Cadmium effects on embryo growth of pea seeds during germination: Investigation of the mechanisms of interference of the heavy metal with protein mobilization-related factors.

This work aims to give more insight into mechanisms of action of cadmium (Cd) on germinating pea seeds (Pisum sativum L. var. douce province), specifically the different ways by which Cd cations may interfere with the principal factors involved during germination process, notably storage proteins mobilization, amino acids freeing and proteolytic activities.

Protective role of exogenous phytohormones on redox status in pea seedlings under copper stress.

The present work aims to provide insight on the role of phytohormone application in developing efficient practical defense strategies to improve plants tolerance under heavy metal contamination. For this purpose, pea (Pisum sativum L.) seeds were germinated in an aqueous solution of 200μM CuCl up to the 3rd day and then continued to germinate in the presence of distilled water (stress cessation) or were subjected to following combinations: Cu+1μM IAA and Cu+1μM GA for 3 additional days.

Effects of copper on reserve mobilization in embryo of Phaseolus vulgaris L.

The present research reports a biochemical and micro-submicroscopic analysis of copper effect on reserve mobilization during germination of Phaseolus vulgaris L. var. soisson nain hatif seeds.

Responses of proteolytic enzymes in embryonic axes of germinating bean seeds under copper stress.

The changes in protease activities in embryonic axes during the first days of bean (Phaseolus vulgaris L.) seed germination were investigated in response to copper stress. Synthetic substrates and specific protease inhibitors have been used to define qualitatively and quantitatively different catalytic classes, particularly endoproteases (EP), carboxypeptidases (CP) and aminopeptidases (AP), then identify which ones were affected in the presence of copper.

Role of the ubiquitin-proteasome pathway and some peptidases during seed germination and copper stress in bean cotyledons.

The role of the ubiquitin (Ub)-proteasome pathway and some endo- and aminopeptidases (EPs and APs, respectively) was studied in cotyledons of germinating bean seeds (Phaseolus vulgaris L.). The Ub system appeared to be important both in the early (3 days) and late (9 days) phases of germination.

Proteolytic activities in Phaseolus vulgaris cotyledons under copper stress.

The changes in the protease activities of bean cotyledons were investigated in response to copper stress. Assays using synthetic substrates and specific protease inhibitors followed by activity measurements and electrophoresis analysis allowed to study the classes of enzymes involved in the storage protein mobilization during the germination of bean (Phaseolus vulgaris L) seeds, and then identify which ones were affected in the presence of 200 μM CuCl2 in the imbibition medium. Copper treatment affected embryo growth and total protease activity.

RETRACTED: Redox regulation of the glutathione reductase/iso-glutaredoxin system in germinating pea seed exposed to cadmium.

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Copper excess impairs mobilization of storage proteins in bean cotyledons.

Germination represents a limiting stage of plant life cycle. One of the underlying metabolic activities following imbibition of seed is the reserve mobilization. Seeds of bean (Phaseolus vulgaris L.

Oxidative damage and redox change in pea seeds treated with cadmium.

Pea seeds (Pisum sativum L.) were germinated by soaking in distilled water or 5mM CdCl2 for 5 days. The relationships among Cd treatment, germination rate, embryonic axis growth, NAD(P)H levels and NAD(P)H oxidase activities in mitochondrial and peroxisomal fractions of cotyledons and embryonic axis were investigated.

NAD pattern and NADH oxidase activity in pea (Pisum sativum L.) under cadmium toxicity.

Seeds of pea (Pisum sativum L.) were germinated for 5 days by soaking in distilled water or 5 mM cadmium chloride. Compared to the control, cadmium (Cd) caused a reduction in percent germination and embryo growth.

Effect of cadmium on resumption of respiration in cotyledons of germinating pea seeds.

Pea seeds (Pisum sativum L.) were germinated by soaking in H2O or 5 mM CdCl2 during a 5-day period. Enzyme activities involved in respiratory metabolism were studied in cotyledons.

Cadmium affects the glutathione/glutaredoxin system in germinating pea seeds.

The aim of this work was to investigate the effects of cadmium (Cd) on thiol and especially glutathione (GSH)-dependent reactions (glutathione content, glutaredoxin (Grx) content and activity, "glutathione" peroxidase (Gpx) activity, and glutathione reductase (GR) activity) in germinating pea seeds. Under Cd stress conditions, the overall activity as well as more specifically the expression of Grx C4 and Grx S12 increased. On the contrary, when incubated with Cd ions in vitro, the disulfide reductase activity of both isoforms was drastically inhibited.

Cadmium induced mitochondrial redox changes in germinating pea seed.

Mitochondria play an essential role in producing the energy required for seedling growth following imbibition. Heavy metals, such as cadmium impair mitochondrial functioning in part by altering redox regulation. The activities of two protein redox systems present in mitochondria, thioredoxin (Trx) and glutaredoxin (Grx), were analysed in the cotyledons and embryo of pea (Pisum sativum L.

Protein and peroxidase modulations in sunflower seedlings (Helianthus annuus L.) treated with a toxic amount of aluminium.

The aim of this study is to investigate the effect of aluminium treatment on peroxidases activities and protein content in both soluble and cell-wall-bound fractions of sunflower leaves, stems and roots. Fourteen-day-old seedlings, grown in a nutrient solution, were exposed to a toxic amount of aluminium (500 μM AlNO(3)) for 72 h. Under stress conditions, biomass production, root length and leaf expansion were significantly reduced.

Cadmium impairs mineral and carbohydrate mobilization during the germination of bean seeds.

The germination rate, mineral (Ca, Fe, K, Mn) and carbohydrate (starch, soluble sugars, sucrose, glucose, fructose) contents and hydrolase activities in cotyledons and embryonic axes of bean seeds subjected to cadmium stress were investigated. Compared to the control, Cd caused a reduction in germination percent, embryo growth and in distribution of biomass, mineral and sugars between cotyledon and embryonic axis and inhibited the activities of alpha-amylase and invertases: soluble acid (INV-AS), soluble neutral (INV-NS), cell wall bound acid (INV-AW). Moreover, the solute leakage into the germination medium was also used as bioindicator parameter to evaluate the toxicity of cadmium accumulation, which increased in different tissues of germinating seeds in the duration of treatment and provoked nutrient loss and, thereby, electrical conductivity enhancement in the imbibition medium.

Copper affects the cotyledonary carbohydrate status during the germination of bean seed.

Seeds of bean (Phaseolus vulgaris L.) were germinated by soaking in distilled water or copper chloride solution. The relationships among copper excess treatment, germination rate, dry weight, sugar contents, and carbohydrase activities in cotyledon were investigated.

Expression of stress-related genes in tomato plants exposed to arsenic and chromium in nutrient solution.

The molecular responses of hydroponically cultivated tomato plants to As(V) or Cr(VI) were assessed by transcript accumulation analysis of genes coding for products potentially involved in heavy metal tolerance. A quantitative real-time PCR experiment was performed with Hsp90-1, MT2- and GR1-like protein genes using RNA isolated from tomato roots or shoots treated for 24h with As(V) or Cr(VI) at concentrations ranging from 80 to 640 microM. Both transient metallic treatments induced Hsp90-1 transcript accumulation in tomato plants.

Respiratory metabolism in the embryonic axis of germinating pea seed exposed to cadmium.

Seeds of pea (Pisum sativum L.) were germinated for 5d by soaking in distilled water or 5mM cