鎘對阿拉伯芥在於其根部生長長度的影響方面最為顯著。在鎘存在於培養基的期間，過氧化氫及過氧化酶都隨著鎘濃度的提高而升高。阿拉伯芥根部木質素的含量在鎘處理下亦略有升高（48小時）。阿拉伯芥可以耐受在含高濃度的鎘(500 µM)存在的環境，原因在於此濃度下生長的阿拉伯芥根部組織依然存在有高量的過氧化氫而未被過氧化酶降解用於合成木質素。

The adverse effect of Cd on growth is apparent from the reduction in root length of the Cd-treated Arabidopsis thaliana roots. The increase of the levels of H2O2 was observed in Cd-treated A. thaliana roots. The lignin biosynthesis related enzymes, POXs and laccases were enhanced during the Cd treatments. The lignin contents slightly increased in Cd-treated A. thaliana roots（48 h）. The A. thaliana can be tolerant to high concentration of Cd (500 µM), and only part of high levels of H2O2 accumulated in Cd-treated tissues are used by POXs to synthesize the lignin.

TABLE OF CONTENTS Chinese abstract -------------------------------------I
English abstract -------------------------------------II
Table of contents -----------------------------------III
List of figures ---------------------------------------IV
Introduction -----------------------------------------1
Materials and methods --------------------------13
Results -----------------------------------------------20
Discussion -------------------------------------------23
Reference --------------------------------------------27
Figures -----------------------------------------------38

Reference Alvarez ME, Lamb C (1997) Oxidative burst mediated defense responses in plant disease resistance. In JG Scandalios, ed, Oxidative Stress and the Molecular Biology of Antioxidant Defenses. Cold Spring Harbor Laboratory Press, New York, 815-839 Alfred M. Mayer and Richard C. Staples (2002) Laccase: new functions for an old enzyme. Phytochemistry 60(6), 551-649. Asada.K (1999) The water–eater cycle in chloroplasts: scavenging of active oxygens and dissipation of excess photons, Ann. Rev. Plant Physiol. Plant. Mol. Biol. 50, 601–639. Baccouch S, Chaoui A, Ferjani EE (1998) Nickel-induced oxidative damage and antioxidant responses in Zea mays shoots. Plant Physiology and Biochemistry 36, 689-694. Balestrasse KB, Benavides MP, Gallego SM; Tomaro ML (2003) Effect on cadmium stress on nitrogen metabolism in nodules and roots of soybean plants. Func. Plant Biol. 30:57-64. Bao W, O'Malley DM, Whetten R, Sederoff RR (1993) A laccase associated with lignification in loblolly pine xylem. Science 260, 636-638. Bazzaz FA, Rolfe GL, Carlson RW (1992) Effect of cadmium on photosynthesis and transpiration of excised leaves of corn and
27
sunflower. Physiologia Plantarum 32, 373–377. Barcelo.J and Poschenrieder C (1990) Plant water relations as affected by heavy metal stress: a review, J. Plant Nutr. 13, pp. 1–37. Bertrand (1985) Sur la laccase et sur le pouvoir oxydant de cette diastase. CR Acad. Sci. (Paris) 120, 266–269. Bruce R, West CA (1989) Elicitation of lignin biosynthesis and isoperoxidase activity by pectic fragments in suspension cultures of castor bean. Plant Physiology 91, 889-897. Bowler.C, T. Van Montagu and D. Inze (1992) Superoxide dismutase and stress tolerance, Ann. Rev. Plant Physiol. Plant Mol. Biol. 43, 83–116. Carpin S, Crèvecoeur M, Greppin H, Penel C (1999) Molecular cloning and tissue-specific expression of an anionic peroxidase in zucchini. Plant Physiology 120, 799-819. Chen EL, Chen YA, Chen LM, Liu ZH (2002) Effect of copper on peroxidase activity and lignin content in Raphanus sativus. Plant Physiology and Biochemistry 40, 439–444. Cho U, Seo N (2004) Oxidative stress in Arabidopsis thaliana exposed to cadmium is due to hydrogen peroxide accumulation, Plant Sci. 168:113-120.
28
Clemens S (2001) Molecular mechanisms of plant metal tolerance and homeostasis. Planta 212:475-486. Clemens S, Kim EJ, Neumann D, Schroeder JI (1999) Tolerance to toxic metals by a gene family of phytochelatin synthases from plants and yeast. EMBO J. 18:3325-3333. Clemens S, Palmgreen MG, Kramer U (2002) A long way ahead: understanding and engineering plant metal accumulation. Trends Plant Sci. 7:309-315. Cobbett CS (2000) Phytochelatins and their roles in heavy metal detoxification. Plant Physiol. 123:825-832. Cobbett C and Goldsbrough P (2002) Phytochelatins and Metallothioneins: Roles in Heavy Metal Detoxification and Homeostasis. Ann. Rev. Plant Physiol. Plant Mol. Biol. 53:159-82. Costa G, Morel JL (1994) Water relations, gas exchange and amino acid content in Cd-treated lettuce. Plant Physiol. Biochem. 32:561-570. Dalurzo HC, Sandalio LM, Gomez M, Del Río LA (1997) Cadmium infiltration of detached pea leaves: effect on its activated oxygen metabolism. Phyton-Ann. Rei. Bot. 37:59-64. Das P, Samantaray S, Rout GR (1997) Studies on cadmium toxicity in plants: a review. Environ. Pollution 98:29-36.
29
Dat JF, Van Breusegem F, Vandenabeele S, Vranová E, Van Montagu M, Inzé D (2000) Dual action of active oxygen species during plant stress responses. Cell. Mol. Life Sci. 57:779-795. De Filippis LF, Ziegler H (1993) Effect of sublethal concentrations of zinc, cadmium and mercury on the photosynthetic carbon reduction cycle of Euglena. J. Plant Physiol.142:167-172. Dietz KJ, Baier M, Kramer U (1999) Free radicals and reactive oxygen species as mediators of heavy metal toxicity in plants. In: Prasad MNV, Hagemeyer J (eds), Heavy metal stress in plants: from molecules to ecosystems, pp.73-97. Dixit V, Pandey V, Shyam R (2001) Differential antioxidative responses to cadmium in roots and leaves of pea (Pisum sativum L. cv. Azad) Journal of Experimental Botany 52, 1101-1109. Dunand, C., Tognolli, M., Overney, S., von Tobel, L., de Meyer, M., Simon, P. and Penel, C. (2002) Identification and characterisation of Ca2+-pectate binding peroxidases in Arabidopsis thaliana. J. Plant Physiol. 159, 1165–1171. Fodor A, Szabó-Nagy A, Erdei L (1995) The effects of cadmium on the fluidity and H+-ATPase activity of plasma membrane from sunflower and wheat roots. J. Plant Physiol. 14:787–792.
30
Fornazier RF, Ferreira RR, Vitória AP, Molina SMG, Lea PJ, Azevedo RA (2002) Effects of cadmium on antioxidant enzyme activities in sugar cane. Biol. Plant. 45:91-97. Foyer CH, Lopez-Delgado H, Dat JF, Scott IM (1997) Hydrogen peroxide- and glutathione-associated mechanisms of acclimatory stress tolerance and signalling. Physiologia Plantarum 100, 241–254. Foyer CH, Noctor G (2000) Tansley review no. 112, oxygen processing in photosynthesis: regulation and signaling. New Phytol 146: 359-388. Fry SC (1986) Cross-linking of matrix polymers in the growing cell wall of angiosperms. Annual Review of Plant Physiology 37, 165-186. Gallego SM, Benavides MP, Tomaro ML (1996) Effect of heavy metal ion excess on sunflower leaves: evidence for involvement of oxidative stress. Plant Science 121, 151-159. Gavnholta B, Larsenb K (2002) Molecular biology of plant laccases in relation to lignin formation. Physiologia Plantarum 116, 273–280. Grill E, Winnacker E-L, Zenk MH (1985) Phytochelatins: the principal heavy-metal complexing peptides of higher plants. Science 230: 674-676. Grill E, Gekeler W, Winnacker EL, Zenk MH (1986a) Homophytochelatins are heavy metal-binding peptides of homoglutathione containing Fabales. FEBS Letters 205:47-50.
