to developmental and climatic changes. Currently, an insufficient understanding of the complex pathways through which malate is degraded, and how these are regulated, prevents targeted genetic manipulation aimed at modifying fruit malate metabolism in response to environmental conditions.
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Affiliation(s)
- Crystal Sweetman
- School of Biological Sciences, Flinders University of South Australia, Bedford Park, SA 5042, Australia.
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40
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Borland AM, Griffiths H, Hartwell J, Smith JAC. Exploiting the potential of plants with crassulacean acid metabolism for bioenergy production on marginal lands. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:2879-96. [PMID: 19395392 DOI: 10.1093/jxb/erp118] [Citation(s) in RCA: 154] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Crassulacean acid metabolism (CAM) is a photosynthetic adaptation that facilitates the uptake of CO(2) at night and thereby optimizes the water-use efficiency of carbon assimilation in plants growing in arid habitats. A number of CAM species have been exploited agronomically in marginal habitats, displaying annual above-ground productivities comparable with those of the most water-use efficient C(3) or C(4) crops but with only 20% of the water required for cultivation. Such attributes highlight the potential of CAM plants for carbon sequestration and as feed stocks for bioenergy production on marginal and degraded lands. This review highlights the metabolic and morphological features of CAM that contribute towards high biomass production in water-limited environments. The temporal separation of carboxylation processes that underpins CAM provides flexibility for modulating carbon gain over the day and night, and poses fundamental questions in terms of circadian control of metabolism, growth, and productivity. The advantages conferred by a high water-storage capacitance, which translate into an ability to buffer fluctuations in environmental water availability, must be traded against diffusive (stomatal plus internal) constraints imposed by succulent CAM tissues on CO(2) supply to the cellular sites of carbon assimilation. The practicalities for maximizing CAM biomass and carbon sequestration need to be informed by underlying molecular, physiological, and ecological processes. Recent progress in developing genetic models for CAM are outlined and discussed in light of the need to achieve a systems-level understanding that spans the molecular controls over the pathway through to the agronomic performance of CAM and provision of ecosystem services on marginal lands.
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Affiliation(s)
- Anne M Borland
- Institute for Research on the Environment and Sustainability, Newcastle University, Newcastle Upon Tyne NE1 7RU, UK.
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41
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De Angeli A, Monachello D, Ephritikhine G, Frachisse JM, Thomine S, Gambale F, Barbier-Brygoo H. Review. CLC-mediated anion transport in plant cells. Philos Trans R Soc Lond B Biol Sci 2009; 364:195-201. [PMID: 18957376 DOI: 10.1098/rstb.2008.0128] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Plants need nitrate for growth and store the major part of it in the central vacuole of cells from root and shoot tissues. Based on few studies on the two model plants Arabidopsis thaliana and rice, members of the large ChLoride Channel (CLC) family have been proposed to encode anion channels/transporters involved in nitrate homeostasis. Proteins from the Arabidopsis CLC family (AtClC, comprising seven members) are present in various membrane compartments including the vacuolar membrane (AtClCa), Golgi vesicles (AtClCd and AtClCf) or chloroplast membranes (AtClCe). Through a combination of electrophysiological and genetic approaches, AtClCa was shown to function as a 2NO3-/1H+ exchanger that is able to accumulate specifically nitrate into the vacuole, in agreement with the main phenotypic trait of knockout mutant plants that accumulate 50 per cent less nitrate than their wild-type counterparts. The set-up of a functional complementation assay relying on transient expression of AtClCa cDNA in the mutant background opens the way for studies on structure-function relationships of the AtClCa nitrate transporter. Such studies will reveal whether important structural determinants identified in bacterial or mammalian CLCs are also crucial for AtClCa transport activity and regulation.
