Differential antioxidative responses to cadmium in roots and leaves of pea (Pisum sativum L. cv. Azad).

Pea (Pisum sativum L. cv. Azad) plants exposed to 4 and 40 microM of Cd for 7 d in hydroponic culture were analysed with reference to the distribution of metal, the accumulation of biomass and the metal's effects on antioxidants and antioxidative enzymes in roots and leaves. Cd-induced a decrease in plant biomass. The maximum accumulation of Cd occurred in roots followed by stems and leaves. An enhanced level of lipid peroxidation and an increased tissue concentration of hydrogen peroxide (H2O2) in both roots and leaves indicated that Cd caused oxidative stress in pea plants. Roots and leaves of pea plants responded differently to Cd with reference to the induction of enhanced activities of most of the enzymes monitored in the present study. These differential responses to Cd were further found to be associated with levels of Cd to which the plants were exposed. Cd-induced enhancement in superoxide dismutase (SOD) activity was more at 40 microM than at 4 microM in leaves. While catalase (CAT) prominently increased in leaves both at 4 and 40 microM Cd, ascorbate peroxidase (APX) showed maximum stimulation at 40 microM Cd in roots. Enhancement in glutathione reductase (GR) activity was also more at 40 microM than at 4 microM Cd in roots. While glutathione peroxidase (GPOX) activity decreased in roots and remained almost unmodified in leaves, glutathione S-transferase (GST) showed pronounced stimulation in both roots and leaves of pea plants exposed to 40 microM Cd. Increased activities of antioxidative enzymes in Cd-treated plants suggest that they have some additive function in the mechanism of metal tolerance in pea plants.

[1]  I. Fridovich,et al.  Assaying for superoxide dismutase activity: some large consequences of minor changes in conditions. , 1987, Analytical biochemistry.

[2]  C. Luna,et al.  Oxidative Damage Caused by an Excess of Copper in Oat Leaves , 1994 .

[3]  H. Schickler,et al.  Response of antioxidative enzymes to nickel and cadmium stress in hyperaccumulator plants of the genus Alyssum , 1999 .

[4]  C. Foyer,et al.  Effects of Elevated Cytosolic Glutathione Reductase Activity on the Cellular Glutathione Pool and Photosynthesis in Leaves under Normal and Stress Conditions. , 1991, Plant physiology.

[5]  L. Packer,et al.  Photoperoxidation in isolated chloroplasts. I. Kinetics and stoichiometry of fatty acid peroxidation. , 1968, Archives of biochemistry and biophysics.

[6]  H. Mehlhorn.  Ethylene‐promoted ascorbate peroxidase activity protects plants against hydrogen peroxide, ozone and paraquat , 1990 .

[7]  L. A. Del Río,et al.  A more sensitive modification of the catalase assay with the Clark oxygen electrode. Application to the kinetic study of the pea leaf enzyme. , 1977, Analytical biochemistry.

[8]  L. A. Río,et al.  Evidence for the Presence of the Ascorbate-Glutathione Cycle in Mitochondria and Peroxisomes of Pea Leaves , 1997, Plant physiology.

[9]  U. Steiner,et al.  A glutathione S-transferase with glutathione-peroxidase activity from Arabidopsis thaliana. Molecular cloning and functional characterization. , 1993, European journal of biochemistry.

[10]  G. Peterson,et al.  A simplification of the protein assay method of Lowry et al. which is more generally applicable. , 1977, Analytical biochemistry.

[11]  P. A. Rea,et al.  1-Chloro-2,4-Dinitrobenzene-Elicited Increase in Vacuolar Glutathione-S-Conjugate Transport Activity , 1995, Plant physiology.

[12]  O. Griffith,et al.  Determination of glutathione and glutathione disulfide using glutathione reductase and 2-vinylpyridine. , 1980, Analytical biochemistry.

[13]  J. Dat,et al.  Hydrogen peroxide‐ and glutathione‐associated mechanisms of acclimatory stress tolerance and signalling , 1997 .

[14]  P. Urwin,et al.  Expression of the pea genePsMTA inE. coli Metal‐binding properties of the expressed protein , 1991, FEBS letters.

[15]  H. Rennenberg.  Glutathione metabolism and possible biological roles in higher plants , 1980 .

[16]  I. K. Smith,et al.  Assay of glutathione reductase in crude tissue homogenates using 5,5'-dithiobis(2-nitrobenzoic acid). , 1988, Analytical biochemistry.

[17]  M. Nishimura,et al.  A novel isoenzyme of ascorbate peroxidase localized on glyoxysomal and leaf peroxisomal membranes in pumpkin. , 1995, Plant & cell physiology.

[18]  S. Mori,et al.  Excess copper induces a cytosolic Cu,Zn -superoxide dismutase in soybean root , 1992 .

[19]  A. Chaoui,et al.  Cadmium and zinc induction of lipid peroxidation and effects on antioxidant enzyme activities in bean (Phaseolus vulgaris L.) , 1997 .

[20]  P. Mullineaux,et al.  Glutathione Reductase and Ascorbate Peroxidase , 2019, Causes of Photooxidative Stress and Amelioration of Defense Systems in Plants.

[21]  Y. Matsuda,et al.  Abrupt increase in the level of hydrogen peroxide in leaves of winter wheat is caused by cold treatment. , 1991, Plant physiology.

[22]  M. Baier,et al.  Free Radicals and Reactive Oxygen Species as Mediators of Heavy Metal Toxicity in Plants , 1999 .

[23]  L. Toppi,et al.  Response to cadmium in higher plants , 1999 .

[24]  Carole L. Cramer,et al.  Reactive oxygen species and antioxidants: Relationships in green cells , 1997 .

[25]  H. Rennenberg,et al.  Cysteine, gamma-Glutamylcysteine, and Glutathione Levels in Maize Seedlings : Distribution and Translocation in Normal and Cadmium-Exposed Plants. , 1991, Plant physiology.

[26]  K. Padmaja,et al.  Phytotoxicity of cadmium ions on germinating seedlings of mung bean (Phaseolus vulgaris): Involvement of lipid peroxides in chlorphyll degradation , 1992 .

[27]  R. Finch,et al.  Salinity, oxidative stress and antioxidant responses in shoot cultures of rice , 1997 .

[28]  K. Asada,et al.  Ascorbate Peroxidase in Tea Leaves: Occurrence of Two Isozymes and the Differences in Their Enzymatic and Molecular Properties , 1989 .

[29]  O. Suzuki,et al.  Molecular Cloning and Functional Characterization of Rat Δ-6 Fatty Acid Desaturase , 1999 .

[30]  E. Grill,et al.  Phytochelatins: The Principal Heavy-Metal Complexing Peptides of Higher Plants , 1985, Science.

[31]  L. Barclay.  The cooperative antioxidant role of glutathione with a lipid-soluble and a water-soluble antioxidant during peroxidation of liposomes initiated in the aqueous phase and in the lipid phase. , 1988, The Journal of biological chemistry.

[32]  P. Colepicolo,et al.  EFFECTS OF CADMIUM ON GROWTH AND SUPEROXIDE DISMUTASE ACTIVITY OF THE MARINE MICROALGA TETRASELMIS GRACILIS (PRASINOPHYCEAE) 1 , 1996 .

[33]  R. Edwards.  Characterisation of glutathione transferases and glutathione peroxidases in pea (Pisum sativum) , 1996 .

[34]  R. Wise,et al.  Chilling-enhanced photooxidation : evidence for the role of singlet oxygen and superoxide in the breakdown of pigments and endogenous antioxidants. , 1987, Plant physiology.

[35]  M. Benavides,et al.  Effect of heavy metal ion excess on sunflower leaves: evidence for involvement of oxidative stress , 1996 .

[36]  C. Foyer,et al.  Protection against oxygen radicals: an important defence mechanism studied in transgenic plants , 1994 .

[37]  A. Baker,et al.  Cadmium tolerance and toxicity, oxygen radical processes and molecular damage in cadmium‐tolerant and cadmium‐sensitive clones of Holcus lanatus L. , 1992 .

[38]  C. D. de Vos,et al.  Glutathione Depletion Due to Copper-Induced Phytochelatin Synthesis Causes Oxidative Stress in Silene cucubalus. , 1992, Plant physiology.