31
Grill E, Winnacker EL, Zenk MH (1986b) Synthesis of seven different homologous phytochelatins in metal-exposed Schizosaccharomyces pombe cells. FEBS Letters 197:115-120. Groppa MD, Tomaro ML, Benavides MP (2001) Polyamines as protectors against cadmium or copper-induced oxidative damage in sunflower leaf discs. Plant Sci. 161:481-488. Halliwell B, Gutteridge JMC (1999) Free Radicals in Biology and Medicine. 3rd ed. Oxford University Press, New York. Hatfield R, Vermerris W (2001) Lignin formation in plants: The dilemma of linkage specificity. Plant Physiology 126, 1351–1357. Harvey and Walker (1999) B.M. Harvey and J.R.K. Walker , Studies with plant laccases: I. Comparison of plant and fungal laccases. Biochem. Mol. Biol. Biophys. 3 (1999), 45–51. Ha SB, Smith AP, Howden R, Dietrich WM, Bugg S (1999) Phytochelatin synthase genes from Arabidopsis and the yeast, Schizosaccharomyces pombe. Plant Cell 11:1153–64. Hall JL (2002) Cellular mechanisms for heavy metal detoxification and tolerance. J. Exp. Bot. 53:1-11. Hiraga, S., Sasaki, K., Ito, H., Ohashi, Y., Matsui, H. (2001) A large family of class III plant peroxidases. Plant Cell. Physiol. 42, 462–468.
32
Jeroen Raes, Antje Rohde, Jørgen Holst Christensen, Yves Van de Peer, and Wout Boerjan (2003) Genome-Wide Characterization of the Lignification Toolbox in Arabidopsis. Plant Physiol. 133, 1051-1071. Kahle H (1993) Response of roots of trees to heavy metals. Environmental and Experimental Botany 33, 99-119. Karpinski S, Reynolds H, Karpinska B, Wingsle G, Creissen G, Mullineaux P (1999) Systemic signaling and acclimation in response to excess excitation energy in Arabidopsis. Science 284, 654-657. Leita L, De Nobili M, Cesco S, Mondini C (1996) Analysis of intercellular cadmium forms in roots and leaves of bush bean. J. Plant Nutr. 19:527–533. Lewis NG, Davin LB, Sarkanen S (1999) The nature and function of lignins. In: Barton DHR, Nakasaki K, Methcohn O (eds) Comprehensive Natural Products Chemistry, Vol. 3, Elsevier Science, New York, 617–745. Lewis NG, Yamamoto E (1990) Lignin: occurrence, biogenesis and biodegradation. Annual Review of Plant Physiology and Molecular Biology 41, 455–496. Liszkay, A., Kenk, B., Schopfer, P. (2003). Evidence for the involvement of cell wall peroxidase in the generation of hydroxyl
33
radicals mediating extension growth. Planta 217, 658–667. Li TC, Feng TY, Chen WS, Liu ZH (2001) The acute effect of copper on the levels of indole-3-acetic acid and lignin in peanut roots. Australian Journal of Plant Physiology 28, 1-6. Mäder M (1992) Compartmentation of peroxidase isoenzymes in plant cells. In C Penel, T Gaspar, H Greppin, eds, Plant Peroxidases 1980-1990. University of Geneva, Switzerland, 37-46 Maria Dr kiewicz, Ewa Skórzy ska-Polit and Zbigniew Krupa (2004) Copper-induced oxidative stress and antioxidant defence in Arabidopsis thaliana. Biometals 17, 379-387. Mittler R (2002) Oxidative stress, antioxidants and stress tolerance. Trends Plant Sci. 7: 405-410. Müsel G, Schindler T, Bergfeld R, Ruel K, Jacquet G, Lapierre G, Speth V, Schoptfer P (1997) Structure and distribution of lignin in primary and secondary cell walls of maize coleoptiles analyzed by chemical and immunological probes. Planta 201, 146-159. Niess DH (1999) Microbial heavy-metal resistance. Applied Microbiol. Biotech. 51:730-750. Nishizono H, Kubota K, Suzuki S, Ishii F (1989) Accumulation of heavy metals in cell walls of Polygonum cuspidatum roots from metalliferous habitats. Plant Cell Physiol. 30:595–598.