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Affiliation(s)
- Alexis De Angeli
- Institut des Sciences du Végétal, UPR2355 CNRS, Gif sur Yvette Cedex, France Istituto di Biofisica, CNR, Genova, Italy
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42
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Abstract
Distinct potassium, anion, and calcium channels in the plasma membrane and vacuolar membrane of plant cells have been identified and characterized by patch clamping. Primarily owing to advances in Arabidopsis genetics and genomics, and yeast functional complementation, many of the corresponding genes have been identified. Recent advances in our understanding of ion channel genes that mediate signal transduction and ion transport are discussed here. Some plant ion channels, for example, ALMT and SLAC anion channel subunits, are unique. The majority of plant ion channel families exhibit homology to animal genes; such families include both hyperpolarization- and depolarization-activated Shaker-type potassium channels, CLC chloride transporters/channels, cyclic nucleotide-gated channels, and ionotropic glutamate receptor homologs. These plant ion channels offer unique opportunities to analyze the structural mechanisms and functions of ion channels. Here we review gene families of selected plant ion channel classes and discuss unique structure-function aspects and their physiological roles in plant cell signaling and transport.
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Affiliation(s)
- John M. Ward
- Department of Plant Biology, University of Minnesota, St. Paul, Minnesota 55108;
| | - Pascal Mäser
- Institute of Cell Biology, University of Bern, CH-3012 Bern, Switzerland
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section, University of California, San Diego, La Jolla, California 92093;
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Kwak JM, Mäser P, Schroeder JI. The Clickable Guard Cell, Version II: Interactive Model of Guard Cell Signal Transduction Mechanisms and Pathways. THE ARABIDOPSIS BOOK 2008; 6:e0114. [PMID: 22303239 PMCID: PMC3243356 DOI: 10.1199/tab.0114] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Guard cells are located in the leaf epidermis and pairs of guard cells surround and form stomatal pores, which regulate CO(2) influx from the atmosphere into leaves for photosynthetic carbon fixation. Stomatal guard cells also regulate water loss of plants via transpiration to the atmosphere. Signal transduction mechanisms in guard cells integrate a multitude of different stimuli to modulate stomatal apertures. Stomata open in response to light. Stomata close in response to drought stress, elevated CO(2), ozone and low humidity. In response to drought, plants synthesize the hormone abscisic acid (ABA) that triggers closing of stomatal pores. Guard cells have become a highly developed model system for dissecting signal transduction mechanisms in plants and for elucidating how individual signaling mechanisms can interact within a network in a single cell. Many new findings have been made in the last few years. This chapter is an update of an electronic interactive chapter in the previous edition of The Arabidopsis Book (Mäser et al. 2003). Here we focus on mechanisms for which genes and mutations have been characterized, including signaling components for which there is substantial signaling, biochemical and genetic evidence. Ion channels have been shown to represent targets of early signal transduction mechanisms and provide functional signaling and quantitative analysis points to determine where and how mutations affect branches within the guard cell signaling network. Although a substantial number of genes and proteins that function in guard cell signaling have been identified in recent years, there are many more left to be identified and the protein-protein interactions within this network will be an important subject of future research. A fully interactive clickable electronic version of this publication can be accessed at the following web site: http://www-biology.ucsd.edu/labs/schroeder/clickablegc2/. The interactive clickable version includes the following features: Figure 1. Model for the roles of ion channels in ABA signaling.Figure 2. Blue light signaling pathways in guard cells.Figure 3. ABA signaling pathways in guard cells.Figure 1 is linked to explanations that appear upon mouse-over. Figure 2 and Figure 3 are clickable and linked to info boxes, which in turn are linked to TAIR, to relevant abstracts in PubMed, and to updated background explanations from Schroeder et al (2001), used with permission of Annual Reviews of Plant Biology.
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Affiliation(s)
- June M. Kwak
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742
| | - Pascal Mäser
- Institute of Cell Biology, University of Berne, CH-3012 Bern, Switzerland
| | - Julian I. Schroeder
- Division of Biological Sciences, Cell and Developmental Biology Section and Center for Molecular Genetics, University of California, San Diego, La Jolla, California 92093-0116
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Zhang WH, Ryan PR, Sasaki T, Yamamoto Y, Sullivan W, Tyerman SD. Characterization of the TaALMT1 protein as an Al3+-activated anion channel in transformed tobacco (Nicotiana tabacum L.) cells. PLANT & CELL PHYSIOLOGY 2008; 49:1316-30. [PMID: 18676980 DOI: 10.1093/pcp/pcn107] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
TaALMT1 encodes a putative transport protein associated with Al(3+)-activated efflux of malate from wheat root apices. We expressed TaALMT1 in Nicotiana tabacum L. suspension cells and conducted a detailed functional analysis. Protoplasts were isolated for patch-clamping from cells expressing TaALMT1 and from control cells (empty vector transformed). With malate(2-) as the permeant anion in the protoplast, an inward current (anion efflux) that reversed at positive potentials was observed in protoplasts expressing TaALMT1 in the absence of Al(3+). This current was sensitive to the anion channel antagonist niflumate, but insensitive to Gd(3+). External AlCl(3) (50 microM), but not La(3+) and Gd(3+), increased the inward current in TaALMT1-transformed protoplasts. The inward current was highly selective to malate over nitrate and chloride (P(mal) >> P(NO3) >or= P(Cl), P(mal)/P(Cl) >or=18, +/-Al(3+)), under conditions with higher anion concentration internally than externally. The anion currents displayed a voltage and time dependent deactivation at negative voltages. Voltage ramps revealed that inward rectification was caused by the imposed anion gradients. Single channels with conductances between 10 and 17 pS were associated with the deactivation of the current at negative voltages, agreeing with estimates from voltage ramps. This study of the electrophysiological function of the TaALMT1 protein in a plant heterologous expression system provides the first direct evidence that TaALMT1 functions as an Al(3+)-activated malate(2-) channel. We show that the Al(3+)-activated currents measured in TaALMT1-transformed tobacco cells are identical to the Al(3+)-activated currents observed in the root cells of wheat, indicating that TaALMT1 alone is likely to be responsible for those endogenous currents.
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Affiliation(s)
- Wen-Hao Zhang
- Key laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, PR China
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45
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Schönknecht G, Trebacz K. Vacuolar ion channels in the liverwort Conocephalum conicum. PLANT SIGNALING & BEHAVIOR 2008; 3:404-5. [PMID: 19704580 PMCID: PMC2634316 DOI: 10.4161/psb.3.6.5430] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Accepted: 12/14/2007] [Indexed: 05/13/2023]
Abstract
As a liverwort Conocephalum conicum belongs to the oldest terrestrial plants1 and is phylogenetically located between green algae and higher plants. Recent patch-clamp recordings on Conocephalum vacuoles2,3 demonstrate ion channels very similar to higher plants and clearly different from vacuolar ion channels described in green algae. Here we summarize the features of a vacuolar cation channel and a vacuolar anion channel that both are common in terrestrial plants but are not detected in green algae, and we speculate about the molecular identity of these channels in the liverwort Conocephalum.
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Affiliation(s)
- Gerald Schönknecht
- Institute for Plant Biochemistry; Heinrich-Heine-University; Düsseldorf, Germany
| | - Kazimierz Trebacz
- Department of Biophysics; Institute of Biology; Maria Curie-Sklodowska University; Lublin, Poland
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46
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Kovermann P, Meyer S, Hörtensteiner S, Picco C, Scholz-Starke J, Ravera S, Lee Y, Martinoia E. The Arabidopsis vacuolar malate channel is a member of the ALMT family. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 52:1169-80. [PMID: 18005230 DOI: 10.1111/j.1365-313x.2007.03367.x] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
In plants, malate is a central metabolite and fulfills a large number of functions. Vacuolar malate may reach very high concentrations and fluctuate rapidly, whereas cytosolic malate is kept at a constant level allowing optimal metabolism. Recently, a vacuolar malate transporter (Arabidopsis thaliana tonoplast dicarboxylate transporter, AttDT) was identified that did not correspond to the well-characterized vacuolar malate channel. We therefore hypothesized that a member of the aluminum-activated malate transporter (ALMT) gene family could code for a vacuolar malate channel. Using GFP fusion constructs, we could show that AtALMT9 (A. thaliana ALMT9) is targeted to the vacuole. Promoter-GUS fusion constructs demonstrated that this gene is expressed in all organs, but is cell-type specific as GUS activity in leaves was detected nearly exclusively in mesophyll cells. Patch-clamp analysis of an Atalmt9 T-DNA insertion mutant exhibited strongly reduced vacuolar malate channel activity. In order to functionally characterize AtALMT9 as a malate channel, we heterologously expressed this gene in tobacco and in oocytes. Overexpression of AtALMT9-GFP in Nicotiana benthamiana leaves strongly enhanced the malate current densities across the mesophyll tonoplasts. Functional expression of AtALMT9 in Xenopus oocytes induced anion currents, which were clearly distinguishable from endogenous oocyte currents. Our results demonstrate that AtALMT9 is a vacuolar malate channel. Deletion mutants for AtALMT9 exhibit only slightly reduced malate content in mesophyll protoplasts and no visible phenotype, indicating that AttDT and the residual malate channel activity are sufficient to sustain the transport activity necessary to regulate the cytosolic malate homeostasis.
