51
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Su N, Wu Q, Chen J, Shabala L, Mithöfer A, Wang H, Qu M, Yu M, Cui J, Shabala S. GABA operates upstream of H+-ATPase and improves salinity tolerance in Arabidopsis by enabling cytosolic K+ retention and Na+ exclusion. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:6349-6361. [PMID: 31420662 PMCID: PMC6859739 DOI: 10.1093/jxb/erz367] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 08/02/2019] [Indexed: 05/19/2023]
Abstract
The non-protein amino acid γ-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to salinity. However, the physiological rationale for this elevation remains elusive. This study compared electrophysiological and whole-plant responses of salt-treated Arabidopsis mutants pop2-5 and gad1,2, which have different abilities to accumulate GABA. The pop2-5 mutant, which was able to overaccumulate GABA in its roots, showed a salt-tolerant phenotype. On the contrary, the gad1,2 mutant, lacking the ability to convert glutamate to GABA, showed oversensitivity to salinity. The greater salinity tolerance of the pop2-5 line was explained by: (i) the role of GABA in stress-induced activation of H+-ATPase, thus leading to better membrane potential maintenance and reduced stress-induced K+ leak from roots; (ii) reduced rates of net Na+ uptake; (iii) higher expression of SOS1 and NHX1 genes in the leaves, which contributed to reducing Na+ concentration in the cytoplasm by excluding Na+ to apoplast and sequestering Na+ in the vacuoles; (iv) a lower rate of H2O2 production and reduced reactive oxygen species-inducible K+ efflux from root epidermis; and (v) better K+ retention in the shoot associated with the lower expression level of GORK channels in plant leaves.
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Affiliation(s)
- Nana Su
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Qi Wu
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania 7001, Australia
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
| | - Jiahui Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lana Shabala
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Axel Mithöfer
- Research Group of Plant Defense Physiology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany
| | - Haiyang Wang
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Mei Qu
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Min Yu
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
| | - Jin Cui
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Sergey Shabala
- Tasmanian Institute for Agriculture, College of Science and Engineering, University of Tasmania, Hobart, Tasmania 7001, Australia
- International Research Centre for Environmental Membrane Biology, Foshan University, Foshan 528000, China
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González-Orenga S, Al Hassan M, Llinares JV, Lisón P, López-Gresa MP, Verdeguer M, Vicente O, Boscaiu M. Qualitative and Quantitative Differences in Osmolytes Accumulation and Antioxidant Activities in Response to Water Deficit in Four Mediterranean Limonium Species. PLANTS 2019; 8:plants8110506. [PMID: 31731597 PMCID: PMC6918351 DOI: 10.3390/plants8110506] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 12/27/2022]
Abstract
Limonium is a genus represented in the Iberian Peninsula by numerous halophytic species that are affected in nature by salinity, and often by prolonged drought episodes. Responses to water deficit have been studied in four Mediterranean Limonium species, previously investigated regarding salt tolerance mechanisms. The levels of biochemical markers, associated with specific responses—photosynthetic pigments, mono- and divalent ions, osmolytes, antioxidant compounds and enzymes—were determined in the control and water-stressed plants, and correlated with their relative degree of stress-induced growth inhibition. All the tested Limonium taxa are relatively resistant to drought on the basis of both the constitutive presence of high leaf ion levels that contribute to osmotic adjustment, and the stress-induced accumulation of osmolytes and increased activity of antioxidant enzymes, albeit with different qualitative and quantitative induction patterns. Limonium santapolense activated the strongest responses and clearly differed from Limonium virgatum, Limonium girardianum, and Limonium narbonense, as indicated by cluster and principal component analysis (PCA) analyses in agreement with its drier natural habitat, and compared to that of the other plants. Somewhat surprisingly, however, L. santapolense was the species most affected by water deficit in growth inhibition terms, which suggests the existence of additional mechanisms of defense operating in the field that cannot be mimicked in greenhouses.
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Affiliation(s)
- Sara González-Orenga
- Instituto Agroforestal Mediterráneo (IAM), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain; (S.G.-O.); (J.V.L.); (M.V.)
| | - Mohamad Al Hassan
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universitat Politècnica de València - Consejo Superior de Investigaciones Científicas (CSIC), Camino de Vera s/n, 46022 Valencia, Spain; (M.A.H.); (P.L.); (M.P.L.-G.)
- Wageningen UR Plant Breeding, Wageningen University and Research Centre, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Josep V. Llinares
- Instituto Agroforestal Mediterráneo (IAM), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain; (S.G.-O.); (J.V.L.); (M.V.)
| | - Purificación Lisón
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universitat Politècnica de València - Consejo Superior de Investigaciones Científicas (CSIC), Camino de Vera s/n, 46022 Valencia, Spain; (M.A.H.); (P.L.); (M.P.L.-G.)
| | - M. Pilar López-Gresa
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Universitat Politècnica de València - Consejo Superior de Investigaciones Científicas (CSIC), Camino de Vera s/n, 46022 Valencia, Spain; (M.A.H.); (P.L.); (M.P.L.-G.)
| | - Mercedes Verdeguer
- Instituto Agroforestal Mediterráneo (IAM), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain; (S.G.-O.); (J.V.L.); (M.V.)
| | - Oscar Vicente
- Instituto de Conservación y Mejora de la Agrodiversidad Valenciana (COMAV), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain;
| | - Monica Boscaiu
- Instituto Agroforestal Mediterráneo (IAM), Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain; (S.G.-O.); (J.V.L.); (M.V.)
- Correspondence: ; Tel.: +34-963-879-253; Fax: +34-963-879-269
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Chakraborty K, Chattaopadhyay K, Nayak L, Ray S, Yeasmin L, Jena P, Gupta S, Mohanty SK, Swain P, Sarkar RK. Ionic selectivity and coordinated transport of Na + and K + in flag leaves render differential salt tolerance in rice at the reproductive stage. PLANTA 2019; 250:1637-1653. [PMID: 31399792 DOI: 10.1007/s00425-019-03253-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 08/01/2019] [Indexed: 05/27/2023]
Abstract
The present study shows that salt tolerance in the reproductive stage of rice is primarily governed by the selective Na+ and K+ transport from the root to upper plant parts. Ionic discrimination at the flag leaf, governed by differential expression of Na+- and K+-specific transporters/ion pumps, is associated with reduced spikelet sterility and reproductive stage salt tolerance. Reproductive stage salt tolerance is crucial in rice to guarantee yield under saline condition. In the present study, differential ionic selectivity and the coordinated transport (from root to flag leaf) of Na+ and K+ were investigated to assess their impact on reproductive stage salt tolerance. Four rice genotypes having differential salt sensitivity were subjected to reproductive stage salinity stress in pots. The selective Na+ and K+ transport from the root to upper plant parts was observed in tolerant genotypes. We noticed that prolonged salt exposure did not alter flag leaf greenness even up to 6 weeks; however, it had a detrimental effect on panicle development especially in the salt-susceptible genotype Sabita. But more precise chlorophyll fluorescence imaging analysis revealed salinity-induced damages in Sabita. The salt-tolerant genotype Pokkali (AC41585), a potential Na+ excluder, managed to sequester higher Na+ load in the roots with little upward transport as evident from greater expression of HKT1 and HKT2 transporters. In contrast, the moderately salt-tolerant Lunidhan was less selective in Na+ transport, but possessed a higher capacity to Na+ sequestration in leaves. Higher K+ uptake and tissue-specific redistribution mediated by HAK and AKT transporters showed robust control in selective K+ movement from the root to flag leaf and developing panicles. On the contrary, expressions of Na+-specific transporters in developing panicles were either down-regulated or unaffected in tolerant and moderately tolerant genotypes. Yet, in the panicles of the susceptible genotype Sabita, some of the Na+-specific transporter genes (SOS1, HKT1;5, HKT2;4) were upregulated. Apart from the ionic regulation strategy, cellular energy balance mediated by different plasma-membrane and tonoplastic H+-pumps were also associated with the reproductive stage salt tolerance in rice.
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Affiliation(s)
| | | | - Lopamudra Nayak
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Soham Ray
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Lucina Yeasmin
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Priyanka Jena
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Sunanda Gupta
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Sangram K Mohanty
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Padmini Swain
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
| | - Ramani K Sarkar
- ICAR, National Rice Research Institute, Cuttack, Odisha, 753006, India
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54
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Gul M, Wakeel A, Steffens D, Lindberg S. Potassium-induced decrease in cytosolic Na + alleviates deleterious effects of salt stress on wheat (Triticum aestivum L.). PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:825-831. [PMID: 31034750 DOI: 10.1111/plb.12999] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 04/18/2019] [Indexed: 05/24/2023]
Abstract
Accumulation of NaCl in soil causes osmotic stress in plants, and sodium (Na+ ) and chloride (Cl- ) cause ion toxicity, but also reduce the potassium (K+ ) uptake by plant roots and stimulate the K+ efflux through the cell membrane. Thus, decreased K+ /Na+ ratio in plant tissue lead us to hypothesise that elevated levels of K+ in nutrient medium enhance this ratio in plant tissue and cytosol to improve enzyme activation, osmoregulation and charge balance. In this study, wheat was cultivated at different concentrations of K+ (2.2, 4.4 or 8.8 mm) with or without salinity (1, 60 or 120 mm NaCl) and the effects on growth, root and shoot Na+ and K+ distribution and grain yield were determined. Also, the cytosolic Na+ concentration was investigated, as well as photosynthesis rate and water potential. Salinity reduced fresh weight of both shoots and roots and dry weight of roots. The grain yield was significantly reduced under Na+ stress and improved with elevated K+ fertilisation. Elevated K+ level during cultivation prevented the accumulation of Na+ into the cytosol of both shoot and root protoplasts. Wheat growth at vegetative stage was transiently reduced at the highest K+ concentration, perhaps due to plants' efforts to overcome a high solute concentration in the plant tissue, nevertheless grain yield was increased at both K+ levels. In conclusion, a moderately elevated K+ application to wheat seedlings reduces tissue as well as cytosolic Na+ concentration and enhances wheat growth and grain yield by mitigating the deleterious effects of Na+ toxicity.
