跳到主要內容

簡易檢索 / 詳目顯示

研究生: 陳冀嫺
Ji-Xian Li
論文名稱: 甘藷桃園二號對鹽分逆境之抗氧化物質的生化反應研究
Biochemical studies of salt stress on antioxidants in Ipomoea batatas (L.) Lam.cv. Taoyuan 2
指導教授: 李賢淇
口試委員:
學位類別: 碩士
Master
系所名稱: 生醫理工學院 - 生命科學系
Department of Life Science
畢業學年度: 89
語文別: 中文
論文頁數: 77
相關次數: 點閱:10下載:0
分享至:
查詢本校圖書館目錄 查詢臺灣博碩士論文知識加值系統 勘誤回報

  • 當植物遭遇環境逆境時,它會促進活性氧的生成,處於逆境下的植物
    能調適或增強其抗氧化防禦系統(包括抗氧化酵素及非酵素性抗氧
    化物) 。本試驗主要是研究「桃園二號葉用甘藷」於鹽分逆境下,葉
    片的抗氧化酵素及非酵素性抗氧化物之變化,並且研究此甘藷在鹽分
    逆境下,其抗氧化解毒機制。結果顯示桃園二號葉用甘藷之抗氧化酵
    素及非酵素性抗氧化物皆會受鹽分逆境影響,在鹽分(90~150mM 氯
    化鈉) 處理後,抗氧化酵素例如superoxide dismutase, catalase,
    ascorbate peroxidase, guaiacol peroxidase 和glutathione reductase 之活
    性有增加的趨勢,非酵素性抗氧化物例如total ascorbate 和glutathione
    之含量則有減少的趨勢,葉綠素相對量則減低,離子滲漏增加。低濃
    度鹽分(30~90mM 氯化鈉) 處理時,脂質過氧化會有減少的趨勢,
    但高濃度鹽分(120~150mM 氯化鈉) 處理時,卻會有增加的趨勢。本
    試驗結果暗示甘藷在鹽分環壓之下有調適此逆境的能力,它可能牽涉
    一些關鍵的酵素性和非酵素性抗氧化系統。



    generation of reactive oxygen species. Plants under stresses could modify
    or increase antioxidative defense systems (include antioxidative enzymes
    and non-enzymatic antioxidants). Experiments were conducted mainly to
    study the changes of antioxidative enzymes and non-enzymatic
    antioxidants in sweet potato (Ipomoea batatas (L.) Lam.cv. Taoyuan 2)
    leaves under salt stress. An antioxidative detoxification mechanism in the
    sweet potato under salt stress is also investigated. Results showed that
    antioxidative enzymes and non-enzymatic antioxidants in Ipomoea
    batatas (L.) Lam.cv. Taoyuan 2 were affected by salt stress. The activities
    of antioxidative enzymes such as superoxide dismutase, catalase,
    ascorbate peroxidase, guaiacol peroxidase and glutathione reductase
    tended to increase after salt (90~150mM sodium chloride) treatments.
    The contents of non-enzymatic antioxidants such as total ascorbate and
    glutathione tended to decrease. The chlorophyll relative contents also
    decreased. Electrolyte leakage increased. Lipid peroxidation tended to
    decrease with lower concentrations of salt (30~90mM sodium chloride)
    treatments, but tended to increase with higher concentrations of salt
    (120~150mM sodium chloride) treatments. Results suggest that sweet
    potato has an ability to respond to salt stress, they may relate to involve
    of several key enzymatic and non-enzymatic antioxidant systems.

    I 中文摘要… … … … … … … … … … … … … … … … … … … … . . … . … … … . 1 英文摘要… … … … … … … … … … … … … … … … … … … . . … … … … … ..2 壹、前言… … … … … … … … … … … … … … … … … … … … … . . … … … ..3 貳、材料與方法… … … … … … … … … … … … … … … … … … … … . . … .21 參、結果… … … … … … … … … … … … … … … … … … . . … … … … … … .34 肆、討論… … … … … … … … … … … … … … … … … … … … … … … . . … ..40 伍、展望… … … … … … … … … … … … … … … … … … … … … … … … ...44 陸、參考文獻… … … … … … … … … … … … … … … … … … … … … … … 47 柒、圖… … … … … … … … … … … … … … … … … … … … … … … … … ...64

    47
    高景輝、林安秋. (1985). 鹽性與植物生長. 科學農業. 33: 365-368.
    王嘉宏、劉麗飛、詹明才. (2000). 基因改造作物(GM 作物) 的衝擊
    與未來. 科學農業. 48: 229-235.
    辛仲文、姜金龍. (1999). 葉菜甘藷新品種—桃園2 號. 臺灣農業. 35:
    黃士懿. (1996). 天然抗氧化劑面面觀. 中化藥訊. 30: 27-32.
    馮文虎. (1994). 淺談自由基與抗氧化物. 中華民國醫檢會報. 9: 34-
    歐湧淳. (1994). 自由基、活性氧與疾病. 中華民國醫檢會報. 9: 44-49.
    Allen, R. D. (1995) Dissection of oxidative stress tolerance using
    transgenic plants. Plant Physiol. 107: 1049-1054.
    Allen, R. D., Webb, R. P. and Schake, S. A. (1997) Use of transgenic
    plants to study antioxidant defenses. Free Radic. Biol. Med. 23: 473-
    Alscher, R. G., Donahue, J. L. and Cramer, C. L. (1997) Reactive
    48
    oxygen species and antioxidants: relationships in green cells. Physiol.
    Plant. 100: 224-233.
    Anderson, J. V., Chevone, B. I. and Hess, J. L. (1992) Seasonal
    variation in the antioxidant system of eastern white pine needles.
    Plant Physiol. 98: 501-508.
    Asada, K. (1992) Ascorbate peroxidase – a hydrogen peroxide –
    scavenging enzyme in plants. Physiol. Plant. 85: 235-241.
    Asada, K. (1984) Chloroplast: formation of active oxygen and its
    scavenging. Methods Enzymol. 105: 422-429.
    Beckmam, K. B. and Ames, B. N. (1998) The free radical theory of
    aging matures. Physiol. Rev. 78: 547-581.
    Blumwald, E., Aharon, G. S. and Apse, M. P. (2000) Sodium transport
    in plant cells. Biochimica et Biophysica Acta. 1465: 140-151.
    Bowler, C., Van Montagu, M. and Inzé, D. (1992) Superoxide
    dismutase and stress tolerance. Annu. Rev. Plant Physiol. Plant Mol.
    Biol. 43: 83-116.
    Bowler, C., Van Camp, W., Van Montagu, M. and Inzé, D. (1994)
    Superoxide dismutase in plants. Crit Rev Plant Sci. 13: 199-218.
    49
    Buchanan-Wollaston, V. (1997) The molecular biology of leaf
    senescence. J. Exp. Bot. 48: 181-199.
    Bueno, P., Piqueras, A., Kurepa, J., Savouré, A., Verbruggen, N., Van
    Montagu, M. and Inzé, D. (1998) Expression of antioxidant
    enzymes in response to abscisic acid and high osmoticum in tobacco
    BY-2 cell cultures. Plant Sci. 138: 27-34.
    Cakmak, I. and Marschner, H. (1992) Magnesium deficiency and high
    light intensity enhance activities of superoxide dismutase, ascorbate
    peroxidase, and glutathione reductase in bean leaves. Plant Physiol.
    98: 1222-1227.
    Cakmak, I., Strbac, D. and Marschner, H. (1993) Activities of
    hydrogen peroxide-scavenging enzymes in germinating wheat seeds.
    J. Exp. Bot. 44: 127-132.
    Chaoui, A., Mazhoudi, S., Ghorbal, M. H. and Ferjani, E. E. (1997)
    Cadmium and zinc induction of lipid peroxidation and effects on
    antioxidant enzyme activities in bean (Phaseolus vulgaris L.). Plant
    Sci. 127: 139-147.
    Chow, C. K. (1992) Nutrition and cellular antioxidant defense. J. Chin.
    Nutr. Soc. 17: 1-14.
    Comba, M. E., Benavides, M. P. and Tomaro, M. L. (1998) Effect of
    50
    salt stress on antioxidant defence system in soybean root nodules.
    Aust. J. Plant Physiol. 25: 665-671.
    Cook, N. C. and Samman, S. (1996) Flavonoids – Chemistry,
    metabolism, cardioprotective effects, and dietary sources. Nutritional
    Biochemistry 7: 66-76.
    del Río, L. A., Sandalio, L. M., Palma, J. M., Bueno, P. and Corpas, F.
    J. (1992) Metabolism of oxygen radicals in peroxisomes and cellular
    implications. Free Radic. Biol. Med. 13: 557-580.
    Dhindsa, R. S. and Matowe, W. (1981) Drought tolerance in two mosses:
    correlated with enzymatic defence against lipid peroxidation. J. Exp.
    Bot. 32: 79-91.
    Dhindsa, R. S., Plumb-Dhindsa, P. and Thorpe, T. A. (1981) Leaf
    senescence: correlated with increased levels of membrane
    permeability and lipid peroxidation, and decreased levels of
    superoxide dismutase and catalase. J. Exp. Bot. 32: 93-101.
    Dionisio-Sese, M. L. and Tobita, S. (1998) Antioxidant responses of rice
    seedlings to salinity stress. Plant Sci. 135: 1-9.
    El-Enany, A. E. (1997) Glutathione metabolism in soybean calluscultures
    as affected by salinity. Biol. Plant. 39: 35-39.
    51
    Elstner, E. F. (1982) Oxygen activation and oxygen toxicity. Annu. Rev.
    Plant Physiol. 33: 73-96.
    Fadzilla, N. M., Finch, R. P. and Burdon, H. (1997) Salinity, oxidative
    stress and antioxidant responses in shoot cultures of rice. J. Exp. Bot.
    307: 325-331.
    Foster, J. G. and Hess, J. L. (1982) Oxygen effects on maize leaf
    superoxide dismutase and glutathione reductase. Phytochemistry 21:
    1527-1532.
    Foster, J. G. and Hess, J. L. (1980) Responses of superoxide dismutase
    and glutathione reductase activities in cotton leaf tissue exposed to
    an atmosphere enriched in oxygen. Plant Physiol. 66: 482-487.
    Foyer, C. H. and Halliwell, B. (1976) The presence of glutathione and
    glutathione reductase in chloroplasts: a proposed role in ascorbic
    acid metabolism. Planta 133: 21-25.
    Foyer, C. H., Descourvieres, P. and Kunert, K. J. (1994) Protection
    against oxygen radicals: an important defence mechanism studied in
    transgenic plants. Plant Cell Environ. 17: 507-523.
    Foyer, C. H., Souriau, N., Perret, S., Lelandais, M., Kunert, K. J.,
    Pruvost, C. and Jouanin, L. (1995) Overexpression of glutathione
    reductase but not glutathione synthetase leads to increases in
    52
    antioxidant capacity and resistance to photoinhibition in poplar trees.
    Plant Physiol. 109: 1047-1057.
    Fridovich, I. (1986) Biological effects of the superoxide radical. Arch.
    Biochem. Biophys. 247: 1-11.
    Fridovich, I. (1995) Superoxide radical and superoxide dismutases. Annu.
    Rev. Biochem. 64: 97-112.
    Fryer, M. J. (1992) The antioxidant effects of thylakoid vitamin E (a-
    tocopherol). Plant. Cell. Environ. 15: 381-392.
    Gallego, S. M., Benavídes, M. P. and Tomaro, M. L. (1996) Effect of
    heavy metal ion excess on sunflower leaves: evidence for
    involvement of oxidative stress. Plant Sci. 121: 151-159.
    Gamble, P. E. and Burke, J. J. (1984) Effect of water stress on the
    chloroplast antioxidant system: alterations in glutathione reductase
    activity. Plant Physiol. 76: 615-621.
    Gossett, D. R., Millhollon, E. P. and Lucas, M. C. (1994) Antioxidant
    response to salt stress in salt-tolerant and salt-sensitive cultivars of
    cotton. Crop Sci. 34: 706-714.
    Gueta-Dahan, Y., Yaniv, Z., Zilinskas, B. A. and Ben-Hayyim, G.
    (1997) Salt and oxidative stress: similar and specific responses and
    53
    their relation to salt tolerance in Citrus. Planta 203: 460-469.
    Hernández, J. A., Corpas, F. J., Gómez, M., del Río, L. A. and Sevilla,
    F. (1993) Salt-induced oxidative stress mediated by activated oxygen
    species in pea leaf mitochondria. Physiol. Plant. 89: 103-110.
    Hernández, J. A., Olmos, E., Corpas, F. J., Sevilla, F. and del Río, L.
    A. (1995) Salt-induced oxidative stress in chloroplasts of pea plants.
    Plant Sci. 105: 151-167.
    Hoagland, P. R. and Arnon, D. I. (1950) The water culture method for
    growing plants without soil. Calif. Agric. Exp. Stn. Circ. 347.
    Hodges, D. M., Andrews, C. J., Johnson, D. A. and Hamilton, R. I.
    (1996) Antioxidant compound responses to chilling stress in
    differentially sensitive inbred maize lines. Physiol. Plant. 98: 685-
    692.
    Hossain, M. A., Nakano, Y. and Asada, K. (1984)
    Monodehydroascorbate reductase in spinach chloroplasts and its
    participation in regeneration of ascorbate for scavenging hydrogen
    peroxide. Plant Cell Physiol. 25: 385-395.
    Huang, C. Y. (1996) Salt-stress induces lipid degradation and lipid phase
    transition in plasma membrane of soybean plants. Taiwania 41: 96-
    104.
    54
    Huang, C. Y. and Chen, Y. M. (1995) Role of glutathione reductase and
    related enzymes in salt-tolerant mechanism of soybean plants grown
    under salt-stress condition. Taiwania 40: 21-34.
    Ishikawa, T., Yoshimura, K., Sakai, K., Tamoi, M., Takeda, T. and
    Shigeoka, S. (1998) Molecular characterization and physiological
    role of a glyoxysome-bound ascorbate peroxidase from spinach.
    Plant Cell Physiol. 39: 23-34.
    Iturbe-Ormaetxe, I., Escuredo, P. R., Arrese-Igor, C. and Becana, M.
    (1998) Oxidative damage in pea plants exposed to water deficit or
    paraquat. Plant Physiol. 116: 173-181.
    Jablonski, P. P. and Anderson, J. W. (1981) Light dependent reduction
    of dehydroascorbate by ruptured pea chloroplasts. Plant Physiol. 67:
    1239-1244.
    Jahnke, L. S., Hull, M. R. and Long, S. P. (1991) Chilling stress and
    oxygen metabolizing enzymes in Zea mays and Zea diploperennis.
    Plant Cell Environ. 14: 97-104.
    Jiménez, A., Hernández, J. A., Barcelo, A. R., Sandalio, L. M., del
    Río, L. A. and Sevilla, F. (1998a) Mitochondrial and peroxisomal
    ascorbate peroxidase of pea leaves. Physiol. Plant. 104: 687-692.
    55
    Jiménez, A., Hernández, J. A., Pastori, G., del Río, L. A. and Sevilla,
    F. (1998b) Role of the ascorbate-glutathione cycle of mitochondria
    and peroxisomes in the senescence of pea leaves. Plant Physiol. 118:
    1327-1335.
    Kalir, A., Omri, G. and Poljakoff-Mayber, A. (1984) Peroxidase and
    catalase activity in leaves of Halimione portulacoides exposed to
    salinity. Physiol. Plant. 62: 238-244.
    Kanofsky, J. R. and Sima, P. D. (1995) Singlet oxygen generation from
    the reaction of ozone with plant leaves. J. Biol. Chem. 270: 7850-
    7852.
    Kato, M. and Shimizu, S. (1987) Chlorophyll metabolism in higher
    plants. VII. Chlorophyll degradation in senescing tobacco leaves;
    phenolic-dependent peroxidase degradation. Can. J. Bot. 65: 729-
    735.
    Lacan, D. and Baccou, J. C. (1998) High levels of antioxidant enzymes
    correlate with delayed senescence in nonnetted muskmelon fruits.
    Planta 204: 377-382.
    Law, M. Y., Charles, S. A. and Halliwell, B. (1983) Glutathione and
    ascorbic acid in spinach(Spinacia oleracea) chloroplasts – the effect
    of hydrogen peroxide and of paraquat. Biochem. J. 210: 899-903.
    56
    Leshem, Y. Y. (1988) Plant senescence processes and free radicals. Free
    Radic. Biol. Med. 5: 39-49.
    Lidon, F. C. and Teixeira, M. G. (2000) Oxy radicals production and
    control in the chloroplast of Mn-treated rice. Plant Sci. 152: 7-15.
    Loggini, B., Scartazza, A., Brugnoli, E. and Navari-Izzo, F. (1999)
    Antioxidative defense system, pigment composition, and
    photosynthetic efficiency in two wheat cultivars subjected to drought.
    Plant Physiol. 119: 1091-1099.
    Mano, J., Ushimaru, T. and Asada, K. (1997) Ascorbate in thylakoid
    lumen as an endogenous electron donor to photosystem II: protection
    of thylakoids from photoinhibition and regeneration of ascorbate in
    stroma by dehydroascorbate reductase. Photosynth. Res. 53: 197-
    204.
    May, M. J. and Leaver, C. J. (1993) Oxidative stimulation of
    glutathione synthesis in Arabidopsis thaliana suspension cultures.
    Plant Physiol. 103: 621-627.
    McKersie, B. D., Bowley, S. R., Harjanto, E. and Leprince, O. (1996)
    Water-deficit tolerance and field performance of transgenic alfalfa
    overexpressing superoxide dismutase. Plant Physiol. 111: 1177-
    1181.
    57
    McKersie, B. D., Chen, Y., de Beus, M., Bowley, S. R., Bowler, C.,
    Inzé, D., D’Halluin, K., Botterman, J. (1993) Superoxide
    dismutase enhances tolerance of freezing stress in transgenic alfalfa
    (Medicago sativa L.). Plant Physiol. 103: 1155-1163.
    Meneguzzo, S., Sgherri, C. L. M., Navari-Izzo, F. and Izzo, R. (1998)
    Stromal and thylakoid-bound ascorbate peroxidases in NaCl-treated
    wheat. Physiol. Plant. 104: 735-740.
    Miyake, C. and Asada, K. (1992) Thylakoid-bound ascorbate
    peroxidase in spinach chloroplasts and photoreduction of its primary
    oxidation product monodehydroascorbate radicals in thylakoids.
    Plant Cell Physiol. 33: 541-553.
    Monk, L. S., Fagerstedt, K. V. and Crawford, R. M. M. (1989)
    Oxygen toxicity and superoxide dismutase as an antioxidant in
    physiological stress. Physiol. Plant. 76: 456-459.
    Neumann, P. (1997) Salinity resistance and plant growth revisited. Plant
    Cell Environ. 20: 1193-1198.
    Osmond, C. B. and Grace, S. C. (1995) Perspectives on photoinhibition
    and photorespiration in the field: quintessential inefficiencies of the
    light and dark reactions of photosynthesis. J. Exp. Bot. 46: 1351-
    1362.
    58
    Paoletti, F., Aldinucci, D., Mocali, A. and Caparrini, A. (1986) A
    sensitive spectrophotometric method for the determination of
    superoxide dismutase activity in tissue extracts. Anal. Biochem. 154:
    536-541.
    Pastori, G. M. and Trippi, V. S. (1993) Antioxidative protection in a
    drought-resistant maize strain during leaf senescence. Physiol. Plant.
    87: 227-231.
    Pastori, G. M. and Trippi, V. S. (1992) Oxidative stress induces high
    rate of glutathione reductase synthesis in a drought-resistant maize
    strain. Plant Cell Physiol. 33: 957-961.
    Ranieri, A., Castagna, A., Lorenzini, G. and Soldatini, G. F. (1997)
    Changes in thylakoid protein patterns and antioxidant levels in two
    wheat cultivars with different sensitivity to sulfur dioxide. Environ.
    Exp. Bot. 37: 125-135.
    Rao, M. V. and Dubey, P. S. (1993) Response of hydrogen peroxide
    scavenging system in two soybean cultivars exposed to SO2:
    experimental evidence for the detoxification of SO2 by enhanced
    H2O2 scavenging components. Environ. Pollut. 82: 99-105.
    Rodríguez-Rosales, M. P., Kerkeb, L., Bueno, P. and Donaire, J. P.
    (1999) Changes induced by NaCl in lipid content and composition,
    lipoxygenase, plasma membrane H+-ATPase and antioxidant enzyme
    59
    activities of tomato (Lycopersicon esculentum. Mill) calli. Plant Sci.
    143: 143-150.
    Rubinstein, B. and Luster, D. G. (1993) Plasma membrane redox
    activity: Components and role in plant processes. Annu. Rev. Plant
    Physiol. Plant Mol. Biol. 44: 131-155.
    Salin, M. L. (1987) Toxic oxygen species and protective systems of the
    chloroplast. Physiol. Plant. 72: 681-689.
    Scandalios, J. G. (1993) Oxygen stress and superoxide dismutases. Plant
    Physiol. 101: 7-12.
    Schmidt, A. and Kunert, K. J. (1986) Lipid peroxidation in higher
    plants: the role of glutathione reductase. Plant Physiol. 82: 700-702.
    Seeman, J. R. and Critchley, C. (1985) Effects of salt stress on the
    growth, ion content, stomatal behaviour and photosynthetic capacity
    of a salt-sensitive species, Phaseolus vulgaris L. Planta 164: 151-
    162.
    Senaratna, T., McKersie, B. D. and Stinson, R. H. (1985) Stimulation
    of dehydration injury to membranes from soybean axes by free
    radicals. Plant Physiol. 77: 472-474.
    Sgherri, C. L. M. and Navari-Izzo, F. (1995) Sunflower seedlings
    60
    subjected to increasing water deficit stress: oxidative stress and
    defence mechanisms. Physiol. Plant. 93: 25-30.
    Sgherri, C. L. M., Pinzino, C. and Navari-Izzo, F. (1996) Sunflower
    seedlings subjected to increasing stress by water deficit: changes in
    O2
    ·- production related to the composition of thylakoid membranes,
    Physiol. Plant . 96: 446-52.
    Siefermann-Harms, D. (1987) The light-harvesting and protective
    functions of carotenoids in photosynthetic membranes. Physiol.
    Plant. 69: 561-568.
    Smirnoff, N. (1996) The function and metabolism of ascorbic acid in
    plants. Ann. Bot. 78: 661-669.
    Smirnoff, N. (1993) The role of active oxygen in the response of plants
    to water deficit and dessication. New Phytol. 125: 27-58.
    Smirnoff, N. and Colombé, S. V. (1988) Drought influences the activity
    of enzymes of the chloroplast hydrogen peroxide scavenging system.
    J. Exp. Bot. 39: 1097-1108.
    Takahama, U. and Nishimura, M. (1975) Formation of singlet
    molecular oxygen in illuminated chloroplasts. Effects on
    photoinactivation and lipid peroxidation. Plant Cell Physiol. 16:
    737-748.
    61
    Takeda, T., Yokota, A. and Shigeoka, S. (1995) Resistance of
    photosynthesis to hydrogen peroxide in algae. Plant Cell Physiol. 36:
    1089-1095.
    Tanaka, Y., Hibino, T., Hayashi, Y., Tanaka, A., Kishitani, S., Takabe,
    T., Yokota, S. and Takabe, T. (1999) Salt tolerance of transgenic
    rice overexpressing yeast mitochondrial Mn-SOD in chloroplasts.
    Plant Sci. 148: 131-138.
    Teisseire, H. and Guy, V. (2000) Copper-induced changes in antioxidant
    enzymes activities in fronds of duckweed (Lemna minor). Plant Sci.
    153: 65-72.
    Thompson, J. E., Ledge, R. L. and Barber, R. F. (1987) The role of
    free radicals in senescence and wounding. New Phytol. 105: 317-
    344.
    Trippi, V. S. and Thimann, K. V. (1983) The exudation of solutes
    during senescence of oat leaves. Physiol. Plant. 58: 21-28.
    Tsuchihashi, H., Kigoshi, M., Iwatsuki, M. and Niki, E. (1995) Action
    of b-carotene as an antioxidant against lipid peroxidation. Arch.
    Biochem. Biophys. 323: 137-147.
    Van Camp, W., Capiau, K., Van Montagu, M., Inzé, D. and Slooten, L.
    62
    (1996) Enhancement of oxidative stress tolerance in transgenic
    tobacco plants overproducing Fe-superoxide dismutase in
    chloroplasts. Plant Physiol. 112: 1703-1714.
    Van Camp, W., Inzé, D. and Van Montagu, M. (1997) The regulation
    and function of tobacco superoxide dismutases. Free Radic. Biol.
    Med. 23: 515-520.
    Walker, M. A. and McKersie, B. D. (1993) Role of the ascorbateglutathione
    antioxidant system in chilling resistance of tomato. J.
    Plant Physiol. 141: 234-239.
    Wise, R. R. and Naylor, A. W. (1987) Chilling-enhanced photooxidation.
    Evidence for the role of singlet oxygen and superoxide in the
    breakdown of pigments and endogenous antioxidants. Plant Physiol.
    83: 278-282.
    Yruela, I., Pueyo, J. J., Alonso, P. J. and Picorel, R. (1996)
    Photoinhibition of photosystem II from higher plants: effect of
    copper inhibition. J. Biol. Chem. 271: 27408-27415.
    Yu, Q. and Rengel, Z. (1999) Drought and salinity differentially
    influence activities of superoxide dismutases in narrow-leafed lupins.
    Plant Sci. 142: 1-11.
    Zhang, J. and Kirkham, M. B. (1994) Drought-stress-induced changes
    in activities of superoxide dismutase, catalase, and peroxidase in
    wheat species. Plant Cell Physiol. 35: 785-791.
    Zhang, J. and Kirkham, M. B. (1996) Enzymatic responses of the
    ascorbate-glutathione cycle to drought in sorghum and sunflower
    plants. Plant Sci. 113: 139-147.

    QR CODE
    :::