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Hanin M, Ebel C, Ngom M, Laplaze L, Masmoudi K. New Insights on Plant Salt Tolerance Mechanisms and Their Potential Use for Breeding. FRONTIERS IN PLANT SCIENCE 2016; 7:1787. [PMID: 27965692 PMCID: PMC5126725 DOI: 10.3389/fpls.2016.01787] [Citation(s) in RCA: 289] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 11/14/2016] [Indexed: 05/18/2023]
Abstract
Soil salinization is a major threat to agriculture in arid and semi-arid regions, where water scarcity and inadequate drainage of irrigated lands severely reduce crop yield. Salt accumulation inhibits plant growth and reduces the ability to uptake water and nutrients, leading to osmotic or water-deficit stress. Salt is also causing injury of the young photosynthetic leaves and acceleration of their senescence, as the Na+ cation is toxic when accumulating in cell cytosol resulting in ionic imbalance and toxicity of transpiring leaves. To cope with salt stress, plants have evolved mainly two types of tolerance mechanisms based on either limiting the entry of salt by the roots, or controlling its concentration and distribution. Understanding the overall control of Na+ accumulation and functional studies of genes involved in transport processes, will provide a new opportunity to improve the salinity tolerance of plants relevant to food security in arid regions. A better understanding of these tolerance mechanisms can be used to breed crops with improved yield performance under salinity stress. Moreover, associations of cultures with nitrogen-fixing bacteria and arbuscular mycorrhizal fungi could serve as an alternative and sustainable strategy to increase crop yields in salt-affected fields.
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Affiliation(s)
- Moez Hanin
- Laboratoire de Biotechnologie et Amélioration des Plantes, Centre de Biotechnologie de SfaxSfax, Tunisia
- Institut Supérieur de Biotechnologie, Université de SfaxSfax, Tunisia
| | - Chantal Ebel
- Laboratoire de Biotechnologie et Amélioration des Plantes, Centre de Biotechnologie de SfaxSfax, Tunisia
- Institut Supérieur de Biotechnologie, Université de SfaxSfax, Tunisia
| | - Mariama Ngom
- Laboratoire mixte international Adaptation des Plantes et microorganismes associés aux Stress EnvironnementauxDakar, Senegal
- Laboratoire Commun de Microbiologie, Institut de Recherche pour le Développement/Institut Sénégalais de Recherches Agricoles/Université Cheikh Anta DiopDakar, Senegal
| | - Laurent Laplaze
- Laboratoire mixte international Adaptation des Plantes et microorganismes associés aux Stress EnvironnementauxDakar, Senegal
- Laboratoire Commun de Microbiologie, Institut de Recherche pour le Développement/Institut Sénégalais de Recherches Agricoles/Université Cheikh Anta DiopDakar, Senegal
- Institut de Recherche pour le Développement, Unités Mixtes de Recherche, Diversité, Adaptation, Développement des Plantes (DIADE), MontpellierFrance
| | - Khaled Masmoudi
- Department of Aridland, College of Food and Agriculture, United Arab Emirates UniversityAl Ain, UAE
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202
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Kang P, Bao AK, Kumar T, Pan YQ, Bao Z, Wang F, Wang SM. Assessment of Stress Tolerance, Productivity, and Forage Quality in T 1 Transgenic Alfalfa Co-overexpressing ZxNHX and ZxVP1-1 from Zygophyllum xanthoxylum. FRONTIERS IN PLANT SCIENCE 2016; 7:1598. [PMID: 27833624 PMCID: PMC5081344 DOI: 10.3389/fpls.2016.01598] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/10/2016] [Indexed: 05/21/2023]
Abstract
Salinization, desertification, and soil nutrient deprivation are threatening the production of alfalfa (Medicago sativa L.) in northern China. We have previously generated T0 transgenic alfalfa co-overexpressing Zygophyllum xanthoxylum ZxNHX and ZxVP1-1 genes with enhanced salt and drought tolerance. To further develop this excellent breeding material into the new forage cultivar, stress tolerance, productivity, and forage quality of T1 transgenic alfalfa (GM) were assessed in this study. The GM inherited the traits of salt and drought tolerance from T0 generation. Most importantly, co-overexpression of ZxNHX and ZxVP1-1 enhanced the tolerance to Pi deficiency in GM, which was associated with more Pi accumulation in plants. Meanwhile, T1 transgenic alfalfa developed a larger root system with increased root size, root dry weight and root/shoot ratio, which may be one important reason for the improvement of phosphorus nutrition and high biomass accumulation in GM under various conditions. GM also accumulated more crude protein, crude fiber, crude fat, and crude ash than wild-type (WT) plants, especially under stress conditions and in the field. More interestingly, the crude fat contents sharply dropped in WT (by 66-74%), whereas showed no change or decreased less in GM, when subjected to salinity, drought or low-Pi. Our results indicate that T1 transgenic alfalfa co-overexpressing ZxNHX and ZxVP1-1 shows stronger stress tolerance, higher productivity and better forage quality. This study provides a solid foundation for creating the alfalfa cultivars with high yield, good quality and wide adaptability on saline, dry, and nutrient-deprived marginal lands of northern China.
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Affiliation(s)
| | - Ai-Ke Bao
- *Correspondence: Ai-Ke Bao, Suo-Min Wang,
| | | | | | | | | | - Suo-Min Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
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203
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Chen Y, Ma J, Miller AJ, Luo B, Wang M, Zhu Z, Ouwerkerk PBF. OsCHX14 is Involved in the K+ Homeostasis in Rice (Oryza sativa) Flowers. PLANT & CELL PHYSIOLOGY 2016; 57:1530-1543. [PMID: 27903806 DOI: 10.1093/pcp/pcw088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Accepted: 04/26/2016] [Indexed: 05/22/2023]
Abstract
Previously we showed in the osjar1 mutants that the lodicule senescence which controls the closing of rice flowers was delayed. This resulted in florets staying open longer when compared with the wild type. The gene OsJAR1 is silenced in osjar1 mutants and is a key member of the jasmonic acid (JA) signaling pathway. We found that K concentrations in lodicules and flowers of osjar1-2 were significantly elevated compared with the wild type, indicating that K+ homeostasis may play a role in regulating the closure of rice flowers. The cation/H+ exchanger (CHX) family from rice was screened for potential K+ transporters involved as many members of this family in Arabidopsis were exclusively or preferentially expressed in flowers. Expression profiling confirmed that among 17 CHX genes in rice, OsCHX14 was the only member that showed an expression polymorphism, not only in osjar1 mutants but also in RNAi (RNA interference) lines of OsCOI1, another key member of the JA signaling pathway. This suggests that the expression of OsCHX14 is regulated by the JA signaling pathway. Green fluorescent protein (GFP)-tagged OsCHX14 protein was preferentially localized to the endoplasmic reticulum. Promoter-β-glucuronidase (GUS) analysis of transgenic rice revealed that OsCHX14 is mainly expressed in lodicules and the region close by throughout the flowering process. Characterization in yeast and Xenopus laevis oocytes verified that OsCHX14 is able to transport K+, Rb+ and Cs+ in vivo. Our data suggest that OsCHX14 may play an important role in K+ homeostasis during flowering in rice.
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Affiliation(s)
- Yi Chen
- Institute of Biology (IBL), Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE, PO Box 9505, 2300 RA Leiden, The Netherlands
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, UK
- Department of Sustainable Soils and Grassland Systems, Rothamsted Research, Harpenden AL5 2JQ, UK
| | - Jingkun Ma
- Department of Cell and Developmental Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Anthony J Miller
- Department of Metabolic Biology, John Innes Centre, Norwich NR4 7UH, UK
| | - Bingbing Luo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Low-Middle Reaches of the Yangtze River, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 219500, China
| | - Mei Wang
- Institute of Biology (IBL), Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE, PO Box 9505, 2300 RA Leiden, The Netherlands
- TNO Quality of Life, Zernikedreef 9, 2333 CK Leiden, PO Box 2215, 2301 CE Leiden, The Netherlands
| | - Zhen Zhu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing, 100101 China
| | - Pieter B F Ouwerkerk
- Institute of Biology (IBL), Leiden University, Sylvius Laboratory, Sylviusweg 72, 2333 BE, PO Box 9505, 2300 RA Leiden, The Netherlands
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204
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Nieves-Cordones M, Al Shiblawi FR, Sentenac H. Roles and Transport of Sodium and Potassium in Plants. Met Ions Life Sci 2016; 16:291-324. [PMID: 26860305 DOI: 10.1007/978-3-319-21756-7_9] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The two alkali cations Na(+) and K(+) have similar relative abundances in the earth crust but display very different distributions in the biosphere. In all living organisms, K(+) is the major inorganic cation in the cytoplasm, where its concentration (ca. 0.1 M) is usually several times higher than that of Na(+). Accumulation of Na(+) at high concentrations in the cytoplasm results in deleterious effects on cell metabolism, e.g., on photosynthetic activity in plants. Thus, Na(+) is compartmentalized outside the cytoplasm. In plants, it can be accumulated at high concentrations in vacuoles, where it is used as osmoticum. Na(+) is not an essential element in most plants, except in some halophytes. On the other hand, it can be a beneficial element, by replacing K(+) as vacuolar osmoticum for instance. In contrast, K(+) is an essential element. It is involved in electrical neutralization of inorganic and organic anions and macromolecules, pH homeostasis, control of membrane electrical potential, and the regulation of cell osmotic pressure. Through the latter function in plants, it plays a role in turgor-driven cell and organ movements. It is also involved in the activation of enzymes, protein synthesis, cell metabolism, and photosynthesis. Thus, plant growth requires large quantities of K(+) ions that are taken up by roots from the soil solution, and then distributed throughout the plant. The availability of K(+) ions in the soil solution, slowly released by soil particles and clays, is often limiting for optimal growth in most natural ecosystems. In contrast, due to natural salinity or irrigation with poor quality water, detrimental Na(+) concentrations, toxic for all crop species, are present in many soils, representing 6 % to 10 % of the earth's land area. Three families of ion channels (Shaker, TPK/KCO, and TPC) and 3 families of transporters (HAK, HKT, and CPA) have been identified so far as contributing to K(+) and Na(+) transport across the plasmalemma and internal membranes, with high or low ionic selectivity. In the model plant Arabidopsis thaliana, these families gather at least 70 members. Coordination of the activities of these systems, at the cell and whole plant levels, ensures plant K(+) nutrition, use of Na(+) as a beneficial element, and adaptation to saline conditions.
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Affiliation(s)
- Manuel Nieves-Cordones
- Laboratory of Plant Biochemistry and Molecular Physiology, UMR BPMP CNRS/INRA/MontpellierSupAgro, University of Montpellier, INRA, Place Viala, F-34060, Montpellier cedex 1, France
| | - Fouad Razzaq Al Shiblawi
- Laboratory of Plant Biochemistry and Molecular Physiology, UMR BPMP CNRS/INRA/MontpellierSupAgro, University of Montpellier, INRA, Place Viala, F-34060, Montpellier cedex 1, France
| | - Hervé Sentenac
- Laboratory of Plant Biochemistry and Molecular Physiology, UMR BPMP CNRS/INRA/MontpellierSupAgro, University of Montpellier, INRA, Place Viala, F-34060, Montpellier cedex 1, France.
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205
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Zhu J, Ying SH, Feng MG. The Na + /H + antiporter Nhx1 controls vacuolar fusion indispensible for life cycles in vitro and in vivo in a fungal insect pathogen. Environ Microbiol 2016; 18:3884-3895. [PMID: 27112237 DOI: 10.1111/1462-2920.13359] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 04/21/2016] [Indexed: 01/10/2023]
Abstract
The sole Na+ /H+ antiporter Nhx1 has been generally unexplored in filamentous fungi. We characterized Nhx1 in the entomopathogenic fungus Beauveria bassiana. An eGFP-tagged Nhx1 fusion accumulated in small punctuate structures, presumably endosomal and trans-Golgi network compartments, between septum and tubular vacuole of each wild-type cell stained with a vacuole-specific dye. Deletion of nhx1 resulted in significant acidification and severe fusion defect in vacuoles, which were fragmented and distinct from large or tubular wild-type vacuoles. The deletion also caused a drastic reduction in aerial conidiation or submerged blastospore production and more severe defect in vegetative growth than in conidial germination. The Δnhx1 mutant became more sensitive to high osmolarity, heat shock and several metal ions during growth but its conidia showed increased UV-B tolerance. Intriguingly, Δnhx1 was unable to infect a model insect through cuticle penetration or intrahaemocoel injection because it produced much less biomass and cuticle-degrading enzymes in a minimal broth and failed to form blastospores in the insect haemolymph. All changes were completely or largely restored by targeted nhx1 complementation. Our results provide novel insight into an indispensability of Nhx1 for not only vacuolar fusion but also life cycles in vitro and in vivo in B. bassiana.
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Affiliation(s)
- Jing Zhu
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Sheng-Hua Ying
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
| | - Ming-Guang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, People's Republic of China
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206
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Zhou H, Qi K, Liu X, Yin H, Wang P, Chen J, Wu J, Zhang S. Genome-wide identification and comparative analysis of the cation proton antiporters family in pear and four other Rosaceae species. Mol Genet Genomics 2016; 291:1727-42. [DOI: 10.1007/s00438-016-1215-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 05/06/2016] [Indexed: 11/28/2022]
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207
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Czerny DD, Padmanaban S, Anishkin A, Venema K, Riaz Z, Sze H. Protein architecture and core residues in unwound α-helices provide insights to the transport function of plant AtCHX17. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1983-1998. [PMID: 27179641 DOI: 10.1016/j.bbamem.2016.05.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/13/2016] [Accepted: 05/08/2016] [Indexed: 01/27/2023]
Abstract
Using Arabidopsis thaliana AtCHX17 as an example, we combine structural modeling and mutagenesis to provide insights on its protein architecture and transport function which is poorly characterized. This approach is based on the observation that protein structures are significantly more conserved in evolution than linear sequences, and mechanistic similarities among diverse transporters are emerging. Two homology models of AtCHX17 were obtained that show a protein fold similar to known structures of bacterial Na(+)/H(+) antiporters, EcNhaA and TtNapA. The distinct secondary and tertiary structure models highlighted residues at positions potentially important for CHX17 activity. Mutagenesis showed that asparagine-N200 and aspartate-D201 inside transmembrane5 (TM5), and lysine-K355 inside TM10 are critical for AtCHX17 activity. We reveal previously unrecognized threonine-T170 and lysine-K383 as key residues at unwound regions in the middle of TM4 and TM11 α-helices, respectively. Mutation of glutamate-E111 located near the membrane surface inhibited AtCHX17 activity, suggesting a role in pH sensing. The long carboxylic tail of unknown purpose has an alternating β-sheet and α-helix secondary structure that is conserved in prokaryote universal stress proteins. These results support the overall architecture of AtCHX17 and identify D201, N200 and novel residues T170 and K383 at the functional core which likely participates in ion recognition, coordination and/or translocation, similar to characterized cation/H(+) exchangers. The core of AtCHX17 models according to EcNhaA and TtNapA templates faces inward and outward, respectively, which may reflect two conformational states of the alternating access transport mode for proteins belonging to the plant CHX family.
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Affiliation(s)
- Daniel D Czerny
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA
| | - Senthilkumar Padmanaban
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA
| | - Andriy Anishkin
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Kees Venema
- Dpto de Bioquímica, Biología Celular y Molecular de Plantas, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, c/. Profesor Albareda 1, 18008Granada, Spain
| | - Zoya Riaz
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA
| | - Heven Sze
- Department of Cell Biology and Molecular Genetics (DC, SP, ZR, HS), University of Maryland, College Park, MD 20742, USA; Maryland Agricultural Experiment Station, Department of Plant Science and Landscape Architecture (HS), University of Maryland, College Park, MD 20742, USA.
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208
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Monihan SM, Magness CA, Yadegari R, Smith SE, Schumaker KS. Arabidopsis CALCINEURIN B-LIKE10 Functions Independently of the SOS Pathway during Reproductive Development in Saline Conditions. PLANT PHYSIOLOGY 2016; 171:369-79. [PMID: 26979332 PMCID: PMC4854721 DOI: 10.1104/pp.16.00334] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 03/12/2016] [Indexed: 05/05/2023]
Abstract
The accumulation of sodium in soil (saline conditions) negatively affects plant growth and development. The Salt Overly Sensitive (SOS) pathway in Arabidopsis (Arabidopsis thaliana) functions to remove sodium from the cytosol during vegetative development preventing its accumulation to toxic levels. In this pathway, the SOS3 and CALCINEURIN B-LIKE10 (CBL10) calcium sensors interact with the SOS2 protein kinase to activate sodium/proton exchange at the plasma membrane (SOS1) or vacuolar membrane. To determine if the same pathway functions during reproductive development in response to salt, fertility was analyzed in wild type and the SOS pathway mutants grown in saline conditions. In response to salt, CBL10 functions early in reproductive development before fertilization, while SOS1 functions mostly after fertilization when seed development begins. Neither SOS2 nor SOS3 function in reproductive development in response to salt. Loss of CBL10 function resulted in reduced anther dehiscence, shortened stamen filaments, and aborted pollen development. In addition, cbl10 mutant pistils could not sustain the growth of wild-type pollen tubes. These results suggest that CBL10 is critical for reproductive development in the presence of salt and that it functions in different pathways during vegetative and reproductive development.
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Affiliation(s)
- Shea M Monihan
- School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721
| | - Courtney A Magness
- School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721
| | - Ramin Yadegari
- School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721
| | - Steven E Smith
- School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721
| | - Karen S Schumaker
- School of Plant Sciences (S.M.M., C.A.M., R.Y., K.S.S.) and School of Natural Resources and the Environment (S.E.S.), University of Arizona, Tucson, Arizona 85721
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209
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Janda T, Darko É, Shehata S, Kovács V, Pál M, Szalai G. Salt acclimation processes in wheat. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 101:68-75. [PMID: 26854409 DOI: 10.1016/j.plaphy.2016.01.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2016] [Revised: 01/28/2016] [Accepted: 01/29/2016] [Indexed: 05/24/2023]
Abstract
Young wheat plants (Triticum aestivum L. cv. Mv Béres) were exposed to 0 or 25 mM NaCl for 11 days (salt acclimation). Thereafter the plants were irrigated with 500 mM NaCl for 5 days (salt stress). Irrigating the plants with a low concentration of NaCl successfully led to a reduction in chlorotic symptoms and in the impairment of the photosynthetic processes when the plants were exposed to subsequent high-dose salt treatment. After exposure to a high concentration of NaCl there was no difference in leaf Na content between the salt-acclimated and non-acclimated plants, indicating that salt acclimation did not significantly modify Na transport to the shoots. While the polyamine level was lower in salt-treated plants than in the control, salt acclimation led to increased osmotic potential in the leaves. Similarly, the activities of certain antioxidant enzymes, namely glutathione reductase, catalase and ascorbate peroxidase, were significantly higher in salt-acclimated plants. The results also suggest that while SOS1, SOS2 or NHX2 do not play a decisive role in the salt acclimation processes in young wheat plants; another stress-related gene, WALI6, may contribute to the success of the salt acclimation processes. The present study suggested that the responses of wheat plants to acclimation with low level of salt and to treatment with high doses of salt may be fundamentally different.
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Affiliation(s)
- Tibor Janda
- Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-2462 Martonvásár, POB 19, Hungary.
| | - Éva Darko
- Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-2462 Martonvásár, POB 19, Hungary.
| | - Sami Shehata
- National Research Centre, El Buhouth St., Dokki, Cairo, Egypt.
| | - Viktória Kovács
- Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-2462 Martonvásár, POB 19, Hungary.
| | - Magda Pál
- Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-2462 Martonvásár, POB 19, Hungary.
| | - Gabriella Szalai
- Agricultural Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, H-2462 Martonvásár, POB 19, Hungary.
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210
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Bao AK, Du BQ, Touil L, Kang P, Wang QL, Wang SM. Co-expression of tonoplast Cation/H(+) antiporter and H(+)-pyrophosphatase from xerophyte Zygophyllum xanthoxylum improves alfalfa plant growth under salinity, drought and field conditions. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:964-75. [PMID: 26268400 DOI: 10.1111/pbi.12451] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 07/10/2015] [Indexed: 05/20/2023]
Abstract
Salinity and drought are major environmental factors limiting the growth and productivity of alfalfa worldwide as this economically important legume forage is sensitive to these kinds of abiotic stress. In this study, transgenic alfalfa lines expressing both tonoplast NXH and H(+)-PPase genes, ZxNHX and ZxVP1-1 from the xerophyte Zygophyllum xanthoxylum L., were produced via Agrobacterium tumefaciens-mediated transformation. Compared with wild-type (WT) plants, transgenic alfalfa plants co-expressing ZxNHX and ZxVP1-1 grew better with greater plant height and dry mass under normal or stress conditions (NaCl or water-deficit) in the greenhouse. The growth performance of transgenic alfalfa plants was associated with more Na(+), K(+) and Ca(2+) accumulation in leaves and roots, as a result of co-expression of ZxNHX and ZxVP1-1. Cation accumulation contributed to maintaining intracellular ions homoeostasis and osmoregulation of plants and thus conferred higher leaf relative water content and greater photosynthesis capacity in transgenic plants compared to WT when subjected to NaCl or water-deficit stress. Furthermore, the transgenic alfalfa co-expressing ZxNHX and ZxVP1-1 also grew faster than WT plants under field conditions, and most importantly, exhibited enhanced photosynthesis capacity by maintaining higher net photosynthetic rate, stomatal conductance, and water-use efficiency than WT plants. Our results indicate that co-expression of tonoplast NHX and H(+)-PPase genes from a xerophyte significantly improved the growth of alfalfa, and enhanced its tolerance to high salinity and drought. This study laid a solid basis for reclaiming and restoring saline and arid marginal lands as well as improving forage yield in northern China.
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Affiliation(s)
- Ai-Ke Bao
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Bao-Qiang Du
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
- Lanzhou Animal Husbandry and Veterinary Institute, Lanzhou, China
| | - Leila Touil
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
- Laboratory of arid and oasis cropping, Institute of Arid Area (IRA), Medenine, Tunisia
| | - Peng Kang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Qiang-Long Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Suo-Min Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
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211
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Weigl S, Brandt W, Langhammer R, Roos W. The Vacuolar Proton-Cation Exchanger EcNHX1 Generates pH Signals for the Expression of Secondary Metabolism in Eschscholzia californica. PLANT PHYSIOLOGY 2016; 170:1135-48. [PMID: 26578709 PMCID: PMC4734569 DOI: 10.1104/pp.15.01570] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 11/13/2015] [Indexed: 05/26/2023]
Abstract
Cell cultures of Eschscholzia californica react to a fungal elicitor by the overproduction of antimicrobial benzophenanthridine alkaloids. The signal cascade toward the expression of biosynthetic enzymes includes (1) the activation of phospholipase A2 at the plasma membrane, resulting in a peak of lysophosphatidylcholine, and (2) a subsequent, transient efflux of vacuolar protons, resulting in a peak of cytosolic H(+). This study demonstrates that one of the Na(+)/H(+) antiporters acting at the tonoplast of E. californica cells mediates this proton flux. Four antiporter-encoding genes were isolated and cloned from complementary DNA (EcNHX1-EcNHX4). RNA interference-based, simultaneous silencing of EcNHX1, EcNHX3, and EcNHX4 resulted in stable cell lines with largely diminished capacities of (1) sodium-dependent efflux of vacuolar protons and (2) elicitor-triggered overproduction of alkaloids. Each of the four EcNHX genes of E. californica reconstituted the lack of Na(+)-dependent H(+) efflux in a Δnhx null mutant of Saccharomyces cerevisiae. Only the yeast strain transformed with and expressing the EcNHX1 gene displayed Na(+)-dependent proton fluxes that were stimulated by lysophosphatidylcholine, thus giving rise to a net efflux of vacuolar H(+). This finding was supported by three-dimensional protein homology models that predict a plausible recognition site for lysophosphatidylcholine only in EcNHX1. We conclude that the EcNHX1 antiporter functions in the elicitor-initiated expression of alkaloid biosynthetic genes by recruiting the vacuolar proton pool for the signaling process.
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Affiliation(s)
- Sophie Weigl
- Institute of Pharmacy, Department of Pharmaceutical Biology, Laboratory of Molecular Cell Biology (S.W., W.R.), and Institute of Genetics, Department of Molecular Genetics (R.L.), Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; andLeibniz Institute of Plant Biochemistry, Department of Bioorganic Chemistry, 06120 Halle (Saale), Germany (W.B.)
| | - Wolfgang Brandt
- Institute of Pharmacy, Department of Pharmaceutical Biology, Laboratory of Molecular Cell Biology (S.W., W.R.), and Institute of Genetics, Department of Molecular Genetics (R.L.), Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; andLeibniz Institute of Plant Biochemistry, Department of Bioorganic Chemistry, 06120 Halle (Saale), Germany (W.B.)
| | - Renate Langhammer
- Institute of Pharmacy, Department of Pharmaceutical Biology, Laboratory of Molecular Cell Biology (S.W., W.R.), and Institute of Genetics, Department of Molecular Genetics (R.L.), Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; andLeibniz Institute of Plant Biochemistry, Department of Bioorganic Chemistry, 06120 Halle (Saale), Germany (W.B.)
| | - Werner Roos
- Institute of Pharmacy, Department of Pharmaceutical Biology, Laboratory of Molecular Cell Biology (S.W., W.R.), and Institute of Genetics, Department of Molecular Genetics (R.L.), Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; andLeibniz Institute of Plant Biochemistry, Department of Bioorganic Chemistry, 06120 Halle (Saale), Germany (W.B.)
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212
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Shabala S, Bose J, Fuglsang AT, Pottosin I. On a quest for stress tolerance genes: membrane transporters in sensing and adapting to hostile soils. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:1015-31. [PMID: 26507891 DOI: 10.1093/jxb/erv465] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Abiotic stresses such as salinity, drought, and flooding severely limit food and fibre production and result in penalties of in excess of US$100 billion per annum to the agricultural sector. Improved abiotic stress tolerance to these environmental constraints via traditional or molecular breeding practices requires a good understanding of the physiological and molecular mechanisms behind roots sensing of hostile soils, as well as downstream signalling cascades to effectors mediating plant adaptive responses to the environment. In this review, we discuss some common mechanisms conferring plant tolerance to these three major abiotic stresses. Central to our discussion are: (i) the essentiality of membrane potential maintenance and ATP production/availability and its use for metabolic versus adaptive responses; (ii) reactive oxygen species and Ca(2+) 'signatures' mediating stress signalling; and (iii) cytosolic K(+) as the common denominator of plant adaptive responses. We discuss in detail how key plasma membrane and tonoplast transporters are regulated by various signalling molecules and processes observed in plants under stress conditions (e.g. changes in membrane potential; cytosolic pH and Ca(2+); reactive oxygen species; polyamines; abscisic acid) and how these stress-induced changes are related to expression and activity of specific ion transporters. The reported results are then discussed in the context of strategies for breeding crops with improved abiotic stress tolerance. We also discuss a classical trade-off between tolerance and yield, and possible avenues for resolving this dilemma.
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Affiliation(s)
- Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas 7001, Australia
| | - Jayakumar Bose
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas 7001, Australia ARC Centre of Excellence in Plant Energy Biology, School of Agriculture, Food and Wine, University of Adelaide, PMB 1, Glen Osmond, SA 5064, Australia
| | - Anja Thoe Fuglsang
- Department of Plant and Environmental Science, University of Copenhagen, DK-1871 Frederiksberg, Denmark
| | - Igor Pottosin
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas 7001, Australia Centro Universitario de Investigaciones Biomédicas, Universidad de Colima, 28045 Colima, México
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213
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Cao B, Long D, Zhang M, Liu C, Xiang Z, Zhao A. Molecular characterization and expression analysis of the mulberry Na(+)/H(+) exchanger gene family. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 99:49-58. [PMID: 26730882 DOI: 10.1016/j.plaphy.2015.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 12/16/2015] [Accepted: 12/16/2015] [Indexed: 06/05/2023]
Abstract
Na(+)/H(+) exchangers (NHXs) have important roles in cellular pH, and Na(+) and K(+) homeostasis in plants. Mulberry is not only an important traditional economic woody plant known for its leaves, which are the exclusive food source of the silkworm Bombyx mori, but it can also adapt to many different adverse conditions, including saline environments. However, little is known about the NHXs in this important perennial tree. In this study, we identified and cloned seven putative NHX gene family members from Morus atropurpurea based on a genome-wide analysis of the Morus genome database. A phylogenetic analysis and genomic organization of mulberry NHXs suggested that the mulberry NHX family forms three distinct subgroups. Transcriptome data and real-time PCR of different mulberry varieties under normal culture conditions revealed that the mulberry NHX family has a different tissue-specific pattern in the two mulberry species. The MaNHX genes' expression analyses under different stresses (salt and drought) and signal molecules (abscisic acid, salicylic acid, hydrogen peroxide and methyl jasmonate) revealed that MaNHXs not only could be induced by salt, drought and abscisic acid as describe in the literature, but were also induced by other signal molecules, which indicated that MaNHX members exhibited diverse and complicated expression patterns in different mulberry tissues under various abiotic stresses, phytohormones and plant signaling molecules. Our results provide some insights into new and emerging cellular and physiological functions of this group of H(+)-coupled cation exchangers, beyond their function in salt tolerance, and also provide the basis for further characterizations of MaNHXs' physiological functions.
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Affiliation(s)
- Boning Cao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Dingpei Long
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Meng Zhang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Changying Liu
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Zhonghuai Xiang
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China
| | - Aichun Zhao
- State Key Laboratory of Silkworm Genome Biology, Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing 400716, China.
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214
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Li P, Zhang G, Gonzales N, Guo Y, Hu H, Park S, Zhao J. Ca(2+) -regulated and diurnal rhythm-regulated Na(+) /Ca(2+) exchanger AtNCL affects flowering time and auxin signalling in Arabidopsis. PLANT, CELL & ENVIRONMENT 2016; 39:377-92. [PMID: 26296956 DOI: 10.1111/pce.12620] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Revised: 07/09/2015] [Accepted: 07/30/2015] [Indexed: 05/21/2023]
Abstract
Calcium (Ca(2+) ) is vital for plant growth, development, hormone response and adaptation to environmental stresses, yet the mechanisms regulating plant cytosolic Ca(2+) homeostasis are not fully understood. Here, we characterize an Arabidopsis Ca(2+) -regulated Na(+) /Ca(2+) exchanger AtNCL that regulates Ca(2+) and multiple physiological processes. AtNCL was localized to the tonoplast in yeast and plant cells. AtNCL appeared to mediate sodium (Na(+) ) vacuolar sequestration and meanwhile Ca(2+) release. The EF-hand domains within AtNCL regulated Ca(2+) binding and transport of Ca(2+) and Na(+) . Plants with diminished AtNCL expression were more tolerant to high CaCl2 but more sensitive to both NaCl and auxin; heightened expression of AtNCL rendered plants more sensitive to CaCl2 but tolerant to NaCl. AtNCL expression appeared to be regulated by the diurnal rhythm and suppressed by auxin. DR5::GUS expression and root responses to auxin were altered in AtNCL mutants. The auxin-induced suppression of AtNCL was attenuated in SLR/IAA14 and ARF6/8 mutants. The mutants with altered AtNCL expression also altered flowering time and FT and CO expression; FT may mediate AtNCL-regulated flowering time change. Therefore, AtNCL is a vacuolar Ca(2+) -regulated Na(+) /Ca(2+) exchanger that regulates auxin responses and flowering time.
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Affiliation(s)
- Penghui Li
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China
| | - Gaoyang Zhang
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China
| | - Naomi Gonzales
- Children's Nutrition Research Center, USDA/ARS, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Yingqing Guo
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China
- Children's Nutrition Research Center, USDA/ARS, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Honghong Hu
- College of Life Science and technology, Huazhong Agricultural University, Wuhan, 430075, China
| | - Sunghun Park
- Department of Horticulture, Forestry and Recreation Resources, Kansas State University, Manhattan, KS, 66506, USA
| | - Jian Zhao
- College of Plant Science & Technology, Huazhong Agricultural University, Wuhan, 430075, China
- Children's Nutrition Research Center, USDA/ARS, Baylor College of Medicine, Houston, TX, 77030, USA
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215
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Amin USM, Biswas S, Elias SM, Razzaque S, Haque T, Malo R, Seraj ZI. Enhanced Salt Tolerance Conferred by the Complete 2.3 kb cDNA of the Rice Vacuolar Na(+)/H(+) Antiporter Gene Compared to 1.9 kb Coding Region with 5' UTR in Transgenic Lines of Rice. FRONTIERS IN PLANT SCIENCE 2016; 7:14. [PMID: 26834778 PMCID: PMC4724728 DOI: 10.3389/fpls.2016.00014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Accepted: 01/07/2016] [Indexed: 05/23/2023]
Abstract
Soil salinity is one of the most challenging problems that restricts the normal growth and production of rice worldwide. It has therefore become very important to produce more saline tolerant rice varieties. This study shows constitutive over-expression of the vacuolar Na(+)/H(+) antiporter gene (OsNHX1) from the rice landrace (Pokkali) and attainment of enhanced level of salinity tolerance in transgenic rice plants. It also shows that inclusion of the complete un-translated regions (UTRs) of the alternatively spliced OsNHX1 gene provides a higher level of tolerance to the transgenic rice. Two separate transformation events of the OsNHX1 gene, one with 1.9 kb region containing the 5' UTR with CDS and the other of 2.3 kb, including 5' UTR, CDS, and the 3' UTR regions were performed. The transgenic plants with these two different constructs were advanced to the T3 generation and physiological and molecular screening of homozygous plants was conducted at seedling and reproductive stages under salinity (NaCl) stress. Both transgenic lines were observed to be tolerant compared to WT plants at both physiological stages. However, the transgenic lines containing the CDS with both the 5' and 3' UTR were significantly more tolerant compared to the transgenic lines containing OsNHX1 gene without the 3' UTR. At the seedling stage at 12 dS/m stress, the chlorophyll content was significantly higher (P < 0.05) and the electrolyte leakage significantly lower (P < 0.05) in the order 2.3 kb > 1.9 kb > and WT lines. Yield in g/plant in the best line from the 2.3 kb plants was significantly more (P < 0.01) compared, respectively, to the best 1.9 kb line and WT plants at stress of 6 dS/m. Transformation with the complete transcripts rather than the CDS may therefore provide more durable level of tolerance.
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216
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Wang WS, Zhao XQ, Li M, Huang LY, Xu JL, Zhang F, Cui YR, Fu BY, Li ZK. Complex molecular mechanisms underlying seedling salt tolerance in rice revealed by comparative transcriptome and metabolomic profiling. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:405-19. [PMID: 26512058 PMCID: PMC4682442 DOI: 10.1093/jxb/erv476] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na(+)/K(+) ratios in shoots, and Na(+) translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots. Exogenous ABA was able to enhance the salt tolerance of IR64 by selectively decreasing accumulation of Na(+) in its roots and increasing K(+) in its shoots. Salt stress induced general and organ-specific increases of many primary metabolites in both rice genotypes, with strong accumulation of several sugars plus proline in shoots and allantoin in roots. This was due primarily to ABA-mediated repression of genes for degradation of these metabolites under salt. In PL177, salt specifically up-regulated genes involved in several pathways underlying salt tolerance, including ABA-mediated cellular lipid and fatty acid metabolic processes and cytoplasmic transport, sequestration by vacuoles, detoxification and cell-wall remodeling in shoots, and oxidation-reduction reactions in roots. Combined genetic and transcriptomic evidence shortlisted relatively few candidate genes for improved salt tolerance in PL177.
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Affiliation(s)
- Wen-Sheng Wang
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Xiu-Qin Zhao
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Min Li
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China School of Science, Anhui Agricultural University, Hefei 230036, PR China
| | - Li-Yu Huang
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Jian-Long Xu
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen 518120, PR China
| | - Fan Zhang
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Yan-Ru Cui
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Bin-Ying Fu
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen 518120, PR China
| | - Zhi-Kang Li
- Institute of Crop Sciences/National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China Shenzhen Institute of Breeding and Innovation, Chinese Academy of Agricultural Sciences, Shenzhen 518120, PR China
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217
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Wang L, Wu X, Liu Y, Qiu QS. AtNHX5 and AtNHX6 Control Cellular K+ and pH Homeostasis in Arabidopsis: Three Conserved Acidic Residues Are Essential for K+ Transport. PLoS One 2015; 10:e0144716. [PMID: 26650539 PMCID: PMC4674129 DOI: 10.1371/journal.pone.0144716] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Accepted: 11/23/2015] [Indexed: 11/22/2022] Open
Abstract
AtNHX5 and AtNHX6, the endosomal Na+,K+/H+ antiporters in Arabidopsis, play an important role in plant growth and development. However, their function in K+ and pH homeostasis remains unclear. In this report, we characterized the function of AtNHX5 and AtNHX6 in K+ and H+ homeostasis in Arabidopsis. Using a yeast expression system, we found that AtNHX5 and AtNHX6 recovered tolerance to high K+ or salt. We further found that AtNHX5 and AtNHX6 functioned at high K+ at acidic pH while AtCHXs at low K+ under alkaline conditions. In addition, we showed that the nhx5 nhx6 double mutant contained less K+ and was sensitive to low K+ treatment. Overexpression of AtNHX5 or AtNHX6 gene in nhx5 nhx6 recovered root growth to the wild-type level. Three conserved acidic residues, D164, E188, and D193 in AtNHX5 and D165, E189, and D194 in AtNHX6, were essential for K+ homeostasis and plant growth. nhx5 nhx6 had a reduced vacuolar and cellular pH as measured with the fluorescent pH indicator BCECF or semimicroelectrode. We further show that AtNHX5 and AtNHX6 are localized to Golgi and TGN. Taken together, AtNHX5 and AtNHX6 play an important role in K+ and pH homeostasis in Arabidopsis. Three conserved acidic residues are essential for K+ transport.
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Affiliation(s)
- Liguang Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| | - Xuexia Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| | - Yafen Liu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China, 73000
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218
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Wu H, Shabala L, Zhou M, Stefano G, Pandolfi C, Mancuso S, Shabala S. Developing and validating a high-throughput assay for salinity tissue tolerance in wheat and barley. PLANTA 2015; 242:847-57. [PMID: 25991439 DOI: 10.1007/s00425-015-2317-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Accepted: 04/29/2015] [Indexed: 05/07/2023]
Abstract
Leaf tissue tolerance was strongly and positively correlated with overall salt tolerance in barley, but not in wheat where the inability of sensitive varieties to exclude Na(+) is compensated by their better ability to handle Na(+) accumulated in the shoot via tissue tolerance mechanisms. A new high-throughput assay was developed to use the excised leaves to eliminate the confounding contribution of sodium exclusion mechanisms and evaluate genetic variability in salinity tissue tolerance in a large number of wheat (Triticum aestivum and Triticum turgidum ssp. durum) and barley (Hordeum vulgare) accessions. The changes in relative chlorophyll content (measured as chlorophyll content index, CCI) in excised leaves exposed to 50 mM NaCl for 48 h were found to be a reliable indicator of leaf tissue tolerance. In both wheat and barley, relative CCI correlated strongly with the overall plant salinity tolerance (evaluated in glasshouse experiments). To a large extent, this tissue tolerance was related to more efficient vacuolar Na(+) sequestration in leaf mesophyll, as revealed by fluorescent Na(+) dye imaging experiments. However, while in barley this correlation was positive, tissue tolerance in wheat correlated negatively with overall salinity tolerance. As a result, more salt-sensitive durum wheat genotypes possessed higher tissue tolerance than bread wheat plants, and this negative correlation was present within each of bread and durum wheat clusters as well. Overall, these results indicate that the lack of effective Na(+) exclusion ability in sensitive wheat varieties is compensated by their better ability to handle Na(+) accumulated in the shoot via tissue tolerance mechanisms. Implications of these findings for plant breeding for salinity tolerance are discussed.
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Affiliation(s)
- Honghong Wu
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, TAS, 7001, Australia
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219
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Gouiaa S, Khoudi H. Co-expression of vacuolar Na(+)/H(+) antiporter and H(+)-pyrophosphatase with an IRES-mediated dicistronic vector improves salinity tolerance and enhances potassium biofortification of tomato. PHYTOCHEMISTRY 2015; 117:537-546. [PMID: 26047526 DOI: 10.1016/j.phytochem.2015.05.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 05/18/2015] [Accepted: 05/26/2015] [Indexed: 06/04/2023]
Abstract
Potassium (K) deficiency is a worldwide problem. Thus, the K biofortification of crops is needed to enhance human nutrition. Tomato represents an ideal candidate for such biofortification programs thanks to its widespread distribution and its easy growth on a commercial scale. However, although tomato is moderately tolerant to abiotic stresses, the crop losses due to salinity can be severe. In this study, we generated transgenic tomato plants over-expressing a Na(+)-K(+)/H(+) exchanger gene (TNHXS1), singly or with H(+)-pyrophosphatase (H(+)-PPiase) gene using a bicistronic construct. Transgenic tomato lines co-expressing both genes (LNV) significantly showed higher salinity tolerance than the wild-type (WT) plans or those expressing the TNHXS1 gene alone (LN). Indeed, under salt stress conditions, double transgenic plants produced higher biomass and retained more chlorophyll and catalase (CAT) activity. In addition, they showed earlier flowering and produced more fruits. To address K deficiencies in humans, an increase of 50% in K content of vegetable products was proposed. In this study, ion content analysis revealed that, under salt stress, fruits from double transgenic plants accumulated 5 times more potassium and 9 times less sodium than WT counterparts. Interestingly, the ionomic analysis of tomato fruits also revealed that LNV had a distinct profile compared to WT and to LN plants. Indeed, LNV fruits accumulated less Fe(2+), Ca(2+), Mg(2+) and Zn(2+), but more Mn(2+). This study demonstrates the effectiveness of bicistronic constructs as an important tool for the enhancement of biofortification and salt stress tolerance in crops.
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Affiliation(s)
- Sandra Gouiaa
- Laboratory of Plant Protection and Improvement, Center of Biotechnology of Sfax (CBS), Route Sidi Mansour Km 6, B.P'1177', 3018 Sfax, Tunisia
| | - Habib Khoudi
- Laboratory of Plant Protection and Improvement, Center of Biotechnology of Sfax (CBS), Route Sidi Mansour Km 6, B.P'1177', 3018 Sfax, Tunisia.
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220
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Julkowska MM, Testerink C. Tuning plant signaling and growth to survive salt. TRENDS IN PLANT SCIENCE 2015; 20:586-594. [PMID: 26205171 DOI: 10.1016/j.tplants.2015.06.008] [Citation(s) in RCA: 234] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 06/16/2015] [Accepted: 06/25/2015] [Indexed: 05/20/2023]
Abstract
Salinity is one of the major abiotic factors threatening food security worldwide. Recently, our understanding of early processes underlying salinity tolerance has expanded. In this review, early signaling events, such as phospholipid signaling, calcium ion (Ca(2+)) responses, and reactive oxygen species (ROS) production, together with salt stress-induced abscisic acid (ABA) accumulation, are brought into the context of long-term salt stress-specific responses and alteration of plant growth. Salt-induced quiescent and recovery growth phases rely on modification of cell cycle activity, cell expansion, and cell wall extensibility. The period of initial growth arrest varies among different organs, leading to altered plant morphology. Studying stress-induced changes in growth dynamics can be used for screening to discover novel genes contributing to salt stress tolerance in model species and crops.
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Affiliation(s)
- Magdalena M Julkowska
- Section of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands
| | - Christa Testerink
- Section of Plant Physiology, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Science Park 904, 1098XH Amsterdam, The Netherlands.
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221
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Wu GQ, Feng RJ, Wang SM, Wang CM, Bao AK, Wei L, Yuan HJ. Co-expression of xerophyte Zygophyllum xanthoxylum ZxNHX and ZxVP1-1 confers enhanced salinity tolerance in chimeric sugar beet (Beta vulgaris L.). FRONTIERS IN PLANT SCIENCE 2015; 6:581. [PMID: 26284097 PMCID: PMC4517593 DOI: 10.3389/fpls.2015.00581] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 07/13/2015] [Indexed: 05/20/2023]
Abstract
Salinity is one of the major abiotic stresses that limit the growth and productivity of sugar beet (Beta vulgaris L.). To improve sugar beet's salinity tolerance, the ZxNHX and ZxVP1-1 genes encoding tonoplast Na(+)/H(+) antiporter and H(+)-PPase from xerophyte Zygophyllum xanthoxylum were co-expressed by Agrobacterium tumefaciens-mediated transformation. It is showed here that co-expression of ZxNHX and ZxVP1-1 confers enhanced salinity tolerance to the transformed sugar beet plants compared with the wild-type (WT) plants. The chimeric plants grew well in the presence of high salinity (400 mM NaCl), whereas WT plants displayed chlorosis and died within 8 days. Compared to WT plants, the chimeric plants co-expressing ZxNHX and ZxVP1-1 accumulated more proline, Na(+) and K(+) in their leaves and petioles when exposed to high salinity, which caused lower solute potential, retained more water and thus subjected to lesser cell membrane damage. Interestingly, the chimeric plants accumulated higher sucrose, glucose and fructose contents in their storage roots than WT plants in the absence or presence of high salinity. Our results suggested that co-expression of ZxNHX and ZxVP1-1 improved the osmoregulatory capacity in chimeric sugar beet through increased compartmentalization of ions into the vacuoles by enhancing the activity of proton pumps and thus mitigated Na(+)-toxicity for plants.
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Affiliation(s)
- Guo-Qiang Wu
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Rui-Jun Feng
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
| | - Suo-Min Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Chun-Mei Wang
- Lanzhou Institute of Husbandry and Pharmaceutical Science, Chinese Academy of Agricultural Sciences, Lanzhou, China
| | - Ai-Ke Bao
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Li Wei
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Hui-Jun Yuan
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou, China
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222
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Khan MS, Ahmad D, Khan MA. Trends in genetic engineering of plants with (Na+/H+) antiporters for salt stress tolerance. BIOTECHNOL BIOTEC EQ 2015. [DOI: 10.1080/13102818.2015.1060868] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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223
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Meng LS, Wang YB, Yao SQ, Liu A. Arabidopsis AINTEGUMENTA mediates salt tolerance by trans-repressing SCABP8. J Cell Sci 2015; 128:2919-27. [PMID: 26054800 DOI: 10.1242/jcs.172072] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 06/01/2015] [Indexed: 01/29/2023] Open
Abstract
The Arabidopsis AINTEGUMENTA (ANT) gene, which encodes an APETALA2 (AP2)-like transcription factor, controls plant organ cell number and organ size throughout shoot development. ANT is thus a key factor in the development of plant shoots. Here, we have found that ANT plays an essential role in conferring salt tolerance in Arabidopsis. ant-knockout mutants presented a salt-tolerant phenotype, whereas transgenic plants expressing ANT under the 35S promoter (35S:ANT) exhibited more sensitive phenotypes under high salt stress. Further analysis indicated that ANT functions mainly in the shoot response to salt toxicity. Target gene analysis revealed that ANT bound to the promoter of SOS3-LIKE CALCIUM BINDING PROTEIN 8 (SCABP8), which encodes a putative Ca(2+) sensor, thereby inhibiting expression of SCABP8 (also known as CBL10). It has been reported that the salt sensitivity of scabp8 is more prominent in shoot tissues. Genetic experiments indicated that the mutation of SCABP8 suppresses the ant-knockout salt-tolerant phenotype, implying that ANT functions as a negative transcriptional regulator of SCABP8 upon salt stress. Taken together, the above results reveal that ANT is a novel regulator of salt stress and that ANT binds to the SCABP8 promoter, mediating salt tolerance.
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Affiliation(s)
- Lai-Sheng Meng
- School of Bioengineering and Biotechnology, Tianshui Normal University, Tianshui 741001, People's Republic of China Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, People's Republic of China Division of Molecular Life Sciences, Pohang University of Science and Technology, Hyoja-dong, Pohang, Kyungbuk 790-784, Republic of Korea
| | - Yi-Bo Wang
- School of Bioengineering and Biotechnology, Tianshui Normal University, Tianshui 741001, People's Republic of China
| | - Shun-Qiao Yao
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, People's Republic of China
| | - Aizhong Liu
- Key Laboratory of Economic Plants and Biotechnology, Kunming Institute of Botany, Chinese Academy of Sciences, 132 Lanhei Road, Kunming 650201, People's Republic of China
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Yang Y, Tang RJ, Li B, Wang HH, Jin YL, Jiang CM, Bao Y, Su HY, Zhao N, Ma XJ, Yang L, Chen SL, Cheng XH, Zhang HX. Overexpression of a Populus trichocarpa H+-pyrophosphatase gene PtVP1.1 confers salt tolerance on transgenic poplar. TREE PHYSIOLOGY 2015; 35:663-77. [PMID: 25877769 DOI: 10.1093/treephys/tpv027] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 03/08/2015] [Indexed: 05/20/2023]
Abstract
The Arabidopsis vacuolar H(+)-pyrophosphatase (AVP1) has been well studied and subsequently employed to improve salt and/or drought resistance in herbaceous plants. However, the exact function of H(+)-pyrophosphatase in woody plants still remains unknown. In this work, we cloned a homolog of type I H(+)-pyrophosphatase gene, designated as PtVP1.1, from Populus trichocarpa, and investigated its function in both Arabidopsis and poplar. The deduced translation product PtVP1.1 shares 89.74% identity with AVP1. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and quantitative real-time PCR analyses revealed a ubiquitous expression pattern of PtVP1.1 in various tissues, including roots, stems, leaves and shoot tips. Heterologous expression of PtVP1.1 rescued the retarded-root-growth phenotype of avp1, an Arabidopsis knock out mutant of AVP1, on low carbohydrate medium. Overexpression of PtVP1.1 in poplar (P. davidiana × P. bolleana) led to more vigorous growth of transgenic plants in the presence of 150 mM NaCl. Microsomal membrane vesicles derived from PtVP1.1 transgenic plants exhibited higher H(+)-pyrophosphatase hydrolytic activity than those from wild type (WT). Further studies indicated that the improved salt tolerance was associated with a decreased Na(+) and increased K(+) accumulation in the leaves of transgenic plants. Na(+) efflux and H(+) influx in the roots of transgenic plants were also significantly higher than those in the WT plants. All these results suggest that PtVP1.1 is a functional counterpart of AVP1 and can be genetically engineered for salt tolerance improvement in trees.
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Affiliation(s)
- Y Yang
- College of Agriculture, Ludong University, 186 Hongqizhong Road, Yantai, China 264025 National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
| | - R J Tang
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032 Present address: Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - B Li
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
| | - H H Wang
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
| | - Y L Jin
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
| | - C M Jiang
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
| | - Y Bao
- National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
| | - H Y Su
- College of Agriculture, Ludong University, 186 Hongqizhong Road, Yantai, China 264025
| | - N Zhao
- College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua-East Road, Beijing, China 100083
| | - X J Ma
- College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua-East Road, Beijing, China 100083
| | - L Yang
- College of Life Sciences, Nanjing University, 22 Hankou Road, Nanjing, China 210093
| | - S L Chen
- College of Biological Sciences and Technology, Beijing Forestry University, 35 Qinghua-East Road, Beijing, China 100083
| | - X H Cheng
- College of Agriculture, Ludong University, 186 Hongqizhong Road, Yantai, China 264025
| | - H X Zhang
- College of Agriculture, Ludong University, 186 Hongqizhong Road, Yantai, China 264025 National Key Laboratory of Plant Molecular Genetics, Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, China 200032
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225
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Vaid N, Pandey P, Srivastava VK, Tuteja N. Pea lectin receptor-like kinase functions in salinity adaptation without yield penalty, by alleviating osmotic and ionic stresses and upregulating stress-responsive genes. PLANT MOLECULAR BIOLOGY 2015; 88:193-206. [PMID: 25863480 DOI: 10.1007/s11103-015-0319-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Accepted: 04/04/2015] [Indexed: 05/29/2023]
Abstract
Lectin receptor-like kinases (LecRLKs) are members of RLK family composed of lectin-like extracellular recognition domain, transmembrane domain and cytoplasmic kinase domain. LecRLKs are plasma membrane proteins believed to be involved in signal transduction. However, most of the members of the protein family even in plants have not been functionally well characterized. Herein, we show that Pisum sativum LecRLK (PsLecRLK) localized in plasma membrane systems and/or other regions of the cell and its transcript upregulated under salinity stress. Overexpression of PsLecRLK in transgenic tobacco plants confers salinity stress tolerance by alleviating both the ionic as well the osmotic component of salinity stress. The transgenic plants show better tissue compartmentalization of Na(+) and higher ROS scavenging activity which probably results in lower membrane damage, improved growth and yield maintenance even under salinity stress. Also, expression of several genes involved in cellular homeostasis is perturbed by PsLecRLK overexpression. Alleviation of osmotic and ionic components of salinity stress along with reduced oxidative damage and upregulation of stress-responsive genes in transgenic plants under salinity stress conditions could be possible mechanism facilitating enhanced stress tolerance. This study presents PsLecRLK as a promising candidate for crop improvement and also opens up new avenue to investigate its signalling pathway.
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Affiliation(s)
- Neha Vaid
- Plant Molecular Biology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
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226
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Reguera M, Bassil E, Tajima H, Wimmer M, Chanoca A, Otegui MS, Paris N, Blumwald E. pH Regulation by NHX-Type Antiporters Is Required for Receptor-Mediated Protein Trafficking to the Vacuole in Arabidopsis. THE PLANT CELL 2015; 27:1200-17. [PMID: 25829439 PMCID: PMC4558692 DOI: 10.1105/tpc.114.135699] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 02/26/2015] [Accepted: 03/12/2015] [Indexed: 05/18/2023]
Abstract
Protein trafficking requires proper ion and pH homeostasis of the endomembrane system. The NHX-type Na(+)/H(+) antiporters NHX5 and NHX6 localize to the Golgi, trans-Golgi network, and prevacuolar compartments and are required for growth and trafficking to the vacuole. In the nhx5 nhx6 T-DNA insertional knockouts, the precursors of the 2S albumin and 12S globulin storage proteins accumulated and were missorted to the apoplast. Immunoelectron microscopy revealed the presence of vesicle clusters containing storage protein precursors and vacuolar sorting receptors (VSRs). Isolation and identification of complexes of VSRs with unprocessed 12S globulin by 2D blue-native PAGE/SDS-PAGE indicated that the nhx5 nhx6 knockouts showed compromised receptor-cargo association. In vivo interaction studies using bimolecular fluorescence complementation between VSR2;1, aleurain, and 12S globulin suggested that nhx5 nhx6 knockouts showed a significant reduction of VSR binding to both cargoes. In vivo pH measurements indicated that the lumens of VSR compartments containing aleurain, as well as the trans-Golgi network and prevacuolar compartments, were significantly more acidic in nhx5 nhx6 knockouts. This work demonstrates the importance of NHX5 and NHX6 in maintaining endomembrane luminal pH and supports the notion that proper vacuolar trafficking and proteolytic processing of storage proteins require endomembrane pH homeostasis.
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Affiliation(s)
- Maria Reguera
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Elias Bassil
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Hiromi Tajima
- Department of Plant Sciences, University of California, Davis, California 95616
| | - Monika Wimmer
- Institute of Crop Science and Resource Conservation, Division of Plant Nutrition, University of Bonn, D-53115 Bonn, Germany
| | - Alexandra Chanoca
- Departments of Botany and Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Marisa S Otegui
- Departments of Botany and Genetics, University of Wisconsin, Madison, Wisconsin 53706
| | - Nadine Paris
- Biochemistry and Plant Molecular Biology Laboratory, Unité Mixte de Recherche 5004, 34060 Montpellier, France
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, California 95616
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227
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Zhang YM, Zhang HM, Liu ZH, Li HC, Guo XL, Li GL. The wheat NHX antiporter gene TaNHX2 confers salt tolerance in transgenic alfalfa by increasing the retention capacity of intracellular potassium. PLANT MOLECULAR BIOLOGY 2015; 87:317-27. [PMID: 25549607 DOI: 10.1007/s11103-014-0278-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 12/16/2014] [Indexed: 05/02/2023]
Abstract
Previous studies have shown that TaNHX2 transgenic alfalfa (Medicago sativa L.) accumulated more K(+) and less Na(+) in leaves than did the wild-type plants. To investigate whether the increased K(+) accumulation in transgenic plants is attributed to TaNHX2 gene expression and whether the compartmentalization of Na(+) into vacuoles or the intracellular compartmentalization of potassium is the critical mechanism for TaNHX2-dependent salt tolerance in transgenic alfalfa, aerated hydroponic culture was performed under three different stress conditions: control condition (0.1 mM Na(+) and 6 mM K(+) inside culture solution), K(+)-sufficient salt stress (100 mM NaCl and 6 mM K(+)) and K(+)-insufficient salt stress (100 mM NaCl and 0.1 mM K(+)). The transgenic alfalfa plants had lower K(+) efflux through specific K(+) channels and higher K(+) absorption through high-affinity K(+) transporters than did the wild-type plants. Therefore, the transgenic plants had greater K(+) contents and [K(+)]/[Na(+)] ratios in leaf tissue and cell sap. The intracellular compartmentalization of potassium is critical for TaNHX2-induced salt tolerance in transgenic alfalfa.
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Affiliation(s)
- Yan-Min Zhang
- Institute of Genetics and Physiology, Hebei Academy of Agriculture and Forestry Sciences, Plant Genetic Engineering Center of Hebei Province, Shijiazhuang, 050051, China,
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228
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Mekawy AMM, Assaha DVM, Yahagi H, Tada Y, Ueda A, Saneoka H. Growth, physiological adaptation, and gene expression analysis of two Egyptian rice cultivars under salt stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 87:17-25. [PMID: 25532120 DOI: 10.1016/j.plaphy.2014.12.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 12/11/2014] [Indexed: 05/20/2023]
Abstract
Abiotic stressors, such as high salinity, greatly affect plant growth. In an attempt to explore the mechanisms underlying salinity tolerance, physiological parameters of two local Egyptian rice (Oryza sativa L.) cultivars, Sakha 102 and Egyptian Yasmine, were examined under 50 mM NaCl stress for 14 days. The results indicate that Egyptian Yasmine is relatively salt tolerant compared to Sakha 102, and this was evident in its higher dry mass production, lower leaf Na(+) levels, and enhanced water conservation under salt stress conditions. Moreover, Egyptian Yasmine exhibited lower Na(+)/K(+) ratios in all tissues examined under salinity stress. The ability to maintain such traits seemed to differ in the leaves and roots of Egyptian Yasmine, and the root K(+) content was much higher in Egyptian Yasmine than in Sakha 102. In order to understand the basis for these differences, we studied transcript levels of genes encoding Na(+) and K(+) transport proteins in different tissues. In response to salinity stress, Egyptian Yasmine showed induction of expression of some membrane transporter/channel genes that may contribute to Na(+) exclusion from the shoots (OsHKT1;5), limiting excess Na(+) entry into the roots (OsLti6b), K(+) uptake (OsAKT1), and reduced expression of a Na(+) transporter gene (OsHKT2;1). Therefore, the active regulation of genes related to Na(+) transport at the transcription level may be involved in salt tolerance mechanisms of Egyptian Yasmine, and these mechanisms offer the promise of improved salinity stress tolerance in local Egyptian rice genotypes.