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Affiliation(s)
- M Gul
- Department of Soil Science, Bahauddin Zakariya University, Multan, Pakistan
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
- Department of Ecology, Environment and Plant Sciences, University of Stockholm, Stockholm, Sweden
| | - A Wakeel
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
| | - D Steffens
- Institute of Plant Nutrition, Interdisciplinary Research Center (IFZ), Justus Liebig University, Giessen, Germany
| | - S Lindberg
- Department of Ecology, Environment and Plant Sciences, University of Stockholm, Stockholm, Sweden
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55
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The Interplay among Polyamines and Nitrogen in Plant Stress Responses. PLANTS 2019; 8:plants8090315. [PMID: 31480342 PMCID: PMC6784213 DOI: 10.3390/plants8090315] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 08/27/2019] [Accepted: 08/28/2019] [Indexed: 12/27/2022]
Abstract
The interplay between polyamines (PAs) and nitrogen (N) is emerging as a key factor in plant response to abiotic and biotic stresses. The PA/N interplay in plants connects N metabolism, carbon (C) fixation, and secondary metabolism pathways. Glutamate, a pivotal N-containing molecule, is responsible for the biosynthesis of proline (Pro), arginine (Arg) and ornithine (Orn) and constitutes a main common pathway for PAs and C/N assimilation/incorporation implicated in various stresses. PAs and their derivatives are important signaling molecules, as they act largely by protecting and preserving the function/structure of cells in response to stresses. Use of different research approaches, such as generation of transgenic plants with modified intracellular N and PA homeostasis, has helped to elucidate a plethora of PA roles, underpinning their function as a major player in plant stress responses. In this context, a range of transgenic plants over-or under-expressing N/PA metabolic genes has been developed in an effort to decipher their implication in stress signaling. The current review describes how N and PAs regulate plant growth and facilitate crop acclimatization to adverse environments in an attempt to further elucidate the N-PAs interplay against abiotic and biotic stresses, as well as the mechanisms controlling N-PA genes/enzymes and metabolites.
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56
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Cai K, Gao H, Wu X, Zhang S, Han Z, Chen X, Zhang G, Zeng F. The Ability to Regulate Transmembrane Potassium Transport in Root Is Critical for Drought Tolerance in Barley. Int J Mol Sci 2019; 20:E4111. [PMID: 31443572 PMCID: PMC6747136 DOI: 10.3390/ijms20174111] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 08/11/2019] [Accepted: 08/20/2019] [Indexed: 01/26/2023] Open
Abstract
In this work, the effect of drought on K+ uptake in root and its translocation from root to shoot was investigated using six barley genotypes contrasting in drought tolerance. Results showed that drought conditions caused significant changes in K+ uptake and translocation in a time- and genotype-specific manner, which consequently resulted in a significant difference in tissue K+ contents and drought tolerance levels between the contrasting barley genotypes. The role of K+ transporters and channels and plasma membrane (PM) H+-ATPase in barley's adaptive response to drought stress was further investigated at the transcript level. The expression of genes conferring K+ uptake (HvHAK1, HvHAK5, HvKUP1, HvKUP2 and HvAKT1) and xylem loading (HvSKOR) in roots were all affected by drought stress in a time- and genotype-specific manner, indicating that the regulation of these K+ transporters and channels is critical for root K+ uptake and root to shoot K+ translocation in barley under drought stress. Furthermore, the barley genotypes showed a strong correlation between H+ efflux and K+ influx under drought stress, which was further confirmed by the significant up-regulation of HvHA1 and HvHA2. These results suggested an important role of plasma membrane H+-ATPase activity and/or expression in regulating the activity of K+ transporters and channels under drought stress. Taken together, it may be concluded that the genotypic difference in drought stress tolerance in barley is conferred by the difference in the ability to regulate K+ transporters and channels in root epidermis and stele.
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Affiliation(s)
- Kangfeng Cai
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Huaizhou Gao
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Xiaojian Wu
- Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
| | - Shuo Zhang
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Zhigang Han
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Xiaohui Chen
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Guoping Zhang
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China
| | - Fanrong Zeng
- Institute of Crop Science, Zhejiang University, Hangzhou 310058, China.
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57
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Vishwakarma K, Mishra M, Patil G, Mulkey S, Ramawat N, Pratap Singh V, Deshmukh R, Kumar Tripathi D, Nguyen HT, Sharma S. Avenues of the membrane transport system in adaptation of plants to abiotic stresses. Crit Rev Biotechnol 2019; 39:861-883. [DOI: 10.1080/07388551.2019.1616669] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Kanchan Vishwakarma
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, India
| | - Mitali Mishra
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, India
| | - Gunvant Patil
- Department of Agronomy and Plant Genetics, University of Minnesota St. Paul, Minnesota, MN, USA
| | - Steven Mulkey
- Department of Agronomy and Plant Genetics, University of Minnesota St. Paul, Minnesota, MN, USA
| | - Naleeni Ramawat
- Amity Institute of Organic Agriculture, Amity University, Uttar Pradesh, Noida, India
| | - Vijay Pratap Singh
- Department of Botany, C.M.P. Degree College, A Constituent Post Graduate College of University of Allahabad, Allahabad, India
| | - Rupesh Deshmukh
- National Agri-Food Biotechnology Institute (NABI), Mohali, India
| | | | - Henry T. Nguyen
- Department of Agronomy and Plant Genetics, University of Minnesota St. Paul, Minnesota, MN, USA
| | - Shivesh Sharma
- Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, India
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58
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Chen T, Wang W, Xu K, Xu Y, Ji D, Chen C, Xie C. K+ and Na+ transport contribute to K+/Na+ homeostasis in Pyropia haitanensis under hypersaline stress. ALGAL RES 2019. [DOI: 10.1016/j.algal.2019.101526] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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59
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Wang W, Paschalidis K, Feng JC, Song J, Liu JH. Polyamine Catabolism in Plants: A Universal Process With Diverse Functions. FRONTIERS IN PLANT SCIENCE 2019; 10:561. [PMID: 31134113 PMCID: PMC6513885 DOI: 10.3389/fpls.2019.00561] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 04/12/2019] [Indexed: 05/18/2023]
Abstract
Polyamine (PA) catabolic processes are performed by copper-containing amine oxidases (CuAOs) and flavin-containing PA oxidases (PAOs). So far, several CuAOs and PAOs have been identified in many plant species. These enzymes exhibit different subcellular localization, substrate specificity, and functional diversity. Since PAs are involved in numerous physiological processes, considerable efforts have been made to explore the functions of plant CuAOs and PAOs during the recent decades. The stress signal transduction pathways usually lead to increase of the intracellular PA levels, which are apoplastically secreted and oxidized by CuAOs and PAOs, with parallel production of hydrogen peroxide (H2O2). Depending on the levels of the generated H2O2, high or low, respectively, either programmed cell death (PCD) occurs or H2O2 is efficiently scavenged by enzymatic/nonenzymatic antioxidant factors that help plants coping with abiotic stress, recruiting different defense mechanisms, as compared to biotic stress. Amine and PA oxidases act further as PA back-converters in peroxisomes, also generating H2O2, possibly by activating Ca2+ permeable channels. Here, the new research data are discussed on the interconnection of PA catabolism with the derived H2O2, together with their signaling roles in developmental processes, such as fruit ripening, senescence, and biotic/abiotic stress reactions, in an effort to elucidate the mechanisms involved in crop adaptation/survival to adverse environmental conditions and to pathogenic infections.
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Affiliation(s)
- Wei Wang
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Konstantinos Paschalidis
- Department of Agriculture, School of Agricultural Sciences, Hellenic Mediterranean University, Heraklion, Greece
| | - Jian-Can Feng
- College of Horticulture, Henan Agricultural University, Zhengzhou, China
| | - Jie Song
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
| | - Ji-Hong Liu
- Key Laboratory of Horticultural Plant Biology, College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan, China
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60
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Wang W, Xu Y, Chen T, Xing L, Xu K, Xu Y, Ji D, Chen C, Xie C. Regulatory mechanisms underlying the maintenance of homeostasis in Pyropia haitanensis under hypersaline stress conditions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 662:168-179. [PMID: 30690352 DOI: 10.1016/j.scitotenv.2019.01.214] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 01/04/2019] [Accepted: 01/18/2019] [Indexed: 05/10/2023]
Abstract
Intertidal macroalgae are highly resistant to hypersaline stress conditions. However, the underlying mechanism remains unknown. In the present study, the mechanism behind Pyropia haitanensis responses to two hypersaline stress conditions [100‰ (HSS_100) and 110‰ (HSS_110)] was investigated via analyses of physiological and transcriptomic changes. We observed that the differences between the responses of Py. haitanensis to HSS_100 and HSS_110 conditions involved the following three aspects: osmotic regulation, ionic homeostasis, and adjustment to secondary stresses. First, the water retention of Py. haitanensis was maintained through increased expansin production under HSS_100 conditions, while cell wall pectin needed to be protected from hydrolysis via the increased abundance of a pectin methylesterase inhibitor under HSS_110 conditions. Meanwhile, Py. haitanensis achieved stable and rapid osmotic adjustments because of the coordinated accumulation of inorganic ions (K+, Na+, and Cl-) and organic osmolytes (glycine betaine and trehalose) under HSS_100 conditions, but not under HSS_110 conditions. Second, Py. haitanensis maintained a higher K+/Na+ ratio under HSS_100 conditions than under HSS_110 conditions, mainly via the export of Na+ into the apoplast rather than compartmentalizing it into the vacuoles, and the enhanced uptake and retention of K+. However, K+/Na+ homeostasis was not completely disrupted during a short-term exposure to HSS_110 conditions. Finally, the Py. haitanensis antioxidant system scavenged more ROS and synthesized more heat shock proteins under HSS_100 conditions than under HSS_110 conditions, although thalli may have been able to maintain a certain redox balance during a short-term exposure to HSS_110 conditions. These differences may explain why Py. haitanensis can adapt to HSS_100 conditions rather than HSS_110 conditions, and also why the thalli exposed to HSS_110 conditions can recover after being transferred to normal seawater. Thus, the data presented herein may elucidate the mechanisms enabling Pyropia species to tolerate the sudden and periodic changes in salinity typical of intertidal systems.
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Affiliation(s)
- Wenlei Wang
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Yan Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - TianXiang Chen
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Lei Xing
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Kai Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Yan Xu
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Dehua Ji
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Changsheng Chen
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China
| | - Chaotian Xie
- Fisheries College, Jimei University, Xiamen 361021, China; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Xiamen 361021, China.
