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Volumn 85, Issue 1, 2004, Pages 16-27

Plant hormones regulate fast shoot elongation under water: From genes to communities

Author keywords

Abscisic acid; Auxin; Cost benefit analysis; Elongation growth; Ethylene; Flooding duration; Gibberellin; Plant species distribution; Rumex; Soil dehydration; Submergence; Upscaling

Indexed keywords

ADAPTATION; DROUGHT; GROWTH; GROWTH REGULATOR; HORMONE; PHYSIOLOGY;

EID: 1342290157     PISSN: 00129658     EISSN: None     Source Type: Journal    
DOI: 10.1890/02-740     Document Type: Review
Times cited : (248)

References (65)
  • 2
    • 0029911083 scopus 로고    scopus 로고
    • Ethylene biosynthesis and accumulation under drained and submerged conditions: A comparative study of two Rumex species
    • Banga, M., E. J. Slaa, C. W. P. M. Blom, and L. A. C. J. Voesenek. 1996. Ethylene biosynthesis and accumulation under drained and submerged conditions: a comparative study of two Rumex species. Plant Physiology 112:229-237.
    • (1996) Plant Physiology , vol.112 , pp. 229-237
    • Banga, M.1    Slaa, E.J.2    Blom, C.W.P.M.3    Voesenek, L.A.C.J.4
  • 5
    • 85129798855 scopus 로고    scopus 로고
    • Adaptive mechanisms of plants occurring in wetland gradients
    • G. Mulamoottil, B. G. Warner, and E. A. McBean, editors. CRC Press, Boca Raton, Florida, USA
    • Blom, C. W. P. M., H. M. van de Steeg, and L. A. C. J. Voesenek. 1996. Adaptive mechanisms of plants occurring in wetland gradients. Pages 91-112 in G. Mulamoottil, B. G. Warner, and E. A. McBean, editors. Wetlands: environmental gradients, boundaries and buffers. CRC Press, Boca Raton, Florida, USA.
    • (1996) Wetlands: Environmental Gradients, Boundaries and Buffers , pp. 91-112
    • Blom, C.W.P.M.1    Van De Steeg, H.M.2    Voesenek, L.A.C.J.3
  • 8
    • 0037237630 scopus 로고    scopus 로고
    • Long-distance transport of gases in plants: A perspective on internal aeration and radial oxygen loss from roots
    • Colmer, T. D. 2003. Long-distance transport of gases in plants: a perspective on internal aeration and radial oxygen loss from roots. Plant, Cell and Environment 26:17-36.
    • (2003) Plant, Cell and Environment , vol.26 , pp. 17-36
    • Colmer, T.D.1
  • 9
    • 0031824369 scopus 로고    scopus 로고
    • The barrier to radial oxygen loss from roots of rice (Oryza sativa L.) is induced by growth in stagnant solution
    • Colmer, T. D., M. R. Gibberd, A. Wiengweera, and T. K. Tinh. 1998. The barrier to radial oxygen loss from roots of rice (Oryza sativa L.) is induced by growth in stagnant solution. Journal of Experimental Botany 49:1431-1436.
    • (1998) Journal of Experimental Botany , vol.49 , pp. 1431-1436
    • Colmer, T.D.1    Gibberd, M.R.2    Wiengweera, A.3    Tinh, T.K.4
  • 12
    • 0345504891 scopus 로고    scopus 로고
    • Crosstalk in plant cell signaling: Structure and function of the genetic network
    • Genoud, T., and J. P. Metraux. 1999. Crosstalk in plant cell signaling: structure and function of the genetic network. Trends in Plant Science 4:503-507.
    • (1999) Trends in Plant Science , vol.4 , pp. 503-507
    • Genoud, T.1    Metraux, J.P.2
  • 13
    • 0034865343 scopus 로고    scopus 로고
    • Numeric simulation of plant signaling networks
    • Genoud, T., M. B. T. Santa Cruz, and J. P. Metraux. 2001. Numeric simulation of plant signaling networks. Plant Physiology 126:1430-1437.
    • (2001) Plant Physiology , vol.126 , pp. 1430-1437
    • Genoud, T.1    Santa Cruz, M.B.T.2    Metraux, J.P.3
  • 16
    • 0343315188 scopus 로고
    • Detrended correspondence analysis: An improved ordination technique
    • Hill, M. O., and H. G. Gauch. 1980. Detrended correspondence analysis: an improved ordination technique. Vegetatio 42:47-58.
    • (1980) Vegetatio , vol.42 , pp. 47-58
    • Hill, M.O.1    Gauch, H.G.2
  • 17
    • 0000875888 scopus 로고
    • On the role of abscisic acid and gibberellin in the regulation of growth in rice
    • Hoffmann-Benning, S., and H. Kende. 1992. On the role of abscisic acid and gibberellin in the regulation of growth in rice. Plant Physiology 99:1156-1161.
    • (1992) Plant Physiology , vol.99 , pp. 1156-1161
    • Hoffmann-Benning, S.1    Kende, H.2
  • 18
    • 0003190083 scopus 로고
    • The effect of ethylene and other regulators on coleoptile growth of rice under anoxia
    • Horton, R. F. 1991. The effect of ethylene and other regulators on coleoptile growth of rice under anoxia. Plant Science 79:57-62.
    • (1991) Plant Science , vol.79 , pp. 57-62
    • Horton, R.F.1
  • 19
    • 0032563147 scopus 로고    scopus 로고
    • Ethylene responses are negatively regulated by a receptor gene family in Arabidopsis thaliana
    • Hua, J., and E. M. Meyerowitz. 1998. Ethylene responses are negatively regulated by a receptor gene family in Arabidopsis thaliana. Cell 94:261-271.
    • (1998) Cell , vol.94 , pp. 261-271
    • Hua, J.1    Meyerowitz, E.M.2
  • 20
    • 0009385460 scopus 로고
    • Ethylene and the responses of plants to excess water in their environment: A review
    • J. A. Roberts and G. A. Tucker, editors. Butterworths, London, UK
    • Jackson, M. B. 1985. Ethylene and the responses of plants to excess water in their environment: A review. Pages 241-265 in J. A. Roberts and G. A. Tucker, editors. Ethylene and plant development. Butterworths, London, UK.
    • (1985) Ethylene and Plant Development , pp. 241-265
    • Jackson, M.B.1
  • 21
    • 0033039942 scopus 로고    scopus 로고
    • Formation of aerenchyma and the process of plant ventilation in relation to soil flooding and submergence
    • Jackson, M. B., and W. Armstrong. 1999. Formation of aerenchyma and the process of plant ventilation in relation to soil flooding and submergence. Plant Biology 1:274-287.
    • (1999) Plant Biology , vol.1 , pp. 274-287
    • Jackson, M.B.1    Armstrong, W.2
  • 22
    • 0001726586 scopus 로고    scopus 로고
    • Deepwater rice: A model plant to study stem elongation
    • Kende, H., E. v.d. Knaap, and H.-T. Cho. 1998. Deepwater rice: a model plant to study stem elongation. Plant Physiology 118:1105-1110.
    • (1998) Plant Physiology , vol.118 , pp. 1105-1110
    • Kende, H.1    Knaap, E.V.D.2    Cho, H.-T.3
  • 23
    • 0002752594 scopus 로고    scopus 로고
    • Abscisic acid inhibits shoot elongation of Scirpus mucronatus
    • Lee, T. M., Y. J. Shieh, and C. H. Chou. 1996. Abscisic acid inhibits shoot elongation of Scirpus mucronatus. Physiologia Plantarum 97:1-4.
    • (1996) Physiologia Plantarum , vol.97 , pp. 1-4
    • Lee, T.M.1    Shieh, Y.J.2    Chou, C.H.3
  • 24
    • 0035543408 scopus 로고    scopus 로고
    • Sites and homeostatic control of auxin biosynthesis in Arabidopsis during vegetative growth
    • Ljung, K., R. P. Bhalerao, and G. Sandberg. 2001. Sites and homeostatic control of auxin biosynthesis in Arabidopsis during vegetative growth. Plant Journal 28:465-474.
    • (2001) Plant Journal , vol.28 , pp. 465-474
    • Ljung, K.1    Bhalerao, R.P.2    Sandberg, G.3
  • 25
    • 0141712607 scopus 로고
    • Wetlands
    • M. B. Jackson, D. D. Davies, and H. Lambers, editors. SPB Academic Publishing, The Hague, The Netherlands
    • Maltby, E. 1991. Wetlands. Pages 3-21 in M. B. Jackson, D. D. Davies, and H. Lambers, editors. Plant life under oxygen deprivation. SPB Academic Publishing, The Hague, The Netherlands.
    • (1991) Plant Life under Oxygen Deprivation , pp. 3-21
    • Maltby, E.1
  • 26
    • 0021038965 scopus 로고
    • Plant strategies in relation to elevation and light in floodplain herbs
    • Menges, E. S., and D. M. Waller. 1983. Plant strategies in relation to elevation and light in floodplain herbs. American Naturalist 122:454-473.
    • (1983) American Naturalist , vol.122 , pp. 454-473
    • Menges, E.S.1    Waller, D.M.2
  • 27
    • 0035212396 scopus 로고    scopus 로고
    • Polar auxin transport: Controlling where and how much
    • Muday, G. K., and A. deLong. 2001. Polar auxin transport: controlling where and how much. Trends in Plant Science 6:535-542.
    • (2001) Trends in Plant Science , vol.6 , pp. 535-542
    • Muday, G.K.1    DeLong, A.2
  • 28
    • 0002838117 scopus 로고
    • Callitriche stem elongation is controlled by ethylene and gibberellin
    • Musgrave, A., M. B. Jackson, and E. Ling. 1972. Callitriche stem elongation is controlled by ethylene and gibberellin. Nature 238:93-96.
    • (1972) Nature , vol.238 , pp. 93-96
    • Musgrave, A.1    Jackson, M.B.2    Ling, E.3
  • 29
    • 0032763447 scopus 로고    scopus 로고
    • Resistance to complete submergence in Rumex species with different life histories: The influence of plant size and light
    • Nabben, R. H. M., C. W. P. M. Blom, and L. A. C. J. Voesenek. 1999. Resistance to complete submergence in Rumex species with different life histories: the influence of plant size and light. New Phytologist 144:313-321.
    • (1999) New Phytologist , vol.144 , pp. 313-321
    • Nabben, R.H.M.1    Blom, C.W.P.M.2    Voesenek, L.A.C.J.3
  • 31
    • 0027130342 scopus 로고
    • Plant responses to anaerobiosis
    • Perata, P., and A. Alpi. 1993. Plant responses to anaerobiosis. Plant Science 93:1-17.
    • (1993) Plant Science , vol.93 , pp. 1-17
    • Perata, P.1    Alpi, A.2
  • 32
    • 0002460723 scopus 로고
    • Ethylene and growth control in amphibious plants
    • R. M. M. Crawford, editor. Blackwell Scientific Publications, Oxford, UK
    • Ridge, I. 1987. Ethylene and growth control in amphibious plants. Pages 53-76 in R. M. M. Crawford, editor. Plant life in aquatic and amphibious habitats. Blackwell Scientific Publications, Oxford, UK.
    • (1987) Plant Life in Aquatic and Amphibious Habitats , pp. 53-76
    • Ridge, I.1
  • 33
    • 0033780313 scopus 로고    scopus 로고
    • The role of oxygen in submergence-induced petiole elongation in Rumex palustris: in situ measurements of oxygen in petioles of intact plants using micro-electrodes
    • Rijnders, J. G. H. M., W. Armstrong, M. J. Darwent, C. W. P. M. Blom, and L. A. C. J. Voesenek. 2000. The role of oxygen in submergence-induced petiole elongation in Rumex palustris: in situ measurements of oxygen in petioles of intact plants using micro-electrodes. New Phytologist 147:497-504.
    • (2000) New Phytologist , vol.147 , pp. 497-504
    • Rijnders, J.G.H.M.1    Armstrong, W.2    Darwent, M.J.3    Blom, C.W.P.M.4    Voesenek, L.A.C.J.5
  • 34
    • 0001496561 scopus 로고    scopus 로고
    • The contrasting role of auxin in submergence-induced petiole elongation in two species from frequently flooded wetlands
    • Rijnders, J. G. H. M., G. W. M. Barendse, C. W. P. M. Blom, and L. A. C. J. Voesenek. 1996. The contrasting role of auxin in submergence-induced petiole elongation in two species from frequently flooded wetlands. Physiologia Plantarum 96:467-473.
    • (1996) Physiologia Plantarum , vol.96 , pp. 467-473
    • Rijnders, J.G.H.M.1    Barendse, G.W.M.2    Blom, C.W.P.M.3    Voesenek, L.A.C.J.4
  • 35
    • 0030773920 scopus 로고    scopus 로고
    • Ethylene enhances gibberellin levels and petiole sensitivity in flooding-tolerant Rumex palustris but not in flooding-intolerant R. acetosa
    • Rijnders, J. G. H. M., Y.-Y. Yang, Y. Kamiya, N. Takahashi, G. W. M. Barendse, C. W. P. M. Blom, and L. A. C. J. Voesenek. 1997. Ethylene enhances gibberellin levels and petiole sensitivity in flooding-tolerant Rumex palustris but not in flooding-intolerant R. acetosa. Planta 203:20-25.
    • (1997) Planta , vol.203 , pp. 20-25
    • Rijnders, J.G.H.M.1    Yang, Y.-Y.2    Kamiya, Y.3    Takahashi, N.4    Barendse, G.W.M.5    Blom, C.W.P.M.6    Voesenek, L.A.C.J.7
  • 36
    • 0031769611 scopus 로고    scopus 로고
    • Gibberellins: Regulating genes and germination
    • Ritchie, S., and S. Gilroy. 1998. Gibberellins: regulating genes and germination. New Phytologist 140:363-383.
    • (1998) New Phytologist , vol.140 , pp. 363-383
    • Ritchie, S.1    Gilroy, S.2
  • 37
    • 0000805528 scopus 로고    scopus 로고
    • The response of plants to oxygen deprivation: Role of enzyme induction in the improvement of tolerance to anoxia
    • H. R. Lerner, editor. Marcel Dekker, New York, New York, USA
    • Saglio, P., V Germain, and B. Ricard. 1999. The response of plants to oxygen deprivation: role of enzyme induction in the improvement of tolerance to anoxia. Pages 373-393 in H. R. Lerner, editor. Plant responses to environmental stresses: from phytohormones to genome reorganization. Marcel Dekker, New York, New York, USA.
    • (1999) Plant Responses to Environmental Stresses: From Phytohormones to Genome Reorganization , pp. 373-393
    • Saglio, P.1    Germain, V.2    Ricard, B.3
  • 38
    • 0032816011 scopus 로고    scopus 로고
    • Manipulative approaches to testing adaptive plasticity, phytochrome-mediated shade-avoidance responses in plants
    • Schmitt, J., S. A. Dudley, and M. Pigliucci. 1999. Manipulative approaches to testing adaptive plasticity, phytochrome-mediated shade-avoidance responses in plants. American Naturalist 154:S43-S54.
    • (1999) American Naturalist , vol.154
    • Schmitt, J.1    Dudley, S.A.2    Pigliucci, M.3
  • 40
    • 0030452599 scopus 로고    scopus 로고
    • The beneficial effect of reduced elongation growth on submergence tolerance of rice
    • Setter, T. L., and E. V. Laureles. 1996. The beneficial effect of reduced elongation growth on submergence tolerance of rice. Journal of Experimental Botany 47:1551-1559.
    • (1996) Journal of Experimental Botany , vol.47 , pp. 1551-1559
    • Setter, T.L.1    Laureles, E.V.2
  • 42
    • 0002162618 scopus 로고
    • Antioxidant systems and plant response to the environment
    • N. Smirnoff, editor. Bios Scientific Publishing, Oxford, UK
    • Smirnoff, N. 1995. Antioxidant systems and plant response to the environment. Pages 217-243 in N. Smirnoff, editor. Environment and plant metabolism. Flexibility and acclimation. Bios Scientific Publishing, Oxford, UK.
    • (1995) Environment and Plant Metabolism. Flexibility and Acclimation , pp. 217-243
    • Smirnoff, N.1
  • 43
    • 0034609795 scopus 로고    scopus 로고
    • Phytochromes and light signal perception by plants - An emerging synthesis
    • Smith, H. 2000. Phytochromes and light signal perception by plants - an emerging synthesis. Nature 407:585-591.
    • (2000) Nature , vol.407 , pp. 585-591
    • Smith, H.1
  • 44
    • 0024199182 scopus 로고
    • Inundation and the distribution of plant communities on dutch river dikes
    • Sykora, K. V., E. Schepers, and F. van der Zee. 1988. Inundation and the distribution of plant communities on dutch river dikes. Acta Botanica Neerlandica 37:279-290.
    • (1988) Acta Botanica Neerlandica , vol.37 , pp. 279-290
    • Sykora, K.V.1    Schepers, E.2    Van Der Zee, F.3
  • 46
    • 0002606629 scopus 로고
    • Transformation of cover-abundance values in phytosociology and its effects on community similarity
    • Van der Maarel, E. 1979. Transformation of cover-abundance values in phytosociology and its effects on community similarity. Vegetatio 39:97-114.
    • (1979) Vegetatio , vol.39 , pp. 97-114
    • Van Der Maarel, E.1
  • 47
    • 0026565172 scopus 로고
    • Phenology and seed production in Chenopodium rubrum, Rumex maritimus, and Rumex palustris as related to photoperiod in river forelands
    • Van der Sman, A. J. M., C. W. P. M. Blom, and H. M. Van de Steeg. 1992. Phenology and seed production in Chenopodium rubrum, Rumex maritimus, and Rumex palustris as related to photoperiod in river forelands. Canadian Journal of Botany 70:392-400.
    • (1992) Canadian Journal of Botany , vol.70 , pp. 392-400
    • Van Der Sman, A.J.M.1    Blom, C.W.P.M.2    Van De Steeg, H.M.3
  • 48
    • 0026096695 scopus 로고
    • The role of ethylene in shoot elongation with respect to survival and seed output of flooded Rumex maritimus L. plants
    • Van der Sman, A. J. M., L. A. C. J. Voesenek, C. W. P. M. Blom, F. Harren, and J. Reuss. 1991. The role of ethylene in shoot elongation with respect to survival and seed output of flooded Rumex maritimus L. plants. Functional Ecology 5:304-313.
    • (1991) Functional Ecology , vol.5 , pp. 304-313
    • Van Der Sman, A.J.M.1    Voesenek, L.A.C.J.2    Blom, C.W.P.M.3    Harren, F.4    Reuss, J.5
  • 49
  • 51
    • 0037327037 scopus 로고    scopus 로고
    • Extreme flooding events on the Rhine and the survival and distribution of riparian plant species
    • Vervuren, P. J. A., C. W. P. M. Blom, and H. de Kroon. 2003. Extreme flooding events on the Rhine and the survival and distribution of riparian plant species. Journal of Ecology 91:135-146.
    • (2003) Journal of Ecology , vol.91 , pp. 135-146
    • Vervuren, P.J.A.1    Blom, C.W.P.M.2    De Kroon, H.3
  • 52
    • 0029661691 scopus 로고    scopus 로고
    • Flooding-induced adventitious rooting in Rumex: Morphology and development in an ecological perspective
    • Visser, E. J., C. W. P. M. Blom, and L. A. C. J. Voesenek. 1996. Flooding-induced adventitious rooting in Rumex: morphology and development in an ecological perspective. Acta Botanica Neerlandica 45:17-28.
    • (1996) Acta Botanica Neerlandica , vol.45 , pp. 17-28
    • Visser, E.J.1    Blom, C.W.P.M.2    Voesenek, L.A.C.J.3
  • 53
    • 0030961431 scopus 로고    scopus 로고
    • Elongation by primary lateral roots and adventitious roots during conditions of hypoxia and high ethylene concentration
    • Visser, E. J. W., R. H. M. Nabben, C. W. P. M. Blom, and L. A. C. J. Voesenek. 1997. Elongation by primary lateral roots and adventitious roots during conditions of hypoxia and high ethylene concentration. Plant, Cell and Environment 20:647-653.
    • (1997) Plant, Cell and Environment , vol.20 , pp. 647-653
    • Visser, E.J.W.1    Nabben, R.H.M.2    Blom, C.W.P.M.3    Voesenek, L.A.C.J.4
  • 56
    • 0027145446 scopus 로고
    • Submergence-induced ethylene synthesis entrapment, and growth in two plant species with contrasting flooding resistances
    • Voesenek, L. A. C. J., M. Banga, R. H. Thier, C. M. Mudde, F. J. M. Harren, G. W. M. Barendse, and C. W. P. M. Blom. 1993a. Submergence-induced ethylene synthesis entrapment, and growth in two plant species with contrasting flooding resistances. Plant Physiology 103:783-791.
    • (1993) Plant Physiology , vol.103 , pp. 783-791
    • Voesenek, L.A.C.J.1    Banga, M.2    Thier, R.H.3    Mudde, C.M.4    Harren, F.J.M.5    Barendse, G.W.M.6    Blom, C.W.P.M.7
  • 57
    • 0024935921 scopus 로고
    • Growth responses of Rumex species in relation to submergence and ethylene
    • Voesenek, L. A. C. J., and C. W. P. M. Blom. 1989a. Growth responses of Rumex species in relation to submergence and ethylene. Plant, Cell and Environment 12:433-439.
    • (1989) Plant, Cell and Environment , vol.12 , pp. 433-439
    • Voesenek, L.A.C.J.1    Blom, C.W.P.M.2
  • 59
    • 0002415794 scopus 로고    scopus 로고
    • Stimulated shoot elongation: A mechanism of semiaquatic plants to avoid submergence stress
    • H. R. Lerner, editor. Marcel Dekker, New York, New York, USA
    • Voesenek, L. A. C. J., and C. W. P. M. Blom. 1999. Stimulated shoot elongation: a mechanism of semiaquatic plants to avoid submergence stress. Pages 431-448 in H. R. Lerner, editor. Plant responses to environmental stresses: from phytohormones to genome reorganization. Marcel Dekker, New York, New York, USA.
    • (1999) Plant Responses to Environmental Stresses: From Phytohormones to Genome Reorganization , pp. 431-448
    • Voesenek, L.A.C.J.1    Blom, C.W.P.M.2
  • 60
    • 0027079758 scopus 로고
    • Germination and emergence of Rumex in river flood-plains. II. The role of perianth, temperature, light and hypoxia
    • Voesenek, L. A. C. J., M. C. C. de Graaf, and C. W. P. M. Blom. 1992a. Germination and emergence of Rumex in river flood-plains. II. The role of perianth, temperature, light and hypoxia. Acta Botanica Neerlandica 41:331-343.
    • (1992) Acta Botanica Neerlandica , vol.41 , pp. 331-343
    • Voesenek, L.A.C.J.1    De Graaf, M.C.C.2    Blom, C.W.P.M.3
  • 62
    • 0001792199 scopus 로고
    • Petiole elongation in Rumex during submergence and ethylene exposure: The relative contributions of cell division and cell expansion
    • Voesenek, L. A. C. J., P. J. M. Perik, C. W. P. M. Blom, and M. M. A. Sassen. 1990. Petiole elongation in Rumex during submergence and ethylene exposure: the relative contributions of cell division and cell expansion. Journal of Plant Growth Regulation 9:13-17.
    • (1990) Journal of Plant Growth Regulation , vol.9 , pp. 13-17
    • Voesenek, L.A.C.J.1    Perik, P.J.M.2    Blom, C.W.P.M.3    Sassen, M.M.A.4
  • 63
    • 0027444414 scopus 로고
    • The role of flooding resistance in the establishment of Rumex seedlings in river flood plains
    • Voesenek, L. A. C. J., F. J. M. M. Van Oorschot, A. J. M. Smits, and C. W. P. M. Blom. 1993b. The role of flooding resistance in the establishment of Rumex seedlings in river flood plains. Functional Ecology 7:105-114.
    • (1993) Functional Ecology , vol.7 , pp. 105-114
    • Voesenek, L.A.C.J.1    Van Oorschot, F.J.M.M.2    Smits, A.J.M.3    Blom, C.W.P.M.4
  • 65
    • 0031170949 scopus 로고    scopus 로고
    • A homologue of the Arabidopsis thaliana ERS gene is actively regulated in Rumex palustris upon flooding
    • Vriezen, W. H., C. P. E. Van Rijn, L. A. C. J. Voesenek, and C. Mariani. 1997. A homologue of the Arabidopsis thaliana ERS gene is actively regulated in Rumex palustris upon flooding. Plant Journal 11:1265-1271.
    • (1997) Plant Journal , vol.11 , pp. 1265-1271
    • Vriezen, W.H.1    Van Rijn, C.P.E.2    Voesenek, L.A.C.J.3    Mariani, C.4


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