34
Noctor G, Foyer CH (1998) Ascorbate and glutathione: keeping active oxygen under control. Ann. Rev. Plant Physiol. Plant Mol. Biol. 49:249–279. Sandalio LM, Dalurzo HC, Gómez M, Romero-Puertas MC, del Río LA (2001) Cadmium-induced changes in the growth and oxidative metabolism of pea plants. Journal of Experimental Botany 52, 2115–2126. Sanita di Toppi L, Gabbrielli R (1999) Response to cadmium in higher plants. Environmental and Experimental Botany 41, 105-130. Schützendübel A, Schwanz P, Teichmann T, Gross K, Langenfeld-Heyser R, Godbold DL, Polle A (2001) Cadmium-induced changes in antioxidative systems, hydrogen peroxide content, and differentiation in Scots pine roots. Plant Physiology 127, 887-898. Shim IS, Momose Y, Yamamoto A, Kim DW, Usui K (2003) Inhibition of catalase activity by oxidative stress and its relationship to salicylic acid accumulation in plants. Plant Growth Regul. 39:285–292. Somashekaraiah BV, Padmaja K, Prasad ARK (1992) Phytotoxicity of cadmium ions on germinating seedlings of mung bean (Phaseolus vulgaris): involvement of lipid peroxides in chlorophyll degradation. Physiol. Plant. 85:85–89. 35
Sterjiades R, Dean JFD, Eriksson K-EL (1992) Laccase from sycamore maple (Acer pseudoplatanus) polymerizes monolignols. Plant Physiology 99, 1162-1168. Stobart AK, Griffits W, Bukhari IA, Sherwood RP (1985) The effect of Cd2+ on the biosynthesis of chlorophyll in leaves of barley. Physiol. Plant. 63:293–298. Tognolli, M., Penel, C. et al. (2002) Analysis and expression of the class III peroxidase large gene family in Arabidopsis thaliana. Gene 288, 129–138. Tyler G, Pahlsson AM, Bengtsson G, Baath E, Tranvik L (1989) Heavy metal ecology and terrestrial plants, microorganisms and invertebrates: a review. Water, Air Soil Pollut. 47:189-2150. Pinto AP, Mota AM, de Varennes A, Pinto FC (2004) Influence of organic matter on the uptake of cadmium, zinc, copper and iron by sorghum plants. Sci. Tot. Environ 326:239–247. Poschenrieder C, Gunsé B, Barceló J (1989) Influence of cadmium on water relations, stomatal resistance, and abscisic acid content in expanding bean leaves. Plant Physiol. 90:1365-1371. Robinson NJ, Tommey AM, Kuske C, Jackson PJ (1993) Plant metallothioneins. Biochem. J. 295:1-10.
36
Romero-Puertas MC, Rodríguez-Serrano M, Corpas FJ, Gomez M, del Rio LA, Sandalio LM. (2004) Cadmium-induced subcellular accumulation of O2.- and H2O2 in pea leaves. Plant Cell Environ. 27:1122-1134. Verkleij JAC, Schat H (1990) Mechanisms of metal tolerance in higher plants. In: Shaw J. (eds), Heavy metal tolerance in plants: evolutionary aspects, pp.179–193. CRC Press, Boca Raton. Welinder KG, Justesen AF, Kjaersgard IV, Jensen RB, Rasmussen SK, Jespersen HM, Duroux L. (2002) Structural diversity and transcription of class III peroxidases from Arabidopsis thaliana. Eur J Biochem. 269 (24), 6063-6081. Wagner GJ (1993) Accumulation of cadmium in crop plants and its consequences to human health. Adv. Agron. 51:173–212.