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61
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Liu Y, Yu Y, Sun J, Cao Q, Tang Z, Liu M, Xu T, Ma D, Li Z, Sun J. Root-zone-specific sensitivity of K+-and Ca2+-permeable channels to H2O2 determines ion homeostasis in salinized diploid and hexaploid Ipomoea trifida. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1389-1405. [PMID: 30689932 PMCID: PMC6382330 DOI: 10.1093/jxb/ery461] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/11/2018] [Accepted: 12/19/2018] [Indexed: 05/13/2023]
Abstract
Polyploids generally possess superior K+/Na+ homeostasis under saline conditions compared with their diploid progenitors. In this study, we identified the physiological mechanisms involved in the ploidy-related mediation of K+/Na+ homeostasis in the roots of diploid (2x) and hexaploid (6x; autohexaploid) Ipomoea trifida, which is the closest relative of cultivated sweet potato. Results showed that 6x I. trifida retained more K+ and accumulated less Na+ in the root and leaf tissues under salt stress than 2x I. trifida. Compared with its 2x ancestor, 6x I. trifida efficiently prevents K+ efflux from the meristem root zone under salt stress through its plasma membrane (PM) K+-permeable channels, which have low sensitivity to H2O2. Moreover, 6x I. trifida efficiently excludes Na+ from the elongation and mature root zones under salt stress because of the high sensitivity of PM Ca2+-permeable channels to H2O2. Our results suggest the root-zone-specific sensitivity to H2O2 of PM K+- and Ca2+-permeable channels in the co-ordinated control of K+/Na+ homeostasis in salinized 2x and 6x I. trifida. This work provides new insights into the improved maintenance of K+/Na+ homeostasis of polyploids under salt stress.
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Affiliation(s)
- Yang Liu
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Yicheng Yu
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Jianying Sun
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Qinghe Cao
- Sweet Potato Research Institute (CAAS), Jiangsu Xuzhou Sweet Potato Research Institute, MOA Key Laboratory of Biology and Genetic Improvement of Sweet Potato, Xuzhou, Jiangsu, China
| | - Zhonghou Tang
- Sweet Potato Research Institute (CAAS), Jiangsu Xuzhou Sweet Potato Research Institute, MOA Key Laboratory of Biology and Genetic Improvement of Sweet Potato, Xuzhou, Jiangsu, China
| | - Meiyan Liu
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Tao Xu
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
| | - Daifu Ma
- Sweet Potato Research Institute (CAAS), Jiangsu Xuzhou Sweet Potato Research Institute, MOA Key Laboratory of Biology and Genetic Improvement of Sweet Potato, Xuzhou, Jiangsu, China
| | - Zongyun Li
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
- Correspondence: or
| | - Jian Sun
- Jiangsu Key Laboratory of Phylogenomics and Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou, Jiangsu, China
- Correspondence: or
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Shabala S. Linking ploidy level with salinity tolerance: NADPH-dependent 'ROS-Ca2+ hub' in the spotlight. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1063-1067. [PMID: 31222353 PMCID: PMC6382325 DOI: 10.1093/jxb/erz042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Affiliation(s)
- Sergey Shabala
- International Centre for Environmental Membrane Biology, Foshan University, Foshan, China
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia
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Li N, Du C, Ma B, Gao Z, Wu Z, Zheng L, Niu Y, Wang Y. Functional Analysis of Ion Transport Properties and Salt Tolerance Mechanisms of RtHKT1 from the Recretohalophyte Reaumuria trigyna. PLANT & CELL PHYSIOLOGY 2019; 60:85-106. [PMID: 30239906 DOI: 10.1093/pcp/pcy187] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Indexed: 05/13/2023]
Abstract
Reaumuria trigyna is an endangered recretohalophyte and a small archaic feral shrub that is endemic to arid and semi-arid plateau regions of Inner Mongolia, China. Based on transcriptomic data, we isolated a high-affinity potassium transporter gene (RtHKT1) from R. trigyna, which encoded a plasma membrane-localized protein. RtHKT1 was rapidly up-regulated by high Na+ or low K+ and exhibited different tissue-specific expression patterns before and after stress treatment. Transgenic yeast showed tolerance to high Na+ or low K+, while transgenic Arabidopsis exhibited tolerance to high Na+ and sensitivity to high K+, or high Na+-low K+, confirming that Na+ tolerance in transgenic Arabidopsis depends on a sufficient external K+ concentration. Under external high Na+, high K+ and low K+ conditions, transgenic yeast accumulated more Na+-K+, Na+ and K+, while transgenic Arabidopsis accumulated less Na+-more K+, more Na+ and more Na+-K+, respectively, indicating that the ion transport properties of RtHKT1 depend on the external Na+-K+ environment. Salt stress induced up-regulation of some ion transporter genes (AtSOS1/AtHAK5/AtKUP5-6), as well as down-regulation of some genes (AtNHX1/AtAVP1/AtKUP9-12), revealing that multi-ion-transporter synergism maintains Na+/K+ homeostasis under salt stress in transgenic Arabidopsis. Overexpression of RtHKT1 enhanced K+ accumulation and prevented Na+ transport from roots to shoots, improved biomass accumulation and Chl content in salt-stressed transgenic Arabidopsis. The proline content and relative water content increased significantly, and some proline biosynthesis genes (AtP5CS1 and AtP5CS2) were also up-regulated in salt-stressed transgenic plants. These results suggest that RtHKT1 confers salt tolerance on transgenic Arabidopsis by maintaining Na+/K+ homeostasis and osmotic homeostasis.
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Affiliation(s)
- Ningning Li
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Chao Du
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Binjie Ma
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Ziqi Gao
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Zhigang Wu
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Linlin Zheng
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Yiding Niu
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
| | - Yingchun Wang
- Key Laboratory of Herbage and Endemic Crop Biotechnology (Inner Mongolia University), Ministry of Education, College of Life Sciences, Inner Mongolia University, 24 Zhaojun Road, Hohhot, China
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Al-Younis I, Wong A, Lemtiri-Chlieh F, Schmöckel S, Tester M, Gehring C, Donaldson L. The Arabidopsis thaliana K +-Uptake Permease 5 (AtKUP5) Contains a Functional Cytosolic Adenylate Cyclase Essential for K + Transport. FRONTIERS IN PLANT SCIENCE 2018; 9:1645. [PMID: 30483296 PMCID: PMC6243130 DOI: 10.3389/fpls.2018.01645] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 10/23/2018] [Indexed: 05/24/2023]
Abstract
Potassium (K+) is the most abundant cation in plants, and its uptake and transport are key to growth, development and responses to the environment. Here, we report that Arabidopsis thaliana K+ uptake permease 5 (AtKUP5) contains an adenylate cyclase (AC) catalytic center embedded in its N-terminal cytosolic domain. The purified recombinant AC domain generates cAMP in vitro; and when expressed in Escherichia coli, increases cAMP levels in vivo. Both the AC domain and full length AtKUP5 rescue an AC-deficient E. coli mutant, cyaA, and together these data provide evidence that AtKUP5 functions as an AC. Furthermore, full length AtKUP5 complements the Saccharomyces cerevisiae K+ transport impaired mutant, trk1 trk2, demonstrating its function as a K+ transporter. Surprisingly, a point mutation in the AC center that impairs AC activity, also abolishes complementation of trk1 trk2, suggesting that a functional catalytic AC domain is essential for K+ uptake. AtKUP5-mediated K+ uptake is not affected by cAMP, the catalytic product of the AC, but, interestingly, causes cytosolic cAMP accumulation. These findings are consistent with a role for AtKUP5 as K+ flux sensor, where the flux-dependent cAMP increases modulate downstream components essential for K+ homeostasis, such as cyclic nucleotide gated channels.
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Affiliation(s)
- Inas Al-Younis
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Aloysius Wong
- College of Science and Technology, Wenzhou-Kean University, Wenzhou, China
| | - Fouad Lemtiri-Chlieh
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Sandra Schmöckel
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Mark Tester
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Chris Gehring
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Lara Donaldson
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa
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Greenway H, Armstrong W. Energy-crises in well-aerated and anoxic tissue: does tolerance require the same specific proteins and energy-efficient transport? FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:877-894. [PMID: 32291053 DOI: 10.1071/fp17250] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 02/20/2018] [Indexed: 06/11/2023]
Abstract
Many of the profound changes in metabolism that are caused by O2 deficiency also occur in well-aerated tissues when oxidative phosphorylation is partially or wholly inhibited. For these well-aerated tissues, reduction in energy formation occurs during exposure to inhibitors of oxidative phosphorylation, cold/chilling and wounding, so we prefer the term 'energy crisis' metabolism over 'anaerobic' metabolism. In this review, we note that the overwhelming body of data on energy crises has been obtained by exposure to hypoxia-anoxia, which we will indicate when discussing the particular experiments. We suggest that even transient survival of an energy crisis requires a network of changes common to a large number of conditions, ranging from changes in development to various adverse conditions such as high salinity, drought and nutrient deficiency, all of which reduce growth. During an energy crisis this general network needs to be complemented by energy specific proteins, including the so called 'anaerobic proteins' and the group of ERFVII transcription factors, which induces the synthesis of these proteins. Crucially, the difference between anoxia-intolerant and -tolerant tissues in the event of a severe energy crisis would mainly depend on changes in some 'key' energy crisis proteins: we suggest these proteins would include phytoglobin, the V-H+PPiase and pyruvate decarboxylase. A second characteristic of a high tolerance to an energy crisis is engagement of energy efficient transport. This feature includes a sharp reduction in rates of solute transport and use of energy-efficient modifications of transport systems by primary H+ transport and secondary H+-solute transport systems. Here we also discuss the best choice of species to study an energy crisis. Further, we consider confounding of the acclimative response by responses to injury, be it due to the use of tissues intolerant to an energy crisis, or to faulty techniques.
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Affiliation(s)
- Hank Greenway
- School of Plant Biology, Faculty of Science, the University of Western Australia, Crawley, WA 6009, Australia
| | - William Armstrong
- School of Plant Biology, Faculty of Science, the University of Western Australia, Crawley, WA 6009, Australia
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66
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Okada T, Yamane S, Yamaguchi M, Kato K, Shinmyo A, Tsunemitsu Y, Iwasaki K, Ueno D, Demura T. Characterization of rice KT/HAK/KUP potassium transporters and K + uptake by HAK1 from Oryza sativa. PLANT BIOTECHNOLOGY (TOKYO, JAPAN) 2018; 35:101-111. [PMID: 31819712 PMCID: PMC6879396 DOI: 10.5511/plantbiotechnology.18.0308a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/08/2018] [Indexed: 05/22/2023]
Abstract
Plant high-affinity K+ (HAK) transporters are divided into four major clusters. Cluster I transporters, in particular, are thought to have high-affinity for K+. Of the 27 HAK genes in rice, eight HAK transporters belong to cluster I. In this study, we investigated the temporal expression patterns during K+ deficiency and K+ transport activity of these eight HAK transporters. The expression of seven HAK genes except OsHAK20 was detected. Expression of OsHAK1, OsHAK5 and OsHAK21 was induced in response to K+ deficiency; however, that of other genes was not. Six of the eight HAK transporters-OsHAK1, OsHAK5, OsHAK19, OsHAK20, OsHAK21, and OsHAK27-complemented the K+-transporter-deficient yeast or bacterial strain. Further, the yeast cells expressing OsHAK1 were more sensitive to Na+ than those expressing OsHAK5. Mutant analysis showed that the high-affinity K+ uptake activity was almost undetectable in oshak1 mutants in a low-K+ medium (0.02 mM). In addition, the high-affinity K+ uptake activity of wild-type plants was inhibited by mild salt stress (20 mM NaCl); however, Na+ permeability of OsHAK1 was not detected in Escherichia coli cells. The high-affinity K+ uptake activity by leaf blades was detected in wild-type plants, while it was not detected in oshak1 mutants. Our results suggest that OsHAK1 and OsHAK5 are the two important components of cluster I corresponding to low-K+ conditions, and that the transport activity of OsHAK1, unlike that of OsHAK5, is sensitive to Na+. Further, OsHAK1 is suggested to involve in foliar K+ uptake.
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Affiliation(s)
- Tomoyuki Okada
- Faculty of Agriculture, Kochi University, 200 Otsu Monobe, Nankoku, Kochi 783-8502, Japan
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
- Kochi Agricultural Research Center, 1100 Hataeda, Nankoku, Kochi 783-0023, Japan
- E-mail: Tel & Fax: +81-88-864-5179
| | - Sousuke Yamane
- Faculty of Agriculture, Kochi University, 200 Otsu Monobe, Nankoku, Kochi 783-8502, Japan
| | - Masatoshi Yamaguchi
- Graduate School of Biological Engineering, Saitama University, 255 Shimo-Ohkubo, Sakura-ku, Saitama 338-8570, Japan
| | - Ko Kato
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Atsuhiko Shinmyo
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Yuta Tsunemitsu
- Faculty of Agriculture, Kochi University, 200 Otsu Monobe, Nankoku, Kochi 783-8502, Japan
| | - Kozo Iwasaki
- Faculty of Agriculture, Kochi University, 200 Otsu Monobe, Nankoku, Kochi 783-8502, Japan
| | - Daisei Ueno
- Faculty of Agriculture, Kochi University, 200 Otsu Monobe, Nankoku, Kochi 783-8502, Japan
| | - Taku Demura
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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Ahmad H, Hayat S, Ali M, Liu T, Cheng Z. The combination of arbuscular mycorrhizal fungi inoculation ( Glomus versiforme) and 28-homobrassinolide spraying intervals improves growth by enhancing photosynthesis, nutrient absorption, and antioxidant system in cucumber ( Cucumis sativus L.) under salinity. Ecol Evol 2018; 8:5724-5740. [PMID: 29938088 PMCID: PMC6010694 DOI: 10.1002/ece3.4112] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/22/2018] [Accepted: 03/26/2018] [Indexed: 01/27/2023] Open
Abstract
Salinity is one of the major obstacles in the agriculture industry causing huge losses in productivity. Several strategies such as plant growth regulators with arbuscular mycorrhizal fungi (AMF) have been used to decrease the negative effects of salt stress. In our experiment, 28-homobrassinolide (HBL) with spraying intervals was combined with AMF (Glomus versiforme) in cucumber cultivars Jinyou 1# (salt sensitive) and (Changchun mici, in short, CCMC, salt tolerant) under NaCl (100 mmol/L). Studies have documented that the foliar application of HBL and AMF colonization can enhance tolerance to plants under stress conditions. However, the mechanism of the HBL spraying intervals after 15 and 30 days in combination with AMF in cucumber under salt stress is still unknown. Our results revealed that the HBL spraying interval after 15 days in combination with AMF resulted in improved growth, photosynthesis, and decreased sodium toxicity under NaCl. Moreover, the antioxidant enzymes SOD (superoxide dismutase; EC 1.15.1.1) and POD activity (peroxidase; EC 1.11.1.7) showed a gradual increase after every 10 days, while the CAT (catalase; EC 1.11.1.6) increased after 30 days of salt treatments in both cultivars. This research suggests that the enhanced tolerance to salinity was mainly related to elevated levels of antioxidant enzymes and lower uptake of Na+, which lowers the risk of ion toxicity and decreases cell membrane damage.
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Affiliation(s)
- Husain Ahmad
- College of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
| | - Sikandar Hayat
- College of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
| | - Muhammad Ali
- College of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
| | - Tao Liu
- College of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
| | - Zhihui Cheng
- College of HorticultureNorthwest A&F UniversityYanglingShaanxiChina
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68
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Wang H, Shabala L, Zhou M, Shabala S. Hydrogen Peroxide-Induced Root Ca 2+ and K⁺ Fluxes Correlate with Salt Tolerance in Cereals: Towards the Cell-Based Phenotyping. Int J Mol Sci 2018; 19:E702. [PMID: 29494514 PMCID: PMC5877563 DOI: 10.3390/ijms19030702] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 02/16/2018] [Accepted: 02/22/2018] [Indexed: 12/25/2022] Open
Abstract
Salinity stress-induced production of reactive oxygen species (ROS) and associated oxidative damage is one of the major factors limiting crop production in saline soils. However, the causal link between ROS production and stress tolerance is not as straightforward as one may expect, as ROS may also play an important signaling role in plant adaptive responses. In this study, the causal relationship between salinity and oxidative stress tolerance in two cereal crops-barley (Hordeum vulgare) and wheat (Triticum aestivum)-was investigated by measuring the magnitude of ROS-induced net K⁺ and Ca2+ fluxes from various root tissues and correlating them with overall whole-plant responses to salinity. We have found that the association between flux responses to oxidative stress and salinity stress tolerance was highly tissue specific, and was also dependent on the type of ROS applied. No correlation was found between root responses to hydroxyl radicals and the salinity tolerance. However, when oxidative stress was administered via H₂O₂ treatment, a significant positive correlation was found for the magnitude of ROS-induced K⁺ efflux and Ca2+ uptake in barley and the overall salinity stress tolerance, but only for mature zone and not the root apex. The same trends were found for wheat. These results indicate high tissue specificity of root ion fluxes response to ROS and suggest that measuring the magnitude of H₂O₂-induced net K⁺ and Ca2+ fluxes from mature root zone may be used as a tool for cell-based phenotyping in breeding programs aimed to improve salinity stress tolerance in cereals.
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Affiliation(s)
- Haiyang Wang
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Lana Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia.
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia.
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69
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Gill MB, Zeng F, Shabala L, Böhm J, Zhang G, Zhou M, Shabala S. The ability to regulate voltage-gated K+-permeable channels in the mature root epidermis is essential for waterlogging tolerance in barley. JOURNAL OF EXPERIMENTAL BOTANY 2018; 69:667-680. [PMID: 29301054 PMCID: PMC5853535 DOI: 10.1093/jxb/erx429] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/17/2017] [Indexed: 05/19/2023]
Abstract
Oxygen depletion under waterlogged conditions results in a compromised operation of H+-ATPase, with strong implications for membrane potential maintenance, cytosolic pH homeostasis, and transport of all nutrients across membranes. The above effects, however, are highly tissue specific and time dependent, and the causal link between hypoxia-induced changes to the cell's ionome and plant adaptive responses to hypoxia is not well established. This work aimed to fill this gap and investigate the effects of oxygen deprivation on K+ signalling and homeostasis in plants, and potential roles of GORK (depolarization-activated outward-rectifying potassium) channels in adaptation to oxygen-deprived conditions in barley. A significant K+ loss was observed in roots exposed to hypoxic conditions; this loss correlated with the cell's viability. Stress-induced K+ loss was stronger in the root apex immediately after stress onset, but became more pronounced in the root base as the stress progressed. The amount of K+ in shoots of plants grown in waterlogged soil correlated strongly with K+ flux under hypoxia measured in laboratory experiments. Hypoxia induced membrane depolarization; the severity of this depolarization was less pronounced in the tolerant group of cultivars. The expression of GORK was down-regulated by 1.5-fold in mature root but it was up-regulated by 10-fold in the apex after 48 h hypoxia stress. Taken together, our results suggest that the GORK channel plays a central role in K+ retention and signalling under hypoxia stress, and measuring hypoxia-induced K+ fluxes from the mature root zone may be used as a physiological marker to select waterlogging-tolerant varieties in breeding programmes.
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Affiliation(s)
- Muhammad Bilal Gill
- Department of Agronomy, Zhejiang University, Hangzhou, China
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Fanrong Zeng
- Department of Agronomy, Zhejiang University, Hangzhou, China
| | - Lana Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Jennifer Böhm
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Guoping Zhang
- Department of Agronomy, Zhejiang University, Hangzhou, China
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
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Zeng Y, Li Q, Wang H, Zhang J, Du J, Feng H, Blumwald E, Yu L, Xu G. Two NHX-type transporters from Helianthus tuberosus improve the tolerance of rice to salinity and nutrient deficiency stress. PLANT BIOTECHNOLOGY JOURNAL 2018; 16:310-321. [PMID: 28627026 PMCID: PMC5785360 DOI: 10.1111/pbi.12773] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/30/2017] [Accepted: 06/08/2017] [Indexed: 05/18/2023]
Abstract
The NHX-type cation/H+ transporters in plants have been shown to mediate Na+ (K+ )/H+ exchange for salinity tolerance and K+ homoeostasis. In this study, we identified and characterized two NHX homologues, HtNHX1 and HtNHX2 from an infertile and salinity tolerant species Helianthus tuberosus (cv. Nanyu No. 1). HtNHX1 and HtNHX2 share identical 5'- and 3'-UTR and coding regions, except for a 342-bp segment encoding 114 amino acids (L272 to Q385 ) which is absent in HtNHX2. Both hydroponics and soil culture experiments showed that the expression of HtNHX1 or HtNHX2 improved the rice tolerance to salinity. Expression of HtNHX2, but not HtNHX1, increased rice grain yield, harvest index, total nutrient uptake under K+ -limited salt-stress or general nutrient deficiency conditions. The results provide a novel insight into NHX function in plant mineral nutrition.
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Affiliation(s)
- Yang Zeng
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Qing Li
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Haiya Wang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Jianliang Zhang
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Jia Du
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Huimin Feng
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | | | - Ling Yu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm EnhancementNanjing Agricultural UniversityNanjingChina
- Key Laboratory of Plant Nutrition and Fertilization in Low‐Middle Reaches of the Yangtze RiverMinistry of AgricultureNanjing Agricultural UniversityNanjingChina
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71
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Demidchik V, Shabala S. Mechanisms of cytosolic calcium elevation in plants: the role of ion channels, calcium extrusion systems and NADPH oxidase-mediated 'ROS-Ca 2+ Hub'. FUNCTIONAL PLANT BIOLOGY : FPB 2018; 45:9-27. [PMID: 32291018 DOI: 10.1071/fp16420] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 12/07/2016] [Indexed: 05/22/2023]
Abstract
Elevation in the cytosolic free calcium is crucial for plant growth, development and adaptation. Calcium influx into plant cells is mediated by Ca2+ depolarisation-activated, hyperpolarisation-activated and voltage-independent Ca2+-permeable channels (DACCs, HACCs and VICCs respectively). These channels are encoded by the following gene families: (1) cyclic nucleotide-gated channels (CNGCs), (2) ionotropic glutamate receptors (GLRs), (3) annexins, (4) 'mechanosensitive channels of small (MscS) conductance'-like channels (MSLs), (5) 'mid1-complementing activity' channels (MCAs), Piezo channels, and hyperosmolality-induced [Ca2+]cyt. channel 1 (OSCA1). Also, a 'tandem-pore channel1' (TPC1) catalyses Ca2+ efflux from the vacuole in response to the plasma membrane-mediated Ca2+ elevation. Recent experimental data demonstrated that Arabidopsis thaliana (L.) Heynh. CNGCs 2, 5-10, 14, 16 and 18, GLRs 1.2, 3.3, 3.4, 3.6 and 3.7, TPC1, ANNEXIN1, MSL9 and MSL10,MCA1 and MCA2, OSCA1, and some their homologues counterparts in other species, are responsible for Ca2+ currents and/or cytosolic Ca2+ elevation. Extrusion of Ca2+ from the cytosol is mediated by Ca2+-ATPases and Ca2+/H+ exchangers which were recently examined at the level of high resolution crystal structure. Calcium-activated NADPH oxidases and reactive oxygen species (ROS)-activated Ca2+ conductances form a self-amplifying 'ROS-Ca2+hub', enhancing and transducing Ca2+ and redox signals. The ROS-Ca2+ hub contributes to physiological reactions controlled by ROS and Ca2+, demonstrating synergism and unity of Ca2+ and ROS signalling mechanisms.
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Affiliation(s)
- Vadim Demidchik
- Department of Plant Cell Biology and Bioengineering, Biological Faculty, Belarusian State University, 4 Independence Avenue, Minsk, 220030, Belarus
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
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Gill MB, Zeng F, Shabala L, Zhang G, Fan Y, Shabala S, Zhou M. Cell-Based Phenotyping Reveals QTL for Membrane Potential Maintenance Associated with Hypoxia and Salinity Stress Tolerance in Barley. FRONTIERS IN PLANT SCIENCE 2017; 8:1941. [PMID: 29201033 PMCID: PMC5696338 DOI: 10.3389/fpls.2017.01941] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 10/27/2017] [Indexed: 05/18/2023]
Abstract
Waterlogging and salinity are two major abiotic stresses that hamper crop production world-wide resulting in multibillion losses. Plant abiotic stress tolerance is conferred by many interrelated mechanisms. Amongst these, the cell's ability to maintain membrane potential (MP) is considered to be amongst the most crucial traits, a positive relationship between the ability of plants to maintain highly negative MP and its tolerance to both salinity and waterlogging stress. However, no attempts have been made to identify quantitative trait loci (QTL) conferring this trait. In this study, the microelectrode MIFE technique was used to measure the plasma membrane potential of epidermal root cells of 150 double haploid (DH) lines of barley (Hordeum vulgare L.) from a cross between a Chinese landrace TX9425 and Japanese malting cultivar Naso Nijo under hypoxic conditions. A major QTL for the MP in the epidermal root cells in hypoxia-exposed plants was identified. This QTL was located on 2H, at a similar position to the QTL for waterlogging and salinity tolerance reported in previous studies. Further analysis confirmed that MP showed a significant contribution to both waterlogging and salinity tolerance. The fact that the QTL for MP was controlled by a single major QTL illustrates the power of the single-cell phenotyping approach and opens prospects for fine mapping this QTL and thus being more effective in marker assisted selection.
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Affiliation(s)
- Muhammad B. Gill
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
- School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Fanrong Zeng
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Lana Shabala
- School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Guoping Zhang
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China
| | - Yun Fan
- School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, TAS, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Hobart, TAS, Australia
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73
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Kumar S, Kalita A, Srivastava R, Sahoo L. Co-expression of Arabidopsis NHX1 and bar Improves the Tolerance to Salinity, Oxidative Stress, and Herbicide in Transgenic Mungbean. FRONTIERS IN PLANT SCIENCE 2017; 8:1896. [PMID: 29163616 PMCID: PMC5673651 DOI: 10.3389/fpls.2017.01896] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2017] [Accepted: 10/19/2017] [Indexed: 05/11/2023]
Abstract
Mungbean is an important pulse crop extensively cultivated in Southeast Asia for supply of easily digestible protein. Salinity severely limits the growth and productivity of mungbean, and weeding poses nutritional and disease constraints to mungbean cultivation. To pyramid both salt tolerance and protection against herbicide in mungbean, the AtNHX1 encoding tonoplast Na+/H+ antiporter from Arabidopsis, and bar gene associated with herbicide resistance were co-expressed through Agrobacterium-mediated transformation. Stress inducible expression of AtNHX1 significantly improved tolerance under salt stress to ionic, osmotic, and oxidative stresses in transgenic mungbean plants compared to the wild type (WT) plants, whereas constitutive expression of bar provided resistance to herbicide. Compared to WT, transgenic mungbean plants grew better with higher plant height, foliage, dry mass and seed yield under high salt stress (200 mM NaCl) in the greenhouse. The improved performance of transgenic plants under salt stress was associated with enhanced sequestration of Na+ in roots by vacuolar Na+/H+ antiporter and limited transport of toxic Na+ to shoots, possibly by restricting Na+ influx into shoots. Transgenic plants showed better intracellular ion homeostasis, osmoregulation, reduced cell membrane damage, improved photosynthetic capacity, and transpiration rate as compared to WT when subjected to salt stress. Reduction in hydrogen peroxide and oxygen radical production indicated enhanced protection of transgenic plants to both salt- and methyl vialogen (MV)-induced oxidative stress. This study laid a firm foundation for improving mungbean yield in saline lands in Southeast Asia.
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Affiliation(s)
| | | | | | - Lingaraj Sahoo
- Department of Bioscience and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India
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74
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Ahanger MA, Tomar NS, Tittal M, Argal S, Agarwal RM. Plant growth under water/salt stress: ROS production; antioxidants and significance of added potassium under such conditions. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2017; 23:731-744. [PMID: 29158624 PMCID: PMC5671444 DOI: 10.1007/s12298-017-0462-7] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 07/31/2017] [Indexed: 05/18/2023]
Abstract
Plants are confronted with a variety of environmenmtal stresses resulting in enhanced production of ROS. Plants require a threshold level of ROS for vital functions and any change in their concentration alters the entire physiology of plant. Delicate balance of ROS is maintained by an efficient functioning of intriguing indigenous defence system called antioxidant system comprising enzymatic and non enzymatic components. Down regulation of antioxidant system leads to ROS induced oxidative stress causing damage to important cellular structures and hence anomalies in metabolism. Proper mineral nutrition, in addition to other agricultural practices, forms an important part for growth and hence the yield. Potassium (K) is a key macro-element regulating growth and development through alterations in physiological and biochemical attributes. K has been reported to result into accumulation of osmolytes and augmentation of antioxidant components in the plants exposed to water and salt stress. In the present review an effort has been made to revisit the old findings and the current advances in research regarding the role of optimal, suboptimal and deficient K soil status on growth under normal and stressful conditions. Effect of K deficiency and sufficiency is discussed and the information about the K mediated antioxidant regulation and plant response is highlighted.
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Affiliation(s)
| | - Nisha Singh Tomar
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
| | - Megha Tittal
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
| | - Surendra Argal
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
| | - R. M. Agarwal
- School of Studies in Botany, Jiwaji University, Gwalior, MP 474011 India
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75
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Rogiers SY, Coetzee ZA, Walker RR, Deloire A, Tyerman SD. Potassium in the Grape ( Vitis vinifera L.) Berry: Transport and Function. FRONTIERS IN PLANT SCIENCE 2017; 8:1629. [PMID: 29021796 PMCID: PMC5623721 DOI: 10.3389/fpls.2017.01629] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 09/05/2017] [Indexed: 05/20/2023]
Abstract
K+ is the most abundant cation in the grape berry. Here we focus on the most recent information in the long distance transport and partitioning of K+ within the grapevine and postulate on the potential role of K+ in berry sugar accumulation, berry water relations, cellular growth, disease resistance, abiotic stress tolerance and mitigating senescence. By integrating information from several different plant systems we have been able to generate new hypotheses on the integral functions of this predominant cation and to improve our understanding of how these functions contribute to grape berry growth and ripening. Valuable contributions to the study of K+ in membrane stabilization, turgor maintenance and phloem transport have allowed us to propose a mechanistic model for the role of this cation in grape berry development.
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Affiliation(s)
- Suzy Y. Rogiers
- New South Wales Department of Primary Industries, Wagga Wagga, NSW, Australia
- National Wine and Grape Industry Centre, Charles Sturt University, Wagga Wagga, NSW, Australia
- The Australian Research Council Training Centre for Innovative Wine Production, University of Adelaide, Glen Osmond, SA, Australia
| | - Zelmari A. Coetzee
- National Wine and Grape Industry Centre, Charles Sturt University, Wagga Wagga, NSW, Australia
- The Australian Research Council Training Centre for Innovative Wine Production, University of Adelaide, Glen Osmond, SA, Australia
- School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
| | - Rob R. Walker
- The Australian Research Council Training Centre for Innovative Wine Production, University of Adelaide, Glen Osmond, SA, Australia
- School of Agricultural and Wine Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia
- Agriculture and Food (CSIRO), Glen Osmond, SA, Australia
- School of Agriculture, Food, and Wine, University of Adelaide, Urrbrae, SA, Australia
| | - Alain Deloire
- National Wine and Grape Industry Centre, Charles Sturt University, Wagga Wagga, NSW, Australia
- The Australian Research Council Training Centre for Innovative Wine Production, University of Adelaide, Glen Osmond, SA, Australia
- Department of Biology-Ecology, SupAgro, Montpellier, France
| | - Stephen D. Tyerman
- The Australian Research Council Training Centre for Innovative Wine Production, University of Adelaide, Glen Osmond, SA, Australia
- School of Agriculture, Food, and Wine, University of Adelaide, Urrbrae, SA, Australia
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76
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Kiani-Pouya A, Roessner U, Jayasinghe NS, Lutz A, Rupasinghe T, Bazihizina N, Bohm J, Alharbi S, Hedrich R, Shabala S. Epidermal bladder cells confer salinity stress tolerance in the halophyte quinoa and Atriplex species. PLANT, CELL & ENVIRONMENT 2017; 40:1900-1915. [PMID: 28558173 DOI: 10.1111/pce.12995] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 05/21/2017] [Indexed: 05/02/2023]
Abstract
Epidermal bladder cells (EBCs) have been postulated to assist halophytes in coping with saline environments. However, little direct supporting evidence is available. Here, Chenopodium quinoa plants were grown under saline conditions for 5 weeks. One day prior to salinity treatment, EBCs from all leaves and petioles were gently removed by using a soft cosmetic brush and physiological, ionic and metabolic changes in brushed and non-brushed leaves were compared. Gentle removal of EBC neither initiated wound metabolism nor affected the physiology and biochemistry of control-grown plants but did have a pronounced effect on salt-grown plants, resulting in a salt-sensitive phenotype. Of 91 detected metabolites, more than half were significantly affected by salinity. Removal of EBC dramatically modified these metabolic changes, with the biggest differences reported for gamma-aminobutyric acid (GABA), proline, sucrose and inositol, affecting ion transport across cellular membranes (as shown in electrophysiological experiments). This work provides the first direct evidence for a role of EBC in salt tolerance in halophytes and attributes this to (1) a key role of EBC as a salt dump for external sequestration of sodium; (2) improved K+ retention in leaf mesophyll and (3) EBC as a storage space for several metabolites known to modulate plant ionic relations.
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Affiliation(s)
- Ali Kiani-Pouya
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
| | - Ute Roessner
- School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Nirupama S Jayasinghe
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Adrian Lutz
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Thusitha Rupasinghe
- Metabolomics Australia, School of BioSciences, The University of Melbourne, 3010, Parkville, Victoria, Australia
| | - Nadia Bazihizina
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
- Deptartment of Agrifood Production and Environmental Science, University of Florence, I-50019, Florence, Italy
| | - Jennifer Bohm
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, Würzburg University, 97082, Wurzburg, Germany
| | - Sulaiman Alharbi
- Zoology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia
| | - Rainer Hedrich
- Institute for Molecular Plant Physiology and Biophysics, Biocenter, Würzburg University, 97082, Wurzburg, Germany
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, 7001, Hobart, Tasmania, Australia
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77
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Falakboland Z, Zhou M, Zeng F, Kiani-Pouya A, Shabala L, Shabala S. Plant ionic relation and whole-plant physiological responses to waterlogging, salinity and their combination in barley. FUNCTIONAL PLANT BIOLOGY : FPB 2017; 44:941-953. [PMID: 32480622 DOI: 10.1071/fp16385] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 05/10/2017] [Indexed: 06/11/2023]
Abstract
Waterlogging and salinity stresses significantly affect crop growth and global food production, and these stresses are often interrelated because waterlogging can lead to land salinisation by transporting salts to the surface. Although the physiological and molecular mechanisms of plant responses to each of these environmental constraints have been studied in detail, fewer studies have dealt with potential mechanisms underlying plant tolerance to the combined stress. This gap in knowledge is jeopardising the success of breeding programs. In the present work we studied the physiological and agronomical responses of 12 barley varieties contrasting in salinity stress tolerance to waterlogging (WL), salinity (NaCl) and combined (WL/NaCl) stresses. Stress damage symptoms were much greater in plants under combined WL/NaCl stress than those under separate stresses. The shoot biomass, chlorophyll content, maximum photochemical efficiency of PSII and shoot K+ concentration were significantly reduced under WL/NaCl conditions, whereas shoot Na+ concentration increased. Plants exposed to salinity stress showed lower damage indexes compared with WL. Chlorophyll fluorescence Fv/Fm value showed the highest correlation with the stress damage index under WL/NaCl conditions (r=-0.751) compared with other measured physiological traits, so was nominated as a good parameter to rank the tolerance of varieties. Average FW was reduced to 73±2, 52±1 and 23±2 percent of the control under NaCl, WL and combined WL/NaCl treatments respectively. Generally, the adverse effect of WL/NaCl stress was much greater in salt-sensitive varieties than in more tolerant varieties. Na+ concentrations of the shoot under control conditions were 97±10µmolg-1 DW, and increased to 1519±123, 179±11 and 2733±248µmolg-1 under NaCl, WL and combined WL/NaCl stresses respectively. K+ concentrations were 1378±66, 1260±74, 1270±79 and 411±92µmolg-1 DW under control, NaCl, WL and combined WL/NaCl stresses respectively. No significant correlation was found between the overall salinity stress tolerance and amount of Na+ accumulated in plant shoots after 15 days of exposure to 250mM NaCl stress. However, plants exposed to combined salinity and WL stress showed a negative correlation between shoot Na+ accumulation and extent of salinity damage. Overall, the reported results indicate that K+ reduction in the plants under combined WL/NaCl stress, but not stress-induced Na+ accumulation in the shoot, was the most critical feature in determining the overall plant performance under combined stress conditions.
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Affiliation(s)
- Zhinous Falakboland
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Fanrong Zeng
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Ali Kiani-Pouya
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart, Tas. 7001, Australia
| | - Lana Shabala
- 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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78
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Luo Q, Wei Q, Wang R, Zhang Y, Zhang F, He Y, Zhou S, Feng J, Yang G, He G. BdCIPK31, a Calcineurin B-Like Protein-Interacting Protein Kinase, Regulates Plant Response to Drought and Salt Stress. FRONTIERS IN PLANT SCIENCE 2017; 8:1184. [PMID: 28736568 PMCID: PMC5500663 DOI: 10.3389/fpls.2017.01184] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 06/21/2017] [Indexed: 05/06/2023]
Abstract
Calcineurin B-like protein interacting protein kinases (CIPKs) are vital elements in plant abiotic stress signaling pathways. However, the functional mechanism of CIPKs has not been understood clearly, especially in Brachypodium distachyon, a new monocot model plant. In this study, BdCIPK31, a CIPK gene from B. distachyon was characterized. BdCIPK31 was downregulated by polyethylene glycol, NaCl, H2O2, and abscisic acid (ABA) treatments. Transgenic tobacco plants overexpressing BdCIPK31 presented improved drought and salt tolerance, and displayed hypersensitive response to exogenous ABA. Further investigations revealed that BdCIPK31 functioned positively in ABA-mediated stomatal closure, and transgenic tobacco exhibited reduced water loss under dehydration conditions compared with the controls. BdCIPK31 also affected Na+/K+ homeostasis and root K+ loss, which contributed to maintain intracellular ion homeostasis under salt conditions. Moreover, the reactive oxygen species scavenging system and osmolyte accumulation were enhanced by BdCIPK31 overexpression, which were conducive for alleviating oxidative and osmotic damages. Additionally, overexpression of BdCIPK31 could elevate several stress-associated gene expressions under stress conditions. In conclusion, BdCIPK31 functions positively to drought and salt stress through ABA signaling pathway. Overexpressing BdCIPK31 functions in stomatal closure, ion homeostasis, ROS scavenging, osmolyte biosynthesis, and transcriptional regulation of stress-related genes.
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Affiliation(s)
- Qingchen Luo
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Qiuhui Wei
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Ruibin Wang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Yang Zhang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Fan Zhang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Yuan He
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Shiyi Zhou
- Hubei University of EducationWuhan, China
| | - Jialu Feng
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Guangxiao Yang
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
| | - Guangyuan He
- The Genetic Engineering International Cooperation Base of Chinese Ministry of Science and Technology, Key Laboratory of Molecular Biophysics of Chinese Ministry of Education, College of Life Science and Technology, Huazhong University of Science and TechnologyWuhan, China
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79
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Insight into the Recent Genome Duplication of the Halophilic Yeast Hortaea werneckii: Combining an Improved Genome with Gene Expression and Chromatin Structure. G3-GENES GENOMES GENETICS 2017; 7:2015-2022. [PMID: 28500048 PMCID: PMC5499112 DOI: 10.1534/g3.117.040691] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Extremophilic organisms demonstrate the flexibility and adaptability of basic biological processes by highlighting how cell physiology adapts to environmental extremes. Few eukaryotic extremophiles have been well studied and only a small number are amenable to laboratory cultivation and manipulation. A detailed characterization of the genome architecture of such organisms is important to illuminate how they adapt to environmental stresses. One excellent example of a fungal extremophile is the halophile Hortaea werneckii (Pezizomycotina, Dothideomycetes, Capnodiales), a yeast-like fungus able to thrive at near-saturating concentrations of sodium chloride and which is also tolerant to both UV irradiation and desiccation. Given its unique lifestyle and its remarkably recent whole genome duplication, H. werneckii provides opportunities for testing the role of genome duplications and adaptability to extreme environments. We previously assembled the genome of H. werneckii using short-read sequencing technology and found a remarkable degree of gene duplication. Technology limitations, however, precluded high-confidence annotation of the entire genome. We therefore revisited the H. wernickii genome using long-read, single-molecule sequencing and provide an improved genome assembly which, combined with transcriptome and nucleosome analysis, provides a useful resource for fungal halophile genomics. Remarkably, the ∼50 Mb H. wernickii genome contains 15,974 genes of which 95% (7608) are duplicates formed by a recent whole genome duplication (WGD), with an average of 5% protein sequence divergence between them. We found that the WGD is extraordinarily recent, and compared to Saccharomyces cerevisiae, the majority of the genome’s ohnologs have not diverged at the level of gene expression of chromatin structure.
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80
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Ahanger MA, Agarwal RM. Potassium up-regulates antioxidant metabolism and alleviates growth inhibition under water and osmotic stress in wheat (Triticum aestivum L). PROTOPLASMA 2017; 254:1471-1486. [PMID: 27783181 DOI: 10.1007/s00709-016-1037-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 10/19/2016] [Indexed: 05/22/2023]
Abstract
Pot experiments were conducted to find out the effectivity of K on Triticum aestivum L cultivars. Polyethylene glycol 6000 (PEG 6000) was used as an osmoticum to induce osmotic stress under sand culture setting up the water potential of external solution at -3 and -5 bars. In pots, plants were raised under restricted and normal irrigation and K was applied in varying doses (0, 20, 40, 60 kg ha-1) and estimation of different physiological and biochemical parameters was done at two developmental stages, i.e., preflowering and flowering. Supplementation of K resulted in obvious increase in growth and activity of antioxidant enzymes in both normal and stressed plants. Added potassium increased total phenols and tannins thereby strengthening the components of both the enzymatic as well as non-enzymatic antioxidant system. Under both normal and stressed conditions, K-fed plants experienced significant increase in the synthesis of osmolytes like free proline, amino acids, and sugars which assumes special significance in growth under water stress conditions. Wheat plants accumulating greater K were able to counteract the water stress-induced changes by maintaining lower Na/K ratio.
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Affiliation(s)
| | - R M Agarwal
- School of Studies in Botany, Jiwaji University, Gwalior, 474011, India
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81
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Wang F, Chen ZH, Liu X, Colmer TD, Shabala L, Salih A, Zhou M, Shabala S. Revealing the roles of GORK channels and NADPH oxidase in acclimation to hypoxia in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3191-3204. [PMID: 28338729 PMCID: PMC5853854 DOI: 10.1093/jxb/erw378] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 09/20/2016] [Indexed: 05/19/2023]
Abstract
Regulation of root cell K+ is essential for acclimation to low oxygen stress. The potential roles of GORK (depolarization-activated guard cell outward-rectifying potassium) channels and RBOHD (respiratory burst oxidase homologue D) in plant adaptive responses to hypoxia were investigated in the context of tissue specificity (epidermis versus stele; elongation versus mature zone) in roots of Arabidopsis. The expression of GORK and RBOHD was down-regulated by 2- to 3-fold within 1 h and 24 h of hypoxia treatment in Arabidopsis wild-type (WT) roots. Interestingly, a loss of the functional GORK channel resulted in a waterlogging-tolerant phenotype, while rbohD knockout was sensitive to waterlogging. To understand their functions under hypoxia stress, we studied K+, Ca2+, and reactive oxygen species (ROS) distribution in various root cell types. gork1-1 plants had better K+ retention ability in both the elongation and mature zone compared with the WT and rbohD under hypoxia. Hypoxia induced a Ca2+ increase in each cell type after 72 h, and the increase was much less pronounced in rbohD than in the WT. In most tissues except the elongation zone in rbohD, the H2O2 concentration had decreased after 1 h of hypoxia, but then increased significantly after 24 h of hypoxia in each zone and tissue, further suggesting that RBOHD may shape hypoxia-specific Ca2+ signatures via the modulation of apoplastic H2O2 production. Taken together, our data suggest that plants lacking functional GORK channels are more capable of retaining K+ for their better performance under hypoxia, and that RBOHD is crucial in hypoxia-induced Ca2+ signalling for stress sensing and acclimation mechanism.
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Affiliation(s)
- Feifei Wang
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Zhong-Hua Chen
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Xiaohui Liu
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
- School of Light Industry Engineering, Guizhou Institute of Technology, Guiyang, China
| | - Timothy D Colmer
- School of Plant Biology and Institute of Agriculture, The University of Western Australia, Crawley, WA, Australia
| | - Lana Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Anya Salih
- School of Science and Health, Hawkesbury Institute for the Environment, Western Sydney University, Penrith, NSW, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
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82
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Razzaque S, Haque T, Elias SM, Rahman MS, Biswas S, Schwartz S, Ismail AM, Walia H, Juenger TE, Seraj ZI. Reproductive stage physiological and transcriptional responses to salinity stress in reciprocal populations derived from tolerant (Horkuch) and susceptible (IR29) rice. Sci Rep 2017; 7:46138. [PMID: 28397857 PMCID: PMC5387399 DOI: 10.1038/srep46138] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Accepted: 03/13/2017] [Indexed: 12/29/2022] Open
Abstract
Global increase in salinity levels has made it imperative to identify novel sources of genetic variation for tolerance traits, especially in rice. The rice landrace Horkuch, endemic to the saline coastal area of Bangladesh, was used in this study as the source of tolerance in reciprocal crosses with the sensitive but high-yielding IR29 variety for discovering transcriptional variation associated with salt tolerance in the resulting populations. The cytoplasmic effect of the Horkuch background in leaves under stress showed functional enrichment for signal transduction, DNA-dependent regulation and transport activities. In roots the enrichment was for cell wall organization and macromolecule biosynthesis. In contrast, the cytoplasmic effect of IR29 showed upregulation of apoptosis and downregulation of phosphorylation across tissues relative to Horkuch. Differential gene expression in leaves of the sensitive population showed downregulation of GO processes like photosynthesis, ATP biosynthesis and ion transport. Roots of the tolerant plants conversely showed upregulation of GO terms like G-protein coupled receptor pathway, membrane potential and cation transport. Furthermore, genes involved in regulating membrane potentials were constitutively expressed only in the roots of tolerant individuals. Overall our work has developed genetic resources and elucidated the likely mechanisms associated with the tolerance response of the Horkuch genotype.
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Affiliation(s)
- Samsad Razzaque
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | - Taslima Haque
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | - Sabrina M. Elias
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583, USA
| | - Md. Sazzadur Rahman
- Plant Physiology Division, Bangladesh Rice Research Institute, Gazipur, Bangladesh
| | - Sudip Biswas
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Scott Schwartz
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | | | - Harkamal Walia
- Department of Agronomy and Horticulture, University of Nebraska, Lincoln, Nebraska 68583, USA
| | - Thomas E. Juenger
- Department of Integrative Biology and Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712, USA
| | - Zeba I. Seraj
- Plant Biotechnology Lab, Department of Biochemistry and Molecular Biology, University of Dhaka, Dhaka, 1000, Bangladesh
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Azhar N, Su N, Shabala L, Shabala S. Exogenously Applied 24-Epibrassinolide (EBL) Ameliorates Detrimental Effects of Salinity by Reducing K+ Efflux via Depolarization-Activated K+ Channels. PLANT & CELL PHYSIOLOGY 2017; 58:802-810. [PMID: 28340062 DOI: 10.1093/pcp/pcx026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 02/06/2017] [Indexed: 05/19/2023]
Abstract
This study has investigated mechanisms conferring beneficial effects of exogenous application of 24-epibrassinolides (EBL) on plant growth and performance under saline conditions. Barley seedlings treated with 0.25 mg l-1 EBL showed significant improvements in root hair length, shoot length, shoot fresh weight and relative water content when grown in the presence of 150 mM NaCl in the growth medium. In addition, EBL treatment significantly decreased the Na+ content in both shoots (by approximately 50%) and roots. Electrophysiological experiments revealed that pre-treatment with EBL for 1 and 24 h suppressed or completely prevented the NaCl-induced K+ leak in the elongation zone of barley roots, but did not affect root sensitivity to oxidative stress. Further experiments using Arabidopsis loss-of-function gork1-1 (lacking functional depolarization-activated outward-rectifying K+ channels in the root epidermal cells) and akt1 (lacking inward-rectifying K+ uptake channel) mutants showed that NaCl-induced K+ loss in the elongation zone of roots was reduced by EBL pre-treatment 50- to 100-fold in wild-type Col-0 and akt1, but only 10-fold in the gork1-1 mutant. At the same time, EBL treatment shifted vanadate-sensitive H+ flux towards net efflux. Taken together, these data indicate that exogenous application of EBL effectively improves plant salinity tolerance by prevention of K+ loss via regulating depolarization-activated K+ channels.
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Affiliation(s)
- Nazila Azhar
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
- Institute of Horticultural Sciences, University of Agriculture, Faisalabad, Pakistan
| | - Nana Su
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Lana Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania, Australia
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84
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Ma Q, Hu J, Zhou XR, Yuan HJ, Kumar T, Luan S, Wang SM. ZxAKT1 is essential for K + uptake and K + /Na + homeostasis in the succulent xerophyte Zygophyllum xanthoxylum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:48-60. [PMID: 28008679 DOI: 10.1111/tpj.13465] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 12/14/2016] [Accepted: 12/16/2016] [Indexed: 05/08/2023]
Abstract
The inward-rectifying K+ channel AKT1 constitutes an important pathway for K+ acquisition in plant roots. In glycophytes, excessive accumulation of Na+ is accompanied by K+ deficiency under salt stress. However, in the succulent xerophyte Zygophyllum xanthoxylum, which exhibits excellent adaptability to adverse environments, K+ concentration remains at a relatively constant level despite increased levels of Na+ under salinity and drought conditions. In this study, the contribution of ZxAKT1 to maintaining K+ and Na+ homeostasis in Z. xanthoxylum was investigated. Expression of ZxAKT1 rescued the K+ -uptake-defective phenotype of yeast strain CY162, suppressed the salt-sensitive phenotype of yeast strain G19, and complemented the low-K+ -sensitive phenotype of Arabidopsis akt1 mutant, indicating that ZxAKT1 functions as an inward-rectifying K+ channel. ZxAKT1 was predominantly expressed in roots, and was induced under high concentrations of either KCl or NaCl. By using RNA interference technique, we found that ZxAKT1-silenced plants exhibited stunted growth compared to wild-type Z. xanthoxylum. Further experiments showed that ZxAKT1-silenced plants exhibited a significant decline in net uptake of K+ and Na+ , resulting in decreased concentrations of K+ and Na+ , as compared to wild-type Z. xanthoxylum grown under 50 mm NaCl. Compared with wild-type, the expression levels of genes encoding several transporters/channels related to K+ /Na+ homeostasis, including ZxSKOR, ZxNHX, ZxSOS1 and ZxHKT1;1, were reduced in various tissues of a ZxAKT1-silenced line. These findings suggest that ZxAKT1 not only plays a crucial role in K+ uptake but also functions in modulating Na+ uptake and transport systems in Z. xanthoxylum, thereby affecting its normal growth.
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Affiliation(s)
- Qing Ma
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Jing Hu
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Xiang-Rui Zhou
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Hui-Jun Yuan
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Tanweer Kumar
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
| | - Sheng Luan
- Department of Plant and Microbial Biology, University of California at Berkeley, Berkeley, CA, 73072, USA
- NJU-NJFU Joint Institute for Plant Molecular Biology, College of Life Sciences, Nanjing University, Nanjing, 210093, China
| | - Suo-Min Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730020, China
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85
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Dassanayake M, Larkin JC. Making Plants Break a Sweat: the Structure, Function, and Evolution of Plant Salt Glands. FRONTIERS IN PLANT SCIENCE 2017; 8:406. [PMID: 28400779 PMCID: PMC5368257 DOI: 10.3389/fpls.2017.00406] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 03/09/2017] [Indexed: 05/25/2023]
Abstract
Salt stress is a complex trait that poses a grand challenge in developing new crops better adapted to saline environments. Some plants, called recretohalophytes, that have naturally evolved to secrete excess salts through salt glands, offer an underexplored genetic resource for examining how plant development, anatomy, and physiology integrate to prevent excess salt from building up to toxic levels in plant tissue. In this review we examine the structure and evolution of salt glands, salt gland-specific gene expression, and the possibility that all salt glands have originated via evolutionary modifications of trichomes. Salt secretion via salt glands is found in more than 50 species in 14 angiosperm families distributed in caryophyllales, asterids, rosids, and grasses. The salt glands of these distantly related clades can be grouped into four structural classes. Although salt glands appear to have originated independently at least 12 times, they share convergently evolved features that facilitate salt compartmentalization and excretion. We review the structural diversity and evolution of salt glands, major transporters and proteins associated with salt transport and secretion in halophytes, salt gland relevant gene expression regulation, and the prospect for using new genomic and transcriptomic tools in combination with information from model organisms to better understand how salt glands contribute to salt tolerance. Finally, we consider the prospects for using this knowledge to engineer salt glands to increase salt tolerance in model species, and ultimately in crops.
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Affiliation(s)
- Maheshi Dassanayake
- Department of Biological Sciences, Louisiana State University, Baton RougeLA, USA
| | - John C. Larkin
- Department of Biological Sciences, Louisiana State University, Baton RougeLA, USA
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86
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Percey WJ, McMinn A, Bose J, Breadmore MC, Guijt RM, Shabala S. Salinity effects on chloroplast PSII performance in glycophytes and halophytes. FUNCTIONAL PLANT BIOLOGY : FPB 2016; 43:1003-1015. [PMID: 32480522 DOI: 10.1071/fp16135] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Accepted: 06/12/2016] [Indexed: 06/11/2023]
Abstract
The effects of NaCl stress and K+ nutrition on photosynthetic parameters of isolated chloroplasts were investigated using PAM fluorescence. Intact mesophyll cells were able to maintain optimal photosynthetic performance when exposed to salinity for more than 24h whereas isolated chloroplasts showed declines in both the relative electron transport rate (rETR) and the maximal photochemical efficiency of PSII (Fv/Fm) within the first hour of treatment. The rETR was much more sensitive to salt stress compared with Fv/Fm, with 40% inhibition of rETR observed at apoplastic NaCl concentration as low as 20mM. In isolated chloroplasts, absolute K+ concentrations were more essential for the maintenance of the optimal photochemical performance (Fv/Fm values) rather than sodium concentrations per se. Chloroplasts from halophyte species of quinoa (Chenopodium quinoa Willd.) and pigface (Carpobrotus rosii (Haw.) Schwantes) showed less than 18% decline in Fv/Fm under salinity, whereas the Fv/Fm decline in chloroplasts from glycophyte pea (Pisum sativum L.) and bean (Vicia faba L.) species was much stronger (31 and 47% respectively). Vanadate (a P-type ATPase inhibitor) significantly reduced Fv/Fm in both control and salinity treated chloroplasts (by 7 and 25% respectively), whereas no significant effects of gadolinium (blocker of non-selective cation channels) were observed in salt-treated chloroplasts. Tetraethyl ammonium (TEA) (K+ channel inhibitor) and amiloride (inhibitor of the Na+/H+ antiporter) increased the Fv/Fm of salinity treated chloroplasts by 16 and 17% respectively. These results suggest that chloroplasts' ability to regulate ion transport across the envelope and thylakoid membranes play a critical role in leaf photosynthetic performance under salinity.
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Affiliation(s)
- William J Percey
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart 7001, Australia
| | - Andrew McMinn
- Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart 7001, Australia
| | - Jayakumar Bose
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart 7001, Australia
| | - Michael C Breadmore
- Australian Centre for Research on Separation Science (ACROSS) and School of Chemistry, University of Tasmania, Private Bag 75, Hobart 7001, Australia
| | - Rosanne M Guijt
- School of Medicine and Australian Centre for Research on Separation Science, University of Tasmania, Private Bag 34, Hobart 7001, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Private Bag 54, Hobart 7001, Australia
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87
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Takeno K. Stress-induced flowering: the third category of flowering response. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:4925-34. [PMID: 27382113 DOI: 10.1093/jxb/erw272] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The switch from vegetative growth to reproductive growth, i.e. flowering, is the critical event in a plant's life. Flowering is regulated either autonomously or by environmental factors; photoperiodic flowering, which is regulated by the duration of the day and night periods, and vernalization, which is regulated by low temperature, have been well studied. Additionally, it has become clear that stress also regulates flowering. Diverse stress factors can induce or accelerate flowering, or inhibit or delay it, in a wide range of plant species. This article focuses on the positive regulation of flowering via stress, i.e. the induction or acceleration of flowering in response to stress that is known as stress-induced flowering - a new category of flowering response. This review aims to clarify the concept of stress-induced flowering and to summarize the full range of characteristics of stress-induced flowering from a predominately physiological perspective.
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Affiliation(s)
- Kiyotoshi Takeno
- Department of Biology, Faculty of Science, Niigata University, Ikarashi, Niigata 950-2181, Japan
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88
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Chakraborty K, Bose J, Shabala L, Shabala S. Difference in root K+ retention ability and reduced sensitivity of K+-permeable channels to reactive oxygen species confer differential salt tolerance in three Brassica species. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:4611-25. [PMID: 27340231 PMCID: PMC4973732 DOI: 10.1093/jxb/erw236] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Brassica species are known to possess significant inter and intraspecies variability in salinity stress tolerance, but the cell-specific mechanisms conferring this difference remain elusive. In this work, the role and relative contribution of several key plasma membrane transporters to salinity stress tolerance were evaluated in three Brassica species (B. napus, B. juncea, and B. oleracea) using a range of electrophysiological assays. Initial root growth assay and viability staining revealed that B. napus was most tolerant amongst the three species, followed by B. juncea and B. oleracea At the mechanistic level, this difference was conferred by at least three complementary physiological mechanisms: (i) higher Na(+) extrusion ability from roots resulting from increased expression and activity of plasma membrane SOS1-like Na(+)/H(+) exchangers; (ii) better root K(+) retention ability resulting from stress-inducible activation of H(+)-ATPase and ability to maintain more negative membrane potential under saline conditions; and (iii) reduced sensitivity of B. napus root K(+)-permeable channels to reactive oxygen species (ROS). The last two mechanisms played the dominant role and conferred most of the differential salt sensitivity between species. Brassica napus plants were also more efficient in preventing the stress-induced increase in GORK transcript levels and up-regulation of expression of AKT1, HAK5, and HKT1 transporter genes. Taken together, our data provide the mechanistic explanation for differential salt stress sensitivity amongst these species and shed light on transcriptional and post-translational regulation of key ion transport systems involved in the maintenance of the root plasma membrane potential and cytosolic K/Na ratio as a key attribute for salt tolerance in Brassica species.
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Affiliation(s)
- Koushik Chakraborty
- Department of Plant Physiology, ICAR-Directorate of Groundnut Research, Junagadh, Gujarat-362 001, India School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia
| | - Jayakumar Bose
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia
| | - Lana Shabala
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia
| | - Sergey Shabala
- School of Land and Food and Tasmanian Institute for Agriculture, University of Tasmania, Hobart, Private Bag 94, Tas 7001, Australia
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89
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Wang F, Chen ZH, Liu X, Colmer TD, Zhou M, Shabala S. Tissue-specific root ion profiling reveals essential roles of the CAX and ACA calcium transport systems in response to hypoxia in Arabidopsis. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:3747-62. [PMID: 26889007 PMCID: PMC4896357 DOI: 10.1093/jxb/erw034] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Waterlogging is a major abiotic stress that limits the growth of plants. The crucial role of Ca(2+) as a second messenger in response to abiotic and biotic stimuli has been widely recognized in plants. However, the physiological and molecular mechanisms of Ca(2+) distribution within specific cell types in different root zones under hypoxia is poorly understood. In this work, whole-plant physiological and tissue-specific Ca(2+) changes were studied using several ACA (Ca(2+)-ATPase) and CAX (Ca(2+)/proton exchanger) knock-out Arabidopsis mutants subjected to waterlogging treatment. In the wild-type (WT) plants, several days of hypoxia decreased the expression of ACA8, CAX4, and CAX11 by 33% and 50% compared with the control. The hypoxic treatment also resulted in an up to 11-fold tissue-dependent increase in Ca(2+) accumulation in root tissues as revealed by confocal microscopy. The increase was much higher in stelar cells in the mature zone of Arabidopsis mutants with loss of function for ACA8, ACA11, CAX4, and CAX11 In addition, a significantly increased Ca(2+) concentration was found in the cytosol of stelar cells in the mature zone after hypoxic treatment. Three weeks of waterlogging resulted in dramatic loss of shoot biomass in cax11 plants (67% loss in shoot dry weight), while in the WT and other transport mutants this decline was only 14-22%. These results were also consistent with a decline in leaf chlorophyll fluorescence (F v/F m). It is suggested that CAX11 plays a key role in maintaining cytosolic Ca(2+) homeostasis and/or signalling in root cells under hypoxic conditions.
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Affiliation(s)
- Feifei Wang
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Zhong-Hua Chen
- School of Science and Health, Western Sydney University, Penrith NSW2751, Australia
| | - Xiaohui Liu
- School of Science and Health, Western Sydney University, Penrith NSW2751, Australia School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Timothy David Colmer
- School of Plant Biology and Institute of Agriculture, The University of Western Australia, Crawley, WA 6009, Australia
| | - Meixue Zhou
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Sergey Shabala
- School of Land and Food, University of Tasmania, Hobart, Tasmania 7001, Australia
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90
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Plant roots: new challenges in a changing world. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:991-993. [PMCID: PMC4753856 DOI: 10.1093/jxb/erw027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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