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Affiliation(s)
- Peter Kovermann
- Institute for Plant Biology, University of Zürich, CH-8008 Zürich, Switzerland
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47
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Trebacz K, Schönknecht G, Dziubinska H, Hanaka A. Characteristics of anion channels in the tonoplast of the liverwort Conocephalum conicum. PLANT & CELL PHYSIOLOGY 2007; 48:1747-57. [PMID: 17971334 DOI: 10.1093/pcp/pcm147] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Isolated vacuoles of the liverwort Conocephalum conicum thallus cells were investigated using the patch-clamp technique. At high cytosolic Ca(2+) activities, slowly activating currents were evoked by positive potentials. The currents were conducted by the SV (slow-vacuolar) channel. When isolation of vacuoles was carried out at high Mg(2+) and low Ca(2+) concentration and the same proportion of the cations was kept in the bath, currents were recorded at negative potentials. Once activated, these currents persisted even after replacing Mg(2+) with K(+) in the bath. Sr(2+) and Ba(2+) were also effective activators of the currents. With a Cl(-) gradient, 10 mM in the bath and 100 mM in the lumen, currents were significantly reduced and the current-voltage characteristics shifted towards the reversal potential of Cl(-), indicating Cl(-) selectivity. Currents almost vanished after substituting Cl(-) with gluconate. They were strongly reduced by anion channel inhibitors 4,4'-diisothicyanatostilbene-2,2'-disulfonic acid (DIDS; 1 mM), anthracene-9-carboxylic acid (A9C; 2 mM) and ethacrinic acid (0.5 mM). Single-channel recordings revealed a 32 pS channel activating at negative voltages. It is concluded that the currents at negative potentials are carried by anion channels suitable for conducting anions from the cytosol to the vacuole. The anion channels were weakly calcium dependent, remaining active at physiological calcium concentration. The channels were almost equally permeable to Cl(-), NO3(-) and SO4(2-), and much less permeable to malate(2-). Anion channels did not respond to ATP addition. cAMP (10 microM) had a weak effect on anion channels. Protein kinase A (0.4 U) added to the medium caused no significant effect on anion channels.
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Affiliation(s)
- Kazimierz Trebacz
- Department of Biophysics, Institute of Biology, Maria Curie-Sklodowska University, Akademicka 19, Lublin, Poland.