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Affiliation(s)
- Ahmad Mohammad M Mekawy
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Dekoum V M Assaha
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Hiroyuki Yahagi
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Yuma Tada
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Akihiro Ueda
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan.
| | - Hirofumi Saneoka
- Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
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229
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Yuan HJ, Ma Q, Wu GQ, Wang P, Hu J, Wang SM. ZxNHX controls Na⁺ and K⁺ homeostasis at the whole-plant level in Zygophyllum xanthoxylum through feedback regulation of the expression of genes involved in their transport. ANNALS OF BOTANY 2015; 115:495-507. [PMID: 25252687 PMCID: PMC4332602 DOI: 10.1093/aob/mcu177] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 07/09/2014] [Indexed: 05/19/2023]
Abstract
BACKGROUND AND AIMS In order to cope with arid environments, the xerohalophyte Zygophyllum xanthoxylum efficiently compartmentalizes Na(+) into vacuoles, mediated by ZxNHX, and maintains stability of K(+) in its leaves. However, the function of ZxNHX in controlling Na(+) and K(+) homeostasis at the whole-plant level remains unclear. In this study, the role of ZxNHX in regulating the expression of genes involved in Na(+) and K(+) transport and spatial distribution was investigated. METHODS The role of ZxNHX in maintaining Na(+) and K(+) homeostasis in Z. xanthoxylum was studied using post-transcriptional gene silencing via Agrobacterium-mediated transformation. Transformed plants were grown with or without 50 mm NaCl, and expression levels and physiological parameters were measured. KEY RESULTS It was found that 50 mm NaCl induced a 620 % increase in transcripts of ZxSOS1 but only an 80 % increase in transcripts of ZxHKT1;1 in roots of wild-type (WT) plants. Consequently, the ability of ZxSOS1 to transport Na(+) exceeded that of ZxHKT1;1, and Na(+) was loaded into the xylem by ZxSOS1 and delivered to the shoots. However, in a ZxNHX-silenced line (L7), the capacity to sequester Na(+) into vacuoles of leaves was weakened, which in turn regulated long-distance Na(+) transport from roots to shoots. In roots of L7, NaCl (50 mm) increased transcripts of ZxSOS1 by only 10 %, whereas transcripts of ZxHKT1;1 increased by 53 %. Thus, in L7, the transport ability of ZxHKT1;1 for Na(+) outweighed that of ZxSOS1. Na(+) was unloaded from the xylem stream, consequently reducing Na(+) accumulation and relative distribution in leaves, but increasing the relative distribution of Na(+) in roots and the net selective transport capacity for K(+) over Na(+) from roots to shoots compared with the WT. Silencing of ZxNHX also triggered a downregulation of ZxAKT1 and ZxSKOR in roots, resulting in a significant decrease in K(+) accumulation in all the tissues in plants grown in 50 mm NaCl. These changes led to a significant reduction in osmotic adjustment, and thus an inhibition of growth in ZxNHX-silenced lines. CONCLUSIONS The results suggest that ZxNHX is essential for controlling Na(+), K(+) uptake, long-distance transport and their homeostasis at whole-plant level via feedback regulation of the expression of genes involved in Na(+), K(+) transport. The net result is the maintenance of the characteristic salt accumulation observed in Z. xanthoxylum and the regulation of its normal growth. A model is proposed for the role of ZxNHX in regulating the Na(+) transport system in Z. xanthoxylum under saline conditions.
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Affiliation(s)
- Hui-Jun Yuan
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China
| | - Qing Ma
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China
| | - Guo-Qiang Wu
- School of Life Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, PR China
| | - Pei Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China
| | - Jing Hu
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China
| | - Suo-Min Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou 730020, PR China
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Wang ZY, Gehring C, Zhu J, Li FM, Zhu JK, Xiong L. The Arabidopsis Vacuolar Sorting Receptor1 is required for osmotic stress-induced abscisic acid biosynthesis. PLANT PHYSIOLOGY 2015; 167:137-52. [PMID: 25416474 PMCID: PMC4281004 DOI: 10.1104/pp.114.249268] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Osmotic stress activates the biosynthesis of the phytohormone abscisic acid (ABA) through a pathway that is rate limited by the carotenoid cleavage enzyme 9-cis-epoxycarotenoid dioxygenase (NCED). To understand the signal transduction mechanism underlying the activation of ABA biosynthesis, we performed a forward genetic screen to isolate mutants defective in osmotic stress regulation of the NCED3 gene. Here, we identified the Arabidopsis (Arabidopsis thaliana) Vacuolar Sorting Receptor1 (VSR1) as a unique regulator of ABA biosynthesis. The vsr1 mutant not only shows increased sensitivity to osmotic stress, but also is defective in the feedback regulation of ABA biosynthesis by ABA. Further analysis revealed that vacuolar trafficking mediated by VSR1 is required for osmotic stress-responsive ABA biosynthesis and osmotic stress tolerance. Moreover, under osmotic stress conditions, the membrane potential, calcium flux, and vacuolar pH changes in the vsr1 mutant differ from those in the wild type. Given that manipulation of the intracellular pH is sufficient to modulate the expression of ABA biosynthesis genes, including NCED3, and ABA accumulation, we propose that intracellular pH changes caused by osmotic stress may play a signaling role in regulating ABA biosynthesis and that this regulation is dependent on functional VSR1.
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Affiliation(s)
- Zhen-Yu Wang
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia (Z.-Y.W., C.G., L.X.);State Key Laboratory of Grassland Agroecosystem, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China (Z.-Y.W., F.-M.L.);Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 (J.Z.);Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); andShanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China (J.-K.Z.)
| | - Chris Gehring
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia (Z.-Y.W., C.G., L.X.);State Key Laboratory of Grassland Agroecosystem, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China (Z.-Y.W., F.-M.L.);Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 (J.Z.);Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); andShanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China (J.-K.Z.)
| | - Jianhua Zhu
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia (Z.-Y.W., C.G., L.X.);State Key Laboratory of Grassland Agroecosystem, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China (Z.-Y.W., F.-M.L.);Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 (J.Z.);Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); andShanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China (J.-K.Z.)
| | - Feng-Min Li
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia (Z.-Y.W., C.G., L.X.);State Key Laboratory of Grassland Agroecosystem, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China (Z.-Y.W., F.-M.L.);Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 (J.Z.);Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); andShanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China (J.-K.Z.)
| | - Jian-Kang Zhu
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia (Z.-Y.W., C.G., L.X.);State Key Laboratory of Grassland Agroecosystem, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China (Z.-Y.W., F.-M.L.);Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 (J.Z.);Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); andShanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China (J.-K.Z.)
| | - Liming Xiong
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia (Z.-Y.W., C.G., L.X.);State Key Laboratory of Grassland Agroecosystem, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, Gansu Province, China (Z.-Y.W., F.-M.L.);Department of Plant Science and Landscape Architecture, University of Maryland, College Park, Maryland 20742 (J.Z.);Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, Indiana 47907 (J.-K.Z.); andShanghai Center for Plant Stress Biology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China (J.-K.Z.)
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Kizhakkedath P, Jegadeeson V, Venkataraman G, Parida A. A vacuolar antiporter is differentially regulated in leaves and roots of the halophytic wild rice Porteresia coarctata (Roxb.) Tateoka. Mol Biol Rep 2014; 42:1091-105. [PMID: 25481774 DOI: 10.1007/s11033-014-3848-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 11/25/2014] [Indexed: 12/28/2022]
Abstract
Vacuolar NHX-type antiporters play a role in Na(+)/K(+) uptake that contributes to growth, nutrition and development. Under salt/osmotic stress they mediate the vacuolar compartmentalization of K(+)/Na(+), thereby preventing toxic Na(+)K(+) ratios in the cytosol. Porteresia coarctata (Roxb.) Tateoka, a mangrove associate, is a distant wild relative of cultivated rice and is saline as well as submergence tolerant. A vacuolar NHX homolog isolated from a P. coarctata cDNA library (PcNHX1) shows 96 % identity (nucleotide level) to OsNHX1. Diurnal PcNHX1 expression in leaves was found to be largely unaltered, though damped by salinity. PcNHX1 promoter directed GUS expression is phloem-specific in leaves, stem and roots of transgenic plants in the absence of stress. Under NaCl stress, GUS expression was also seen in the epidermal and sub-epidermal layers (mesophyll, guard cells and trichomes) of leaves, root tip. The salinity in the rhizosphere of P. coarctata varies considerably due to diurnal/semi-diurnal tidal inundation. The diurnal expression of PcNHX1 in leaves and salinity induced expression in roots may have evolved in response to dynamic changes in salinity of in the P. coarctata rhizosphere. Despite high sequence conservation between OsNHX1 and PcNHX1, the distinctive expression pattern of PcNHX1 exemplifies how variation in expression is fine tuned to suit the halophytic growth habitat of a plant.
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Affiliation(s)
- Praseetha Kizhakkedath
- Department of Plant Molecular Biology, M.S. Swaminathan Research Foundation, III Cross Street, Taramani Institutional Area, Chennai, 600113, India
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232
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Bassil E, Blumwald E. The ins and outs of intracellular ion homeostasis: NHX-type cation/H(+) transporters. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:1-6. [PMID: 25173972 DOI: 10.1016/j.pbi.2014.08.002] [Citation(s) in RCA: 115] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/14/2014] [Accepted: 08/14/2014] [Indexed: 05/18/2023]
Abstract
The biochemical characterization of cation/H(+) exchange has been known since 1985 [1], yet only recently have we begun to understand the contribution of individual exchangers to ion homeostasis in plants. One particularly important class of exchangers is the NHX-type that is associated with Na(+) transport and therefore salinity tolerance. New evidence suggests that under normal growth conditions NHXs are critical regulators of K(+) and pH homeostasis and have important roles, depending on their cellular localization, in the generation of turgor as well as in vesicular trafficking. Recent advances highlight novel and exciting functions of intracellular NHXs in growth and development, stress adaptation and osmotic adjustment. Here, we elaborate on new and emerging cellular and physiological functions of this group of H(+)-coupled cation exchangers.
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Affiliation(s)
- Elias Bassil
- Department of Plant Sciences, University of California, Davis, CA 95616, United States
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, CA 95616, United States.
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233
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Schumacher K. pH in the plant endomembrane system-an import and export business. CURRENT OPINION IN PLANT BIOLOGY 2014; 22:71-76. [PMID: 25282587 DOI: 10.1016/j.pbi.2014.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 09/11/2014] [Accepted: 09/12/2014] [Indexed: 05/06/2023]
Abstract
pH homeostasis is an essential process in all plant cells and the maintenance of correct luminal pH in the compartments of the endomembrane system is important not only for secondary active transport but also for a variety of cellular functions including protein modification, sorting, and trafficking. Due to their electrogenicity primary H(+)-pumps cannot establish and control the often large proton-gradients single-handedly but require the co-action of other ion transporters that serve as either shunt conductances or proton-leaks. Here, I will thus focus on recent results that highlight the interplay of proton-pumps and proton-coupled transporters in controlling pH in the compartments of the plant endomembrane system.
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Affiliation(s)
- Karin Schumacher
- Dep. of Cell Biology, Centre for Organismal Studies (COS), Universität Heidelberg, 69120 Heidelberg, Germany.
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234
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Remy E, Cabrito TR, Batista RA, Teixeira MC, Sá-Correia I, Duque P. The Major Facilitator Superfamily Transporter ZIFL2 Modulates Cesium and Potassium Homeostasis in Arabidopsis. ACTA ACUST UNITED AC 2014; 56:148-62. [DOI: 10.1093/pcp/pcu157] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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235
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Chen X, Bao H, Guo J, Jia W, Tai F, Nie L, Jiang P, Feng J, Lv S, Li Y. Na⁺/H⁺ exchanger 1 participates in tobacco disease defence against Phytophthora parasitica var. nicotianae by affecting vacuolar pH and priming the antioxidative system. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:6107-22. [PMID: 25170102 PMCID: PMC4203143 DOI: 10.1093/jxb/eru351] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Despite the importance of NHX1 (Na(+)/H(+) exchanger 1) in plant salt tolerance, little is known about its other functions. In this study, intriguingly, it was found that NHX1 participated in plant disease defence against Phytophthora parasitica var. nicotianae (Ppn) in Nicotiana benthamiana. NbNHX1 was originally isolated from N. benthamiana, and characterized. The subcellular localization of NbNHX1 with its C-terminus fused with green fluorescent protein indicated that NbNHX1 localized primarily to the tonoplast. Tobacco rattle virus-induced NbNHX1 silencing led to reduced H(+) efflux from the vacuole to cytoplasts, and decreased Ppn resistance in N. benthamiana. After attack by Ppn, NbNHX1-silenced plants exhibited impaired ability to scavenge reactive oxidative species (ROS) induced by the pathogen. Pea early browning virus-mediated ectopic expression of SeNHX1 (from Salicornia europaea) or AtNHX1 (from Arabidopsis thaliana) both conferred enhanced Ppn resistance to N. benthamiana, with a lower H2O2 concentration after Ppn inoculation. Further investigation of the role of NHX1 demonstrated that transient overexpression of NbNHX1 improved the vacuolar pH and cellular ROS level in N. benthamiana, which was coupled with an enlarged NAD(P) (H) pool and higher expression of ROS-responsive genes. In contrast, NbNHX1 silencing led to a lower pH in the vacuole and a lower cellular ROS level in N. benthamiana, which was coupled with a decreased NAD(P) (H) pool and decreased expression of ROS-responsive genes. These results suggest that NHX1 is involved in plant disease defence; and regulation of vacuolar pH by NHX1, affecting the cellular oxidation state, primes the antioxidative system which is associated with Ppn resistance in tobacco.
