Responses of Antioxidants to Paraquat in Pea Leaves (Relationships to Resistance)

Differnential sensitivity to the oxidant paraquat was observed in pea (Pisum sativum L.) based on cultivar and leaf age. To assess contributions of inductive responses of the antioxidant enzymes in short-term resistance to oxidative damage, activities of glutathione reductase (GR), superoxide dismutase (SOD), and ascorbate peroxidase (APX) and transcript levels for plastidic GR, Cu,Zn SOD, and cytosolic APX were determined. Responses to paraquat exposure from three different leaf age classes of pea were studied. Resistance was correlated with leaf age, photosynthetic rates, enzyme activities, and pretreatment levels of plastid GR and plastid Cu,Zn SOD transcripts. In response to paraquat, small increases in activities of GR and APX were observed in the more resistant leaves. These changes were not reflected at the mRNA level for the plastidic GR or Cu,Zn SOD. Paraquat-mediated increases in cytosolic APX mRNA occurred in all leaf types, irrespective of resistance. Developmentally controlled mechanisms determining basal antioxidant enzyme activities, and not inductive responses, appear to be critical factors mediating short-term oxidative stress resistance.

[1]  J. Sambrook,et al.  Molecular Cloning: A Laboratory Manual , 2001 .

[2]  B. Zilinskas,et al.  Overexpression of Copper/Zinc Superoxide Dismutase in the Cytosol of Transgenic Tobacco Confers Partial Resistance to Ozone-Induced Foliar Necrosis , 1996, Plant physiology.

[3]  R. Last,et al.  Differential Accumulation of Antioxidant mRNAs in Arabidopsis thaliana Exposed to Ozone , 1995, Plant physiology.

[4]  L. Casano,et al.  Sensitivity of Superoxide Dismutase Transcript Levels and Activities to Oxidative Stress Is Lower in Mature-Senescent Than in Young Barley Leaves , 1994, Plant physiology.

[5]  W. Van Camp,et al.  Ozone, Sulfur Dioxide, and Ultraviolet B Have Similar Effects on mRNA Accumulation of Antioxidant Genes in Nicotiana plumbaginifolia L , 1994, Plant physiology.

[6]  A. Hausladen,et al.  Purification and Characterization of Glutathione Reductase Isozymes Specific for the State of Cold Hardiness of Red Spruce , 1994, Plant physiology.

[7]  A. Hausladen,et al.  Cold-Hardiness-Specific Glutathione Reductase Isozymes in Red Spruce (Thermal Dependence of Kinetic Parameters and Possible Regulatory Mechanisms) , 1994, Plant physiology.

[8]  K. Denby,et al.  Carbon Catabolite Repression Regulates Glyoxylate Cycle Gene Expression in Cucumber. , 1994, The Plant cell.

[9]  R. Mittler,et al.  Regulation of pea cytosolic ascorbate peroxidase and other antioxidant enzymes during the progression of drought stress and following recovery from drought. , 1994, The Plant journal : for cell and molecular biology.

[10]  D. Inzé,et al.  Elevated Levels of Superoxide Dismutase Protect Transgenic Plants Against Ozone Damage , 1994, Bio/Technology.

[11]  Christine H. Foyer,et al.  Causes of Photooxidative Stress and Amelioration of Defense Systems in Plants , 1993 .

[12]  J. Gressel,et al.  Developmental Variability of Photooxidative Stress Tolerance in Paraquat-Resistant Conyza , 1993, Plant physiology.

[13]  M. May,et al.  Oxidative Stimulation of Glutathione Synthesis in Arabidopsis thaliana Suspension Cultures , 1993, Plant physiology.

[14]  R. Mittler,et al.  Detection of ascorbate peroxidase activity in native gels by inhibition of the ascorbate-dependent reduction of nitroblue tetrazolium. , 1993, Analytical biochemistry.

[15]  A. Holaday,et al.  Increased resistance to oxidative stress in transgenic plants that overexpress chloroplastic Cu/Zn superoxide dismutase. , 1993, Proceedings of the National Academy of Sciences of the United States of America.

[16]  J. L. Hess,et al.  Purification of Multiple Forms of Glutathione Reductase from Pea (Pisum sativum L.) Seedlings and Enzyme Levels in Ozone-Fumigated Pea Leaves. , 1992, Plant physiology.

[17]  W. Van Camp,et al.  Differential regulation of superoxide dismutases in plants exposed to environmental stress. , 1991, The Plant cell.

[18]  M. Aono,et al.  Resistance to active oxygen toxicity of transgenic nicotiana tabacum that expresses the gene for glutathione reductase from escherichia coli , 1991 .

[19]  R. Dhindsa,et al.  Drought Tolerance in Two Mosses: Correlated with Enzymatic Defence Against Lipid Peroxidation , 1981 .

[20]  M. M. Bradford.  A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. , 1976, Analytical biochemistry.

[21]  K. Asada,et al.  Initiation of aerobic oxidation of sulfite by illuminated spinach chloroplasts. , 1973, European journal of biochemistry.

[22]  I. Fridovich,et al.  Superoxide dismutase: improved assays and an assay applicable to acrylamide gels. , 1971, Analytical biochemistry.

[23]  C. Cramer,et al.  Physiological, Biochemical and Molecular Effects of Sulfur Dioxide , 1996 .

[24]  J. G. Scandalios.  Molecular biology of superoxide dismutase , 1994 .

[25]  M. Aono,et al.  Enhanced Tolerance to Photooxidative Stress of Transgenic Nicotiana tabacum with High Chloroplastic Glutathione Reductase Activity , 1993 .

[26]  J. G. Scandalios,et al.  Differential response of maize catalases and superoxide dismutases to the photoactivated fungal toxin cercosporin. , 1992, The Plant journal : for cell and molecular biology.

[27]  W. Zipfel,et al.  The Basis for Different Sensitivities of Photosynthesis to SO2 in Two Cultivars of Pea , 1987 .

[28]  A. Dodge,et al.  Chloroplast superoxide and hydrogen peroxide scavenging systems from pea leaves: seasonal variations. , 1987 .

[29]  K. Asada,et al.  Purification of ascorbate peroxidase in spinach chloroplasts; its inactivation in ascorbate-depleted medium and reactivation by monodehydroascorbate radical , 1987 .