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48
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Gobert A, Isayenkov S, Voelker C, Czempinski K, Maathuis FJM. The two-pore channel TPK1 gene encodes the vacuolar K+ conductance and plays a role in K+ homeostasis. Proc Natl Acad Sci U S A 2007; 104:10726-31. [PMID: 17563365 PMCID: PMC1965580 DOI: 10.1073/pnas.0702595104] [Citation(s) in RCA: 177] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The Arabidopsis thaliana genome contains five genes that encode two pore K+ (TPK) channels. The most abundantly expressed isoform of this family, TPK1, is expressed at the tonoplast where it mediates K+ -selective currents between cytoplasmic and vacuolar compartments. TPK1 open probability depends on both cytoplasmic Ca2+ and cytoplasmic pH but not on the tonoplast membrane voltage. The channel shows intrinsic rectification and can be blocked by Ba2+, tetraethylammonium, and quinine. TPK1 current was found in all shoot cell types and shows all of the hallmarks of the previously described vacuolar K (VK) tonoplast channel characterized in guard cells. Characterization of TPK1 loss-of-function mutants and TPK1-overexpressing plants shows that TPK1 has a role in intracellular K+ homeostasis affecting seedling growth at high and low ambient K+ levels. In stomata, TPK1 function is consistent with vacuolar K+ release, and removal of this channel leads to slower stomatal closure kinetics. During germination, TPK1 contributes to the radicle development through vacuolar K+ deposition to provide expansion growth or in the redistribution of essential minerals.
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Affiliation(s)
- Anthony Gobert
- *Department of Biology Area 9, University of York, York YO10 5DD, United Kingdom; and
| | - Stanislav Isayenkov
- *Department of Biology Area 9, University of York, York YO10 5DD, United Kingdom; and
| | - Camilla Voelker
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, Haus 20, D-14476 Golm, Germany
| | - Katrin Czempinski
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Strasse 24-25, Haus 20, D-14476 Golm, Germany
| | - Frans J. M. Maathuis
- *Department of Biology Area 9, University of York, York YO10 5DD, United Kingdom; and
- To whom correspondence should be addressed. E-mail:
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de Angeli A, Thomine S, Frachisse JM, Ephritikhine G, Gambale F, Barbier-Brygoo H. Anion channels and transporters in plant cell membranes. FEBS Lett 2007; 581:2367-74. [PMID: 17434490 DOI: 10.1016/j.febslet.2007.04.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2007] [Revised: 04/01/2007] [Accepted: 04/02/2007] [Indexed: 11/29/2022]
Abstract
Anion channels/transporters appear as key players in signaling pathways leading to the adaptation of plant cells to abiotic and biotic environmental stresses, in the control of metabolism and in the maintenance of electrochemical gradients. Focusing on the most recent advances, this review aims at providing a description of the role of these channels in various physiological functions such as control of stomatal movements, plant-pathogen interaction, xylem loading, compartmentalization of metabolites and coupling with proton gradients. These functions have been demonstrated by a combination of electrophysiology, pharmacology and genetics approaches, the key issue being to identify the corresponding proteins and genes.
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Affiliation(s)
- Alexis de Angeli
- Institut des Sciences du Végétal, UPR 2355, CNRS, 1 Avenue de la Terrasse, 91198 Gif sur Yvette Cedex, France
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50
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Neuhaus HE. Transport of primary metabolites across the plant vacuolar membrane. FEBS Lett 2007; 581:2223-6. [PMID: 17307167 DOI: 10.1016/j.febslet.2007.02.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2007] [Revised: 02/02/2007] [Accepted: 02/03/2007] [Indexed: 11/29/2022]
Abstract
Mesophyll cells and most types of storage cells harbor large central vacuoles representing the main cellular store for sugars and other primary metabolites like carboxylic- or and amino acids. The general biochemical characteristics of sugar transport across the vacuolar membrane are already known since a couple of years but only recently the first tonoplast sugar carriers have been identified on the molecular level. A candidate sucrose carrier has been identified in a proteomic approach. In Arabidopsis, the tonoplast monosaccharide transporters (TMT) represent a small protein family comprising only three members, which reside in the vacuolar membrane. Two of three tmt genes are induced upon cold, drought or salt stress and tmt knock out mutants exhibit altered monosaccharide levels upon cold induction. These observations indicate that TMT proteins represent the first examples of tonoplast sugar carriers involved in the cellular response upon osmotic stress stimuli.
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Affiliation(s)
- H Ekkehard Neuhaus
- Pflanzenphysiologie, Technische Universitat Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern, Germany.
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