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Affiliation(s)
- Xianyang Chen
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Hexigeduleng Bao
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Jie Guo
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Weitao Jia
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Fang Tai
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Lingling Nie
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Ping Jiang
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Juanjuan Feng
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Sulian Lv
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
| | - Yinxin Li
- Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, PR China
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236
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Beauzamy L, Nakayama N, Boudaoud A. Flowers under pressure: ins and outs of turgor regulation in development. ANNALS OF BOTANY 2014; 114:1517-33. [PMID: 25288632 PMCID: PMC4204789 DOI: 10.1093/aob/mcu187] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 08/01/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Turgor pressure is an essential feature of plants; however, whereas its physiological importance is unequivocally recognized, its relevance to development is often reduced to a role in cell elongation. SCOPE This review surveys the roles of turgor in development, the molecular mechanisms of turgor regulation and the methods used to measure turgor and related quantities, while also covering the basic concepts associated with water potential and water flow in plants. Three key processes in flower development are then considered more specifically: flower opening, anther dehiscence and pollen tube growth. CONCLUSIONS Many molecular determinants of turgor and its regulation have been characterized, while a number of methods are now available to quantify water potential, turgor and hydraulic conductivity. Data on flower opening, anther dehiscence and lateral root emergence suggest that turgor needs to be finely tuned during development, both spatially and temporally. It is anticipated that a combination of biological experiments and physical measurements will reinforce the existing data and reveal unexpected roles of turgor in development.
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Affiliation(s)
- Léna Beauzamy
- Reproduction et Développement des Plantes, INRA, CNRS, ENS de Lyon, UCBL Lyon I, 46 Allée d'Italie, 69364 Lyon Cedex 07, France Laboratoire Joliot-Curie, CNRS, ENS de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
| | - Naomi Nakayama
- Reproduction et Développement des Plantes, INRA, CNRS, ENS de Lyon, UCBL Lyon I, 46 Allée d'Italie, 69364 Lyon Cedex 07, France Laboratoire Joliot-Curie, CNRS, ENS de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France Institute of Molecular Plant Sciences, University of Edinburgh, Mayfield Rd, King's Buildings, Edinburgh EH9 3JH, UK
| | - Arezki Boudaoud
- Reproduction et Développement des Plantes, INRA, CNRS, ENS de Lyon, UCBL Lyon I, 46 Allée d'Italie, 69364 Lyon Cedex 07, France Laboratoire Joliot-Curie, CNRS, ENS de Lyon, 46 Allée d'Italie, 69364 Lyon Cedex 07, France
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237
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Gong X, Zhang J, Liu JH. A stress responsive gene of Fortunella crassifolia FcSISP functions in salt stress resistance. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2014; 83:10-9. [PMID: 25054478 DOI: 10.1016/j.plaphy.2014.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 07/03/2014] [Indexed: 05/23/2023]
Abstract
Exploration of genes functioning in salt tolerance is crucial for generating transgenic plants with enhanced salt tolerance. In this study, we report the isolation and functional characterization of a stress-responsive gene FcSISP from Meiwa kumquat (Fortunella crassifolia). FcSISP encodes a putative protein of 47 amino acids, with a calculated molecular mass of 4.94 kDa and theoretical isoelectric point of 3.76, and was localized in the nucleus. Transcript levels of FcSISP were induced by dehydration, cold, salt and bacterium causing citrus canker, and hormones (salicylic acid and abscisic acid), with the greatest induction under salt treatment. Overexpression of FcSISP in tobacco (Nicotiana nudicaulis) conferred enhanced salt tolerance. The transgenic lines accumulated lower Na(+) contents, leading to reduced Na/K ratio, but accumulated more proline than the wild type (WT). Steady state mRNA levels of genes involved in Na(+) exchange (three SOS genes and three NHX genes) and proline synthesis (P5CS and P5CR) were higher in the transgenic lines in comparison with WT. Moreover, overexpression of FcSISP in trifoliate orange [Poncirus trifoliata (L.) Raf.], a widely-used and salt-sensitive citrus rootstock, led to elevated salt tolerance. Taken together, the data demonstrate that FcSISP plays a positive role in salt tolerance and that it holds a great potential for engineering salt tolerance in crops.
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Affiliation(s)
- Xiaoqing Gong
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Jingyan Zhang
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Ji-Hong Liu
- Key Laboratory of Horticultural Plant Biology (MOE), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan 430070, China.
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238
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McCubbin T, Bassil E, Zhang S, Blumwald E. Vacuolar Na⁺/H⁺ NHX-Type Antiporters Are Required for Cellular K⁺ Homeostasis, Microtubule Organization and Directional Root Growth. PLANTS 2014; 3:409-26. [PMID: 27135511 PMCID: PMC4844347 DOI: 10.3390/plants3030409] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/07/2014] [Accepted: 08/18/2014] [Indexed: 12/13/2022]
Abstract
Na⁺/H⁺ antiporters (NHXs) are integral membrane transporters that catalyze the electroneutral exchange of K⁺ or Na⁺ for H⁺ and are implicated in cell expansion, development, pH and ion homeostasis and salt tolerance. Arabidopsis contains four vacuolar NHX isoforms (NHX1-NHX4), but only the functional roles for NHX1 and NHX2 have been assessed thus far. Colocalization studies indicated that NHX3 and NHX4 colocalize to the tonoplast. To investigate the role of all vacuolar NHX isoforms, a quadruple knockout nhx1nhx2nhx3nhx4, lacking all vacuolar NHXs, was generated. Seedlings of nhx1nhx2nhx3nhx4 displayed significantly reduced growth, with markedly shorter hypocotyls. Under high K⁺, but not Na⁺, pronounced root skewing occurred in nhx1nhx2nhx3nhx4, suggesting that the organization of the cytoskeleton might be perturbed. Whole mount immunolabeling of cortical microtubules indicated that high K⁺ caused significant microtubule reorganization in nhx1nhx2nhx3nhx4 root cells of the elongation zone. Using microtubule stabilizing (Taxol) and destabilizing (propyzamide) drugs, we found that the effect of K⁺ on nhx1nhx2nhx3nhx4 root growth was antagonistic to that of Taxol, whereas elevated K⁺ exacerbated the endogenous effect of propyzamide on root skewing. Collectively, our results suggest that altered K⁺ homeostasis leads to an increase in the dynamics of cortical microtubule reorganization in nhx1nhx2nhx3nhx4 root epidermal cells of the elongation zone.
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Affiliation(s)
- Tyler McCubbin
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| | - Elias Bassil
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| | - Shiqi Zhang
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
| | - Eduardo Blumwald
- Department of Plant Sciences, University of California, Davis, CA 95616, USA.
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239
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Wang L, Feng X, Zhao H, Wang L, An L, Qiu QS. Functional analysis of the Na+,K+/H+ antiporter PeNHX3 from the tree halophyte Populus euphratica in yeast by model-guided mutagenesis. PLoS One 2014; 9:e104147. [PMID: 25093858 PMCID: PMC4122410 DOI: 10.1371/journal.pone.0104147] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 07/08/2014] [Indexed: 01/08/2023] Open
Abstract
Na+,K+/H+ antiporters are H+-coupled cotransporters that are crucial for cellular homeostasis. Populus euphratica, a well-known tree halophyte, contains six Na+/H+ antiporter genes (PeNHX1-6) that have been shown to function in salt tolerance. However, the catalytic mechanisms governing their ion transport remain largely unknown. Using the crystal structure of the Na+/H+ antiporter from the Escherichia coli (EcNhaA) as a template, we built the three-dimensional structure of PeNHX3 from P. euphratica. The PeNHX3 model displays the typical TM4-TM11 assembly that is critical for ion binding and translocation. The PeNHX3 structure follows the 'positive-inside' rule and exhibits a typical physicochemical property of the transporter proteins. Four conserved residues, including Tyr149, Asn187, Asp188, and Arg356, are indentified in the TM4-TM11 assembly region of PeNHX3. Mutagenesis analysis showed that these reserved residues were essential for the function of PeNHX3: Asn187 and Asp188 (forming a ND motif) controlled ion binding and translocation, and Tyr149 and Arg356 compensated helix dipoles in the TM4-TM11 assembly. PeNHX3 mediated Na+, K+ and Li+ transport in a yeast growth assay. Domain-switch analysis shows that TM11 is crucial to Li+ transport. The novel features of PeNHX3 in ion binding and translocation are discussed.
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Affiliation(s)
- Liguang Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Xueying Feng
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Hong Zhao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Lidong Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Lizhe An
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
| | - Quan-Sheng Qiu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, China
- * E-mail:
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240
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Ismail A, Takeda S, Nick P. Life and death under salt stress: same players, different timing? JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:2963-79. [PMID: 24755280 DOI: 10.1093/jxb/eru159] [Citation(s) in RCA: 141] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Salinity does not only stress plants but also challenges human life and the economy by posing severe constraints upon agriculture. To understand salt adaptation strategies of plants, it is central to extend agricultural production to salt-affected soils. Despite high impact and intensive research, it has been difficult to dissect the plant responses to salt stress and to define the decisive key factors for the outcome of salinity signalling. To connect the rapidly accumulating data from different systems, treatments, and organization levels (whole-plant, cellular, and molecular), and to identify the appropriate correlations among them, a clear conceptual framework is required. Similar to other stress responses, the molecular nature of the signals evoked after the onset of salt stress seems to be general, as with that observed in response to many other stimuli, and should not be considered to confer specificity per se. The focus of the current review is therefore on the temporal patterns of signals conveyed by molecules such as Ca(2+), H(+), reactive oxygen species, abscisic acid, and jasmonate. We propose that the outcome of the salinity response (adaptation versus cell death) depends on the timing with which these signals appear and disappear. In this context, the often-neglected non-selective cation channels are relevant. We also propose that constraining a given signal is as important as its induction, as it is the temporal competence of signalling (signal on demand) that confers specificity.
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Affiliation(s)
- Ahmed Ismail
- Department of Horticulture, Faculty of Agriculture, Damanhour University, Damanhour, Egypt
| | - Shin Takeda
- Bioscience and Biotechnology Center, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Peter Nick
- Molecular Cell Biology, Botanical Institute, Karlsruhe Institute of Technology (KIT), Germany
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241
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Eisenach C, Baetz U, Martinoia E. Vacuolar proton pumping: more than the sum of its parts? TRENDS IN PLANT SCIENCE 2014; 19:344-6. [PMID: 24703550 DOI: 10.1016/j.tplants.2014.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/12/2014] [Accepted: 03/18/2014] [Indexed: 05/21/2023]
Abstract
Petunia flower colour is dependent on vacuolar pH and is therefore used to study acidification mechanisms. Recently, it was shown that the concerted action of two tonoplast-localised P3-ATPases is required to hyperacidify vacuoles of petunia petal epidermis cells. Here we discuss how steep cross-tonoplast pH gradients may be established in specific cells.
