Redox biology response in germinating Phaseolus vulgaris seeds exposed to copper: Evidence for differential redox buffering in seedlings and cotyledon.

In agriculture, heavy metal contamination of soil interferes with processes associated with plant growth, development and productivity. Here, we describe oxidative and redox changes, and deleterious injury within cotyledons and seedlings caused by exposure of germinating (Phaseolus vulgaris L. var.

Cadmium-induced changes in antioxidative systems and differentiation in roots of contrasted Medicago truncatula lines.

Defense pathways and stress responses induced under Cd stress were illustrated in roots of hydroponically grown Medicago truncatula seedlings. Actually, the ascorbate-glutathione and antioxidative system, secondary metabolism events including peroxidases, phenolic compounds, and lignification launching, and developmental modifications were described. Cd (100 μM) initially increased reactive oxygen species, enhanced antioxidative (total SOD, CAT, and PRX) and ascorbate-glutathione-related metabolism enzymes (APX and MDAR), except in A17 and TN1.

Synergistic health effects between chemical pollutants and electromagnetic fields.

Humans and ecosystems are exposed to highly variable and unknown cocktail of chemicals and radiations. Although individual chemicals are typically present at low concentrations, they can interact with each other resulting in additive or potentially synergistic mixture effects. This was also observed with products obtained by radiation actions such as sunlight or electromagnetic fields that can change the effects of chemicals, such as pesticides, and metal trace elements on health.

Effect of cadmium pollution on mobilization of embryo reserves in seedlings of six contrasted Medicago truncatula lines.

Six Medicago truncatula genotypes differing in cadmium susceptibility were used to test the effect of this heavy metal on mineral, carbohydrate and amino acid supply in growing radicles. Cadmium treatment caused alteration of macronutrient (Ca and K), microelement (Fe, Zn and Cu), carbohydrate (total soluble sugars (TSS), glucose, fructose and sucrose) and free amino acid (FAAS) accumulations. These mobilization changes differed in the tested genotypes.

Toxicity of sulcotrione and grape marc on Vicia faba cells.

The cell toxicity of sulcotrione, a selective triketone herbicide, was evaluated on Vicia faba. Sulcotrione, trademark Mikado, grape marc, and mixtures of sulcotrione or Mikado with grape marc induced cell death. Addition of grape marc to either sulcotrione or Mikado enhanced cell death, especially with Mikado.

Oxidative injury and antioxidant genes regulation in cadmium-exposed radicles of six contrasted Medicago truncatula genotypes.

Oxidative disorders were triggered in the presence of Cd toxicity in early seedling growth of six Medicago truncatula genotypes. Interactions between root growth inhibition, cadmium uptake, as well as the occurrence of oxidative injury suggest differential responses of the genotypes, with susceptible or tolerant accessions. ROS enhancement was observed in situ and H₂O₂ content was measured, that did not seem related to tolerance or susceptibility.

Concentration of antioxidant polyphenols from Thymus capitatus extracts by membrane process technology.

Thymus capitatus is a Mediterranean plant characterized by its antioxidant polyphenols of which the most known are the carnosic and rosmarinic acids. In this way, this study aims to concentrate these acids by membrane processes. The thyme essential oil composition was established by capillary GC-MS and 27 components were identified representing 98.

Chemical composition and biological activities of essential oils of Pinus patula.

Essential oils isolated from needles of Pinus patula by hydrodistillation were analyzed by gas chromatography-flame ionization detection (GC-FID) and gas chromatography mass spectrometry (GC-MS). Thirty-eight compounds were identified, representing 98.3% of the total oil.

Copper toxicity in expanding leaves of Phaseolus vulgaris L.: antioxidant enzyme response and nutrient element uptake.

Bioaccumulation and toxicity of copper (CuSO4) were assessed in expanding leaves of 14-day-old bean seedlings. CuSO4 was administrated in the growth medium for three days and changes in the activities of the antioxidant enzymes guaiacol peroxidase (GPX) and catalase (CAT), and in the H2O2 production and mineral element contents were measured. Copper accumulated in exposed plants caused severe symptoms such as chlorosis and necrosis as well as a dramatic reduction in dry weight production.

Cupric stress induces oxidative damage marked by accumulation of H2O2 and changes to chloroplast ultrastructure in primary leaves of beans ( Phaseolus vulgaris L.).

The effect of copper excess (CuSO 4 ) on lipid peroxidation, H2O2 content, and antioxidative enzyme activities was studied in primary leaves of bean seedlings. Fourteen-day-old bean seedlings were cultured in a nutrient solution containing Cu 2+ at various concentrations (50 and 75 microM) for 3 days. Excess of copper significantly increased malondialdehyde content and endogenous H2O2 .

Cell wall accumulation of cu ions and modulation of lignifying enzymes in primary leaves of bean seedlings exposed to excess copper.

Copper is both a nutrient and an environmental toxin that is taken up by plants. In order to determine the subcellular localization of copper and to assess the resulting metabolic changes, we exposed 14-day-old bean seedlings to nutrient solutions containing varying concentrations of Cu(2+) ions for 3 days. Biochemical analyses revealed that the cell wall was the major site of Cu(2+) accumulation in the leaves of treated plants.

Membrane damage and solute leakage from germinating pea seed under cadmium stress.

Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated.

Structural changes of cell wall and lignifying enzymes modulations in bean roots in response to copper stress.

Fourteen-day-old bean seedlings were cultured in nutrient solution containing Cu(2+) ions at various concentrations (50 and 75 microM of CuSO(4)) for 3 days. This excess of copper induced a reduction in the water volume absorbed by the plants. Moreover, this reduction was accompanied by an increase of the amount of copper taken up by the roots.

Unsuitable availability of nutrients in germinating bean embryos exposed to copper excess.

The influence of copper excess on germination rate, growth, minerals, carbohydrates, and amino acids supply in embryonic axis of bean seed was investigated. Compared to the control, Cu treatment caused a reduction in germination percent, embryo length, and accumulation of Ca, Fe, K, Mn, Zn, total soluble sugars, glucose, fructose, sucrose, and amino acids. Moreover, the nutrient concentrations, as well as the electrical conductivity were determined in the germination medium to quantify the extent of solute leakage.

Partial purification and characterization of a copper-induced anionic peroxidase of sunflower roots.

Treatment of 14-day-old sunflower seedlings with a toxic amount of copper (50 microM of CuSO(4)) during 5days caused significant increase in peroxidase activity in roots. Qualitative analysis of soluble proteins using native anionic PAGE followed by detection of peroxidase activity with guaïacol as electron donor in the presence of H(2)O(2) revealed five stimulated peroxidases, named A1, A2, A3, A4, and A5. These peroxidases had differential behavior during the period of treatment.

Effects of copper excess on growth, H2O2, production and peroxidase activities in maize seedlings (Zea mays L.).

Ten day old mays seedlings (Zea mays L., var. Aligreen) cultured in hydroponic medium were treated by toxic amounts of copper (50 and 100 microM of CuSO4) during seven days.