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Volumn 38, Issue 6, 2015, Pages 1011-1022

Genome-wide association mapping and biochemical markers reveal that seed ageing and longevity are intricately affected by genetic background and developmental and environmental conditions in barley

Author keywords

Accelerated seed ageing; Gene bank; Genotype; Glutathione; Seed deterioration; Seed longevity; Storage conditions; Stress

Indexed keywords

BARLEY; BIOMARKER; BREEDING; CONSERVATION; GENOME; GENOTYPE; GERMPLASM; LONGEVITY; NUTRIENT AVAILABILITY; SEED TREATMENT;

EID: 84928675457     PISSN: 01407791     EISSN: 13653040     Source Type: Journal    
DOI: 10.1111/pce.12474     Document Type: Article
Times cited : (93)

References (69)
  • 2
    • 3042850902 scopus 로고    scopus 로고
    • Active oxygen species and antioxidants in seed biology
    • Bailly C. (2004) Active oxygen species and antioxidants in seed biology. Seed Science Research 14, 93-107.
    • (2004) Seed Science Research , vol.14 , pp. 93-107
    • Bailly, C.1
  • 3
    • 80855139579 scopus 로고    scopus 로고
    • Detailed characterization of mechanical properties and molecular mobility within dry seed glasses: relevance to the physiology of dry biological systems
    • Ballesteros D. & Walters C. (2011) Detailed characterization of mechanical properties and molecular mobility within dry seed glasses: relevance to the physiology of dry biological systems. The Plant Journal 68, 607-619.
    • (2011) The Plant Journal , vol.68 , pp. 607-619
    • Ballesteros, D.1    Walters, C.2
  • 5
    • 79961154684 scopus 로고    scopus 로고
    • Mathematically combined half-cell reduction potentials of low-molecular-weight thiols as markers of seed ageing
    • Birtic S., Colville L., Pritchard H.W., Pearce S.R. & Kranner I. (2011) Mathematically combined half-cell reduction potentials of low-molecular-weight thiols as markers of seed ageing. Free Radical Research 45, 1093-1102.
    • (2011) Free Radical Research , vol.45 , pp. 1093-1102
    • Birtic, S.1    Colville, L.2    Pritchard, H.W.3    Pearce, S.R.4    Kranner, I.5
  • 7
    • 10744230800 scopus 로고    scopus 로고
    • Rapid induction of distinct stress responses after the release of singlet oxygen in Arabidopsis
    • Camp R.G.L.O.D., Przybyla D., Ochsenbein C., Laloi C., Kim C., Danon A. & Apel K. (2003) Rapid induction of distinct stress responses after the release of singlet oxygen in Arabidopsis. The Plant Cell 15, 2320-2332.
    • (2003) The Plant Cell , vol.15 , pp. 2320-2332
    • Camp, R.G.L.O.D.1    Przybyla, D.2    Ochsenbein, C.3    Laloi, C.4    Kim, C.5    Danon, A.6    Apel, K.7
  • 8
    • 0032522824 scopus 로고    scopus 로고
    • The control of maize spikelet meristem fate by theAPETALA2-like gene indeterminatespikelet1
    • Chuck G., Meeley R.B. & Hake S. (1998) The control of maize spikelet meristem fate by theAPETALA2-like gene indeterminatespikelet1. Genes & Development 12, 1145-1154.
    • (1998) Genes & Development , vol.12 , pp. 1145-1154
    • Chuck, G.1    Meeley, R.B.2    Hake, S.3
  • 9
    • 2442681968 scopus 로고    scopus 로고
    • Analysis of natural allelic variation of Arabidopsis seed germination and seed longevity traits between the accessions Landsberg erecta and Shakdara, using a new recombinant inbred line population
    • Clerkx E.J.M., El-Lithy M.E., Vierling E., Ruys G.J., Blankestijin-De Vries H., Groot S.P.C. & Koornneef M. (2004) Analysis of natural allelic variation of Arabidopsis seed germination and seed longevity traits between the accessions Landsberg erecta and Shakdara, using a new recombinant inbred line population. Plant Physiology 135, 432-443.
    • (2004) Plant Physiology , vol.135 , pp. 432-443
    • Clerkx, E.J.M.1    El-Lithy, M.E.2    Vierling, E.3    Ruys, G.J.4    Blankestijin-De Vries, H.5    Groot, S.P.C.6    Koornneef, M.7
  • 10
    • 77958561000 scopus 로고    scopus 로고
    • Desiccation tolerant plants as model systems to study redox regulation of protein thiols
    • Colville L. & Kranner I. (2010) Desiccation tolerant plants as model systems to study redox regulation of protein thiols. Plant Growth Regulation 62, 241-255.
    • (2010) Plant Growth Regulation , vol.62 , pp. 241-255
    • Colville, L.1    Kranner, I.2
  • 13
    • 77951114666 scopus 로고    scopus 로고
    • Tocochromanol functions in plants: antioxidation and beyond
    • Falk J. & Munné-Bosch S. (2010) Tocochromanol functions in plants: antioxidation and beyond. Journal of Experimental Botany 61, 1549-1566.
    • (2010) Journal of Experimental Botany , vol.61 , pp. 1549-1566
    • Falk, J.1    Munné-Bosch, S.2
  • 14
    • 0003437299 scopus 로고    scopus 로고
    • PHYLIP 3.69 (Phylogeny Inference Package)
    • Washington.
    • Felsenstein J. (2009) PHYLIP 3.69 (Phylogeny Inference Package), Washington.
    • (2009)
    • Felsenstein, J.1
  • 15
    • 84879965863 scopus 로고    scopus 로고
    • Evidence for the absence of enzymatic reactions in the glassy state. A case study of xanthophyll cycle pigments in the desiccation-tolerant moss Syntrichia ruralis
    • Fernández-Marín B., Kranner I., Sebastián M.S., Artetxe U., Laza J.M., Vilas J.L. & García-Plazaola J.I. (2013) Evidence for the absence of enzymatic reactions in the glassy state. A case study of xanthophyll cycle pigments in the desiccation-tolerant moss Syntrichia ruralis. Journal of Experimental Botany 64, 3033-3043.
    • (2013) Journal of Experimental Botany , vol.64 , pp. 3033-3043
    • Fernández-Marín, B.1    Kranner, I.2    Sebastián, M.S.3    Artetxe, U.4    Laza, J.M.5    Vilas, J.L.6    García-Plazaola, J.I.7
  • 16
    • 84855347955 scopus 로고    scopus 로고
    • Managing the cellular redox hub in photosynthetic organisms
    • Foyer C.H. & Noctor G. (2012) Managing the cellular redox hub in photosynthetic organisms. Plant, Cell & Environment 35, 199-201.
    • (2012) Plant, Cell & Environment , vol.35 , pp. 199-201
    • Foyer, C.H.1    Noctor, G.2
  • 20
    • 33751026169 scopus 로고    scopus 로고
    • Development and testing of 'on-farm' seed priming
    • Harris D. (2006) Development and testing of 'on-farm' seed priming. Advances in Agronomy 90, 129-178.
    • (2006) Advances in Agronomy , vol.90 , pp. 129-178
    • Harris, D.1
  • 21
    • 0344066300 scopus 로고    scopus 로고
    • Seed 1-cysteine peroxiredoxin antioxidants are not involved in dormancy, but contribute to inhibition of germination during stress
    • Haslekas C., Viken M.K., Grini P.E., Nygaard V., Nordgard S.H., Meza T.J. & Aalen R.B. (2003) Seed 1-cysteine peroxiredoxin antioxidants are not involved in dormancy, but contribute to inhibition of germination during stress. Plant Physiology 133, 1148-1157.
    • (2003) Plant Physiology , vol.133 , pp. 1148-1157
    • Haslekas, C.1    Viken, M.K.2    Grini, P.E.3    Nygaard, V.4    Nordgard, S.H.5    Meza, T.J.6    Aalen, R.B.7
  • 22
    • 56849103943 scopus 로고    scopus 로고
    • The use of non-saturated lithium chloride solutions for experimental control of seed water content
    • Hay F.R., Adams J., Manger K. & Probert R. (2008) The use of non-saturated lithium chloride solutions for experimental control of seed water content. Seed Science and Technology 36, 737-746.
    • (2008) Seed Science and Technology , vol.36 , pp. 737-746
    • Hay, F.R.1    Adams, J.2    Manger, K.3    Probert, R.4
  • 23
    • 84867740272 scopus 로고    scopus 로고
    • Grain dormancy QTL identified in a doubled haploid barley population derived from two non-dormant parents
    • Hickey L.T., Lawson W., Arief V.N., Fox G., Franckowiak J. & Dieters M.J. (2012) Grain dormancy QTL identified in a doubled haploid barley population derived from two non-dormant parents. Euphytica 188, 113-122.
    • (2012) Euphytica , vol.188 , pp. 113-122
    • Hickey, L.T.1    Lawson, W.2    Arief, V.N.3    Fox, G.4    Franckowiak, J.5    Dieters, M.J.6
  • 24
    • 44649092841 scopus 로고    scopus 로고
    • Molecular networks regulating Arabidopsis seed maturation, after-ripening, dormancy and germination
    • Holdsworth M.J., Bentsink L. & Soppe W.J.J. (2008) Molecular networks regulating Arabidopsis seed maturation, after-ripening, dormancy and germination. New Phytologist 179, 33-54.
    • (2008) New Phytologist , vol.179 , pp. 33-54
    • Holdsworth, M.J.1    Bentsink, L.2    Soppe, W.J.J.3
  • 25
    • 84255174082 scopus 로고    scopus 로고
    • International Rules for Seed Testing.
    • Bassersdorf, Switzerland.
    • ISTA (2014) International Rules for Seed Testing. International Seed Testing Association, Bassersdorf, Switzerland.
    • (2014) International Seed Testing Association
  • 26
    • 34248207000 scopus 로고    scopus 로고
    • A novel transcriptional cascade regulating expression of heat stress proteins during seed development of Arabidopsis
    • Kotak S., Vierling E., Baumlein H. & von Koskull-Doring P. (2007) A novel transcriptional cascade regulating expression of heat stress proteins during seed development of Arabidopsis. The Plant Cell 19, 182-195.
    • (2007) The Plant Cell , vol.19 , pp. 182-195
    • Kotak, S.1    Vierling, E.2    Baumlein, H.3    von Koskull-Doring, P.4
  • 27
    • 0030024593 scopus 로고    scopus 로고
    • Determination of glutathione and glutathione disulphide in lichens: a comparison of frequently used methods
    • Kranner I. & Grill D. (1996) Determination of glutathione and glutathione disulphide in lichens: a comparison of frequently used methods. Phytochemical Analysis 7, 24-28.
    • (1996) Phytochemical Analysis , vol.7 , pp. 24-28
    • Kranner, I.1    Grill, D.2
  • 28
    • 33745322651 scopus 로고    scopus 로고
    • Glutathione half-cell reduction potential: a universal stress marker and modulator of programmed cell death?
    • Kranner I., Birtic S., Anderson K.M. & Pritchard H.W. (2006) Glutathione half-cell reduction potential: a universal stress marker and modulator of programmed cell death? Free Radical Biology and Medicine 40, 2155-2165.
    • (2006) Free Radical Biology and Medicine , vol.40 , pp. 2155-2165
    • Kranner, I.1    Birtic, S.2    Anderson, K.M.3    Pritchard, H.W.4
  • 30
    • 77958583033 scopus 로고    scopus 로고
    • What is stress? Concepts, definitions and applications in seed science
    • Kranner I., Minibayeva F.V., Beckett R.P. & Seal C.E. (2010b) What is stress? Concepts, definitions and applications in seed science. New Phytologist 188, 655-673.
    • (2010) New Phytologist , vol.188 , pp. 655-673
    • Kranner, I.1    Minibayeva, F.V.2    Beckett, R.P.3    Seal, C.E.4
  • 31
    • 78650312287 scopus 로고    scopus 로고
    • Inter-nucleosomal DNA fragmentation and loss of RNA integrity during seed ageing
    • Kranner I., Chen H., Pritchard H., Pearce S. & Birtić S. (2011) Inter-nucleosomal DNA fragmentation and loss of RNA integrity during seed ageing. Plant Growth Regulation 63, 63-72.
    • (2011) Plant Growth Regulation , vol.63 , pp. 63-72
    • Kranner, I.1    Chen, H.2    Pritchard, H.3    Pearce, S.4    Birtić, S.5
  • 34
    • 0030964283 scopus 로고    scopus 로고
    • Mapping quantitative trait loci for salt tolerance at germination and the seedling stage in barley (Hordeum vulgare L)
    • Mano Y. & Takeda K. (1997) Mapping quantitative trait loci for salt tolerance at germination and the seedling stage in barley (Hordeum vulgare L). Euphytica 94, 263-272.
    • (1997) Euphytica , vol.94 , pp. 263-272
    • Mano, Y.1    Takeda, K.2
  • 36
    • 0036728244 scopus 로고    scopus 로고
    • Oxidative stress, antioxidants and stress tolerance
    • Mittler R. (2002) Oxidative stress, antioxidants and stress tolerance. Trends in Plant Science 7, 405-410.
    • (2002) Trends in Plant Science , vol.7 , pp. 405-410
    • Mittler, R.1
  • 37
    • 0346665955 scopus 로고    scopus 로고
    • Mapping quantitative trait loci controlling seed longevity in rice (Oryza sativa L.)
    • Miura K., Lin S.Y., Yano M. & Nagamine T. (2002) Mapping quantitative trait loci controlling seed longevity in rice (Oryza sativa L.). Theoretical and Applied Genetics 104, 981-986.
    • (2002) Theoretical and Applied Genetics , vol.104 , pp. 981-986
    • Miura, K.1    Lin, S.Y.2    Yano, M.3    Nagamine, T.4
  • 38
    • 77952485837 scopus 로고    scopus 로고
    • The longevity of crop seeds stored under ambient conditions
    • Nagel M. & Börner A. (2010) The longevity of crop seeds stored under ambient conditions. Seed Science Research 20, 1-12.
    • (2010) Seed Science Research , vol.20 , pp. 1-12
    • Nagel, M.1    Börner, A.2
  • 40
    • 84870836905 scopus 로고    scopus 로고
    • Natural variation for seed longevity and seed dormancy are negatively correlated in Arabidopsis
    • Nguyen T.P., Keizer P., van Eeuwijk F., Smeekens S. & Bentsink L. (2012) Natural variation for seed longevity and seed dormancy are negatively correlated in Arabidopsis. Plant Physiology 160, 2083-2092.
    • (2012) Plant Physiology , vol.160 , pp. 2083-2092
    • Nguyen, T.P.1    Keizer, P.2    van Eeuwijk, F.3    Smeekens, S.4    Bentsink, L.5
  • 42
    • 70450222507 scopus 로고    scopus 로고
    • Effects of APETALA2 on embryo, endosperm, and seed coat development determine seed size in Arabidopsis
    • Ohto M.-A., Floyd S., Fischer R., Goldberg R. & Harada J. (2009) Effects of APETALA2 on embryo, endosperm, and seed coat development determine seed size in Arabidopsis. Sexual Plant Reproduction 22, 277-289.
    • (2009) Sexual Plant Reproduction , vol.22 , pp. 277-289
    • Ohto, M.-A.1    Floyd, S.2    Fischer, R.3    Goldberg, R.4    Harada, J.5
  • 45
    • 0034118493 scopus 로고    scopus 로고
    • Inference of population structure using multilocus genotype data
    • Pritchard J.K., Stephens M. & Donnelly P.J. (2000) Inference of population structure using multilocus genotype data. Genetics 155, 945-959.
    • (2000) Genetics , vol.155 , pp. 945-959
    • Pritchard, J.K.1    Stephens, M.2    Donnelly, P.J.3
  • 46
    • 52749084341 scopus 로고    scopus 로고
    • Seed longevity: survival and maintenance of high germination ability of dry seeds
    • Rajjou L. & Debeaujon I. (2008) Seed longevity: survival and maintenance of high germination ability of dry seeds. Comptes Rendus Biologies 331, 796-805.
    • (2008) Comptes Rendus Biologies , vol.331 , pp. 796-805
    • Rajjou, L.1    Debeaujon, I.2
  • 47
    • 16244392436 scopus 로고    scopus 로고
    • Decrease in beech (Fagus sylvatica) seed viability caused by temperature and humidity conditions as related to membrane damage and lipid composition
    • Ratajczak E. & Pukacka S. (2005) Decrease in beech (Fagus sylvatica) seed viability caused by temperature and humidity conditions as related to membrane damage and lipid composition. Acta Physiologiae Plantarum 27, 3-12.
    • (2005) Acta Physiologiae Plantarum , vol.27 , pp. 3-12
    • Ratajczak, E.1    Pukacka, S.2
  • 48
    • 0001179177 scopus 로고
    • Predicting the storage life of seeds
    • Roberts E.H. (1973) Predicting the storage life of seeds. Seed Science and Technology 1, 499-514.
    • (1973) Seed Science and Technology , vol.1 , pp. 499-514
    • Roberts, E.H.1
  • 49
    • 2942672961 scopus 로고    scopus 로고
    • Vitamin E is essential for seed longevity, and for preventing lipid peroxidation during germination
    • Sattler S.E., Gilliland L.U., Magallanes-Lundback M., Pollard M. & DellaPenna D. (2004) Vitamin E is essential for seed longevity, and for preventing lipid peroxidation during germination. The Plant Cell 16, 1419-1432.
    • (2004) The Plant Cell , vol.16 , pp. 1419-1432
    • Sattler, S.E.1    Gilliland, L.U.2    Magallanes-Lundback, M.3    Pollard, M.4    DellaPenna, D.5
  • 50
    • 0035371184 scopus 로고    scopus 로고
    • Redox environment of the cell as viewed through the redox state of the glutathione disulfide/glutathione couple
    • Schafer F.Q. & Buettner G.R. (2001) Redox environment of the cell as viewed through the redox state of the glutathione disulfide/glutathione couple. Free Radical Biology and Medicine 30, 1191-1212.
    • (2001) Free Radical Biology and Medicine , vol.30 , pp. 1191-1212
    • Schafer, F.Q.1    Buettner, G.R.2
  • 51
    • 77952547103 scopus 로고    scopus 로고
    • Glutathione half-cell reduction potential and α-tocopherol as viability markers during the prolonged storage of Suaeda maritima seeds
    • Seal C.E., Zammit R., Scott P., Flowers T.J. & Kranner I. (2010) Glutathione half-cell reduction potential and α-tocopherol as viability markers during the prolonged storage of Suaeda maritima seeds. Seed Science Research 20, 47-53.
    • (2010) Seed Science Research , vol.20 , pp. 47-53
    • Seal, C.E.1    Zammit, R.2    Scott, P.3    Flowers, T.J.4    Kranner, I.5
  • 52
    • 32844460538 scopus 로고
    • Amino acid composition and nitrogen-to-protein conversion factors for animal and plant foods
    • Sosulski F.W. & Imafidon G.I. (1990) Amino acid composition and nitrogen-to-protein conversion factors for animal and plant foods. Journal of Agricultural and Food Chemistry 38, 1351-1356.
    • (1990) Journal of Agricultural and Food Chemistry , vol.38 , pp. 1351-1356
    • Sosulski, F.W.1    Imafidon, G.I.2
  • 53
    • 0029189529 scopus 로고
    • Germination of 110-year-old cereal and weed seeds, the Vienna sample of 1877. Verification of effective ultra-dry storage at ambient temperature
    • Steiner A.M. & Ruckenbauer P. (1995) Germination of 110-year-old cereal and weed seeds, the Vienna sample of 1877. Verification of effective ultra-dry storage at ambient temperature. Seed Science Research 5, 195-199.
    • (1995) Seed Science Research , vol.5 , pp. 195-199
    • Steiner, A.M.1    Ruckenbauer, P.2
  • 54
    • 61349178533 scopus 로고    scopus 로고
    • Ribonuclease H: molecular diversities, substrate binding domains, and catalytic mechanism of the prokaryotic enzymes
    • Tadokoro T. & Kanaya S. (2009) Ribonuclease H: molecular diversities, substrate binding domains, and catalytic mechanism of the prokaryotic enzymes. FEBS Journal 276, 1482-1493.
    • (2009) FEBS Journal , vol.276 , pp. 1482-1493
    • Tadokoro, T.1    Kanaya, S.2
  • 55
    • 26944451275 scopus 로고    scopus 로고
    • Overexpression of the pepper transcription factor CaPF1 in transgenic virginia pine (Pinus Virginiana Mill.) confers multiple stress tolerance and enhances organ growth
    • Tang W., Charles T. & Newton R. (2005) Overexpression of the pepper transcription factor CaPF1 in transgenic virginia pine (Pinus Virginiana Mill.) confers multiple stress tolerance and enhances organ growth. Plant Molecular Biology 59, 603-617.