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Affiliation(s)
- Cornelia Eisenach
- Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland.
| | - Ulrike Baetz
- Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Enrico Martinoia
- Institute of Plant Biology, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
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242
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Jarvis DE, Ryu CH, Beilstein MA, Schumaker KS. Distinct Roles for SOS1 in the Convergent Evolution of Salt Tolerance in Eutrema salsugineum and Schrenkiella parvula. Mol Biol Evol 2014; 31:2094-107. [DOI: 10.1093/molbev/msu152] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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243
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Plastidial transporters KEA1, -2, and -3 are essential for chloroplast osmoregulation, integrity, and pH regulation in Arabidopsis. Proc Natl Acad Sci U S A 2014; 111:7480-5. [PMID: 24794527 DOI: 10.1073/pnas.1323899111] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Multiple K(+) transporters and channels and the corresponding mutants have been described and studied in the plasma membrane and organelle membranes of plant cells. However, knowledge about the molecular identity of chloroplast K(+) transporters is limited. Potassium transport and a well-balanced K(+) homeostasis were suggested to play important roles in chloroplast function. Because no loss-of-function mutants have been identified, the importance of K(+) transporters for chloroplast function and photosynthesis remains to be determined. Here, we report single and higher-order loss-of-function mutants in members of the cation/proton antiporters-2 antiporter superfamily KEA1, KEA2, and KEA3. KEA1 and KEA2 proteins are targeted to the inner envelope membrane of chloroplasts, whereas KEA3 is targeted to the thylakoid membrane. Higher-order but not single mutants showed increasingly impaired photosynthesis along with pale green leaves and severely stunted growth. The pH component of the proton motive force across the thylakoid membrane was significantly decreased in the kea1kea2 mutants, but increased in the kea3 mutant, indicating an altered chloroplast pH homeostasis. Electron microscopy of kea1kea2 leaf cells revealed dramatically swollen chloroplasts with disrupted envelope membranes and reduced thylakoid membrane density. Unexpectedly, exogenous NaCl application reversed the observed phenotypes. Furthermore, the kea1kea2 background enables genetic analyses of the functional significance of other chloroplast transporters as exemplified here in kea1kea2Na(+)/H(+) antiporter1 (nhd1) triple mutants. Taken together, the presented data demonstrate a fundamental role of inner envelope KEA1 and KEA2 and thylakoid KEA3 transporters in chloroplast osmoregulation, integrity, and ion and pH homeostasis.
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244
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Andrés Z, Pérez-Hormaeche J, Leidi EO, Schlücking K, Steinhorst L, McLachlan DH, Schumacher K, Hetherington AM, Kudla J, Cubero B, Pardo JM. Control of vacuolar dynamics and regulation of stomatal aperture by tonoplast potassium uptake. Proc Natl Acad Sci U S A 2014; 111:E1806-14. [PMID: 24733919 PMCID: PMC4035970 DOI: 10.1073/pnas.1320421111] [Citation(s) in RCA: 126] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Stomatal movements rely on alterations in guard cell turgor. This requires massive K(+) bidirectional fluxes across the plasma and tonoplast membranes. Surprisingly, given their physiological importance, the transporters mediating the energetically uphill transport of K(+) into the vacuole remain to be identified. Here, we report that, in Arabidopsis guard cells, the tonoplast-localized K(+)/H(+) exchangers NHX1 and NHX2 are pivotal in the vacuolar accumulation of K(+) and that nhx1 nhx2 mutant lines are dysfunctional in stomatal regulation. Hypomorphic and complete-loss-of-function double mutants exhibited significantly impaired stomatal opening and closure responses. Disruption of K(+) accumulation in guard cells correlated with more acidic vacuoles and the disappearance of the highly dynamic remodelling of vacuolar structure associated with stomatal movements. Our results show that guard cell vacuolar accumulation of K(+) is a requirement for stomatal opening and a critical component in the overall K(+) homeostasis essential for stomatal closure, and suggest that vacuolar K(+) fluxes are also of decisive importance in the regulation of vacuolar dynamics and luminal pH that underlie stomatal movements.
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Affiliation(s)
- Zaida Andrés
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Cientificas, 41012 Seville, Spain
| | - Javier Pérez-Hormaeche
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Cientificas, 41012 Seville, Spain
| | - Eduardo O. Leidi
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Cientificas, 41012 Seville, Spain
| | - Kathrin Schlücking
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, 48149 Münster, Germany
| | - Leonie Steinhorst
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, 48149 Münster, Germany
| | - Deirdre H. McLachlan
- School of Biological Sciences, University of Bristol, Bristol BS8 1UG, United Kingdom; and
| | - Karin Schumacher
- Centre for Organismal Studies, Universität Heidelberg, 69120 Heidelberg, Germany
| | | | - Jörg Kudla
- Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, 48149 Münster, Germany
| | - Beatriz Cubero
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Cientificas, 41012 Seville, Spain
| | - José M. Pardo
- Instituto de Recursos Naturales y Agrobiologia de Sevilla, Consejo Superior de Investigaciones Cientificas, 41012 Seville, Spain
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245
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Adem GD, Roy SJ, Zhou M, Bowman JP, Shabala S. Evaluating contribution of ionic, osmotic and oxidative stress components towards salinity tolerance in barley. BMC PLANT BIOLOGY 2014; 14:113. [PMID: 24774965 PMCID: PMC4021550 DOI: 10.1186/1471-2229-14-113] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 04/24/2014] [Indexed: 05/18/2023]
Abstract
BACKGROUND Salinity tolerance is a physiologically multi-faceted trait attributed to multiple mechanisms. Three barley (Hordeum vulgare) varieties contrasting in their salinity tolerance were used to assess the relative contribution of ionic, osmotic and oxidative stress components towards overall salinity stress tolerance in this species, both at the whole-plant and cellular levels. In addition, transcriptional changes in the gene expression profile were studied for key genes mediating plant ionic and oxidative homeostasis (NHX; RBOH; SOD; AHA and GORK), to compare a contribution of transcriptional and post-translational factors towards the specific components of salinity tolerance. RESULTS Our major findings are two-fold. First, plant tissue tolerance was a dominating component that has determined the overall plant responses to salinity, with root K(+) retention ability and reduced sensitivity to stress-induced hydroxyl radical production being the main contributing tolerance mechanisms. Second, it was not possible to infer which cultivars were salinity tolerant based solely on expression profiling of candidate genes at one specific time point. For the genes studied and the time point selected that transcriptional changes in the expression of these specific genes had a small role for barley's adaptive responses to salinity. CONCLUSIONS For better tissue tolerance, sodium sequestration, K(+) retention and resistance to oxidative stress all appeared to be crucial. Because these traits are highly interrelated, it is suggested that a major progress in crop breeding for salinity tolerance can be achieved only if these complementary traits are targeted at the same time. This study also highlights the essentiality of post translational modifications in plant adaptive responses to salinity.
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Affiliation(s)
- Getnet Dino Adem
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart Tas 7001, Australia
| | - Stuart J Roy
- Australian Centre for Plant Functional Genomics, Private Mail Bag 1, Glen Osmond SA 5064, Australia
- University of Adelaide, Private Mail Bag 1, Glen Osmond SA 5064, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart Tas 7001, Australia
| | - John P Bowman
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart Tas 7001, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart Tas 7001, Australia
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Kim CK, Lim HM, Na JK, Choi JW, Sohn SH, Park SC, Kim YH, Kim YK, Kim DY. A multistep screening method to identify genes using evolutionary transcriptome of plants. Evol Bioinform Online 2014; 10:69-78. [PMID: 24812480 PMCID: PMC3999899 DOI: 10.4137/ebo.s14823] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/25/2014] [Accepted: 03/28/2014] [Indexed: 11/17/2022] Open
Abstract
We introduced a multistep screening method to identify the genes in plants using microarrays and ribonucleic acid (RNA)-seq transcriptome data. Our method describes the process for identifying genes using the salt-tolerance response pathways of the potato (Solanum tuberosum) plant. Gene expression was analyzed using microarrays and RNA-seq experiments that examined three potato lines (high, intermediate, and low salt tolerance) under conditions of salt stress. We screened the orthologous genes and pathway genes involved in salinity-related biosynthetic pathways, and identified nine potato genes that were candidates for salinity-tolerance pathways. The nine genes were selected to characterize their phylogenetic reconstruction with homologous genes of Arabidopsis thaliana, and a Circos diagram was generated to understand the relationships among the selected genes. The involvement of the selected genes in salt-tolerance pathways was verified by reverse transcription polymerase chain reaction analysis. One candidate potato gene was selected for physiological validation by generating dehydration-responsive element-binding 1 (DREB1)-overexpressing transgenic potato plants. The DREB1 overexpression lines exhibited increased salt tolerance and plant growth when compared to that of the control. Although the nine genes identified by our multistep screening method require further characterization and validation, this study demonstrates the power of our screening strategy after the initial identification of genes using microarrays and RNA-seq experiments.
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Affiliation(s)
- Chang-Kug Kim
- Genomics Division, National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA), Suwon, Korea
| | - Hye-Min Lim
- Genomics Division, National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA), Suwon, Korea
| | - Jong-Kuk Na
- Molecular Breeding Division, NAAS, RDA, Suwon, Korea
| | - Ji-Weon Choi
- Vegetable Science Division, National Institute of Horticultural and Herbal Science, Suwon, Korea
| | - Seong-Han Sohn
- Genomics Division, National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA), Suwon, Korea
| | | | - Young-Hwan Kim
- Policy Development Office, Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries, Anyang, Korea
| | - Yong-Kab Kim
- School of Electrical Information Communication Engineering, Wonkwang University, Iksan, Korea
| | - Dool-Yi Kim
- Molecular Breeding Division, NAAS, RDA, Suwon, Korea
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247
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Roy SJ, Negrão S, Tester M. Salt resistant crop plants. Curr Opin Biotechnol 2014; 26:115-24. [DOI: 10.1016/j.copbio.2013.12.004] [Citation(s) in RCA: 674] [Impact Index Per Article: 67.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 12/27/2022]
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248
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Adams E, Shin R. Transport, signaling, and homeostasis of potassium and sodium in plants. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2014; 56:231-49. [PMID: 24393374 DOI: 10.1111/jipb.12159] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/31/2013] [Indexed: 05/17/2023]
Abstract
Potassium (K⁺) is an essential macronutrient in plants and a lack of K⁺ significantly reduces the potential for plant growth and development. By contrast, sodium (Na⁺), while beneficial to some extent, at high concentrations it disturbs and inhibits various physiological processes and plant growth. Due to their chemical similarities, some functions of K⁺ can be undertaken by Na⁺ but K⁺ homeostasis is severely affected by salt stress, on the other hand. Recent advances have highlighted the fascinating regulatory mechanisms of K⁺ and Na⁺ transport and signaling in plants. This review summarizes three major topics: (i) the transport mechanisms of K⁺ and Na⁺ from the soil to the shoot and to the cellular compartments; (ii) the mechanisms through which plants sense and respond to K⁺ and Na⁺ availability; and (iii) the components involved in maintenance of K⁺/Na⁺ homeostasis in plants under salt stress.
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Affiliation(s)
- Eri Adams
- RIKEN Center for Sustainable Resource Science, Yokohama, Kanagawa, 230-0045, Japan
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249
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Tang RJ, Yang Y, Yang L, Liu H, Wang CT, Yu MM, Gao XS, Zhang HX. Poplar calcineurin B-like proteins PtCBL10A and PtCBL10B regulate shoot salt tolerance through interaction with PtSOS2 in the vacuolar membrane. PLANT, CELL & ENVIRONMENT 2014; 37:573-88. [PMID: 23941462 DOI: 10.1111/pce.12178] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 07/19/2013] [Accepted: 07/26/2013] [Indexed: 05/20/2023]
Abstract
The calcineurin B-like protein (CBL) family represents a unique group of calcium sensors in plants. In Arabidopsis, CBL10 functions as a shoot-specific regulator in salt tolerance. We have identified two CBL10 homologs, PtCBL10A and PtCBL10B, from the poplar (Populus trichocarpa) genome. While PtCBL10A was ubiquitously expressed at low levels, PtCBL10B was preferentially expressed in the green-aerial tissues of poplar. Both PtCBL10A and PtCBL10B were targeted to the tonoplast and expression of either one in the Arabidopsis cbl10 mutant could rescue its shoot salt-sensitive phenotype. Like PtSOS3, both PtCBL10s physically interacted with the salt-tolerance component PtSOS2. But in contrast to the SOS3-SOS2 complex at the plasma membrane, the PtCBL10-SOS2 interaction was primarily associated with vacuolar compartments. Furthermore, overexpression of either PtCBL10A or PtCBL10B conferred salt tolerance on transgenic poplar plants by maintaining ion homeostasis in shoot tissues under salinity stress. These results not only suggest a crucial role of PtCBL10s in shoot responses to salt toxicity in poplar, but also provide a molecular basis for genetic engineering of salt-tolerant tree species.
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Affiliation(s)
- Ren-Jie Tang
- National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai, 200032, China
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250
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Reguera M, Bassil E, Blumwald E. Intracellular NHX-type cation/H+ antiporters in plants. MOLECULAR PLANT 2014; 7:261-3. [PMID: 23956073 DOI: 10.1093/mp/sst091] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Maria Reguera
- Department of Plant Sciences, Mail Stop 5, University of California, One Shields Ave, Davis, CA 95616, USA
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