    • (2005) Plant Molecular Biology , vol.59 , pp. 603-617
    • Tang, W.1    Charles, T.2    Newton, R.3
  • 56
    • 84928655941 scopus 로고    scopus 로고
    • A computer program for statistical analysis of plant breeding experiments, Institute of Plant Breeding, Seed Science and Population Genetics, University of Hohenheim, Stuttgart, Germany.
    • Utz H.F. (2011) PlabStat (version 3A). A computer program for statistical analysis of plant breeding experiments, Institute of Plant Breeding, Seed Science and Population Genetics, University of Hohenheim, Stuttgart, Germany.
    • (2011)
    • Utz, H.F.1
  • 60
    • 30744432706 scopus 로고    scopus 로고
    • Dying while dry: kinetics and mechanisms of deterioration in desiccated organisms
    • Walters C., Hill L.M. & Wheeler L.J. (2005a) Dying while dry: kinetics and mechanisms of deterioration in desiccated organisms. Integrative and Comparative Biology 45, 751-758.
    • (2005) Integrative and Comparative Biology , vol.45 , pp. 751-758
    • Walters, C.1    Hill, L.M.2    Wheeler, L.J.3
  • 61
    • 15544379339 scopus 로고    scopus 로고
    • Longevity of seeds stored in a genebank: species characteristics
    • Walters C., Wheeler L.M. & Grotenhuis J.M. (2005b) Longevity of seeds stored in a genebank: species characteristics. Seed Science Research 15, 1-20.
    • (2005) Seed Science Research , vol.15 , pp. 1-20
    • Walters, C.1    Wheeler, L.M.2    Grotenhuis, J.M.3
  • 62
    • 78049256276 scopus 로고    scopus 로고
    • Structural mechanics of seed deterioration: standing the test of time
    • Walters C., Ballesteros D. & Vertucci V.A. (2010) Structural mechanics of seed deterioration: standing the test of time. Plant Science 179, 565-573.
    • (2010) Plant Science , vol.179 , pp. 565-573
    • Walters, C.1    Ballesteros, D.2    Vertucci, V.A.3
  • 66
    • 33748700045 scopus 로고    scopus 로고
    • A high-density consensus map of barley linking DArT markers to SSR, RFLP and STS loci and agricultural traits
    • Wenzl P., Li H.B., Carling J., Zhou M.X., Raman H., Paul E. & Kilian A. (2006) A high-density consensus map of barley linking DArT markers to SSR, RFLP and STS loci and agricultural traits. BMC Genomics 7, 206.
    • (2006) BMC Genomics , vol.7 , pp. 206
    • Wenzl, P.1    Li, H.B.2    Carling, J.3    Zhou, M.X.4    Raman, H.5    Paul, E.6    Kilian, A.7
  • 67
    • 57749115787 scopus 로고    scopus 로고
    • Transcriptional modulation of ethylene response factor protein JERF3 in the oxidative stress response enhances tolerance of tobacco seedlings to salt, drought, and freezing
    • Wu L., Zhang Z., Zhang H., Wang X.-C. & Huang R. (2008) Transcriptional modulation of ethylene response factor protein JERF3 in the oxidative stress response enhances tolerance of tobacco seedlings to salt, drought, and freezing. Plant Physiology 148, 1953-1963.
    • (2008) Plant Physiology , vol.148 , pp. 1953-1963
    • Wu, L.1    Zhang, Z.2    Zhang, H.3    Wang, X.-C.4    Huang, R.5
  • 68
    • 31744440502 scopus 로고    scopus 로고
    • A unified mixed-model method for association mapping that accounts for multiple levels of relatedness
    • Yu J., Pressoir G., Briggs W.H., Vroh Bi I., Yamasaki M., Doebley J.F. & Buckler E.S. (2006) A unified mixed-model method for association mapping that accounts for multiple levels of relatedness. Nature Genetics 38, 203-208.
    • (2006) Nature Genetics , vol.38 , pp. 203-208
    • Yu, J.1    Pressoir, G.2    Briggs, W.H.3    Vroh Bi, I.4    Yamasaki, M.5    Doebley, J.F.6    Buckler, E.S.7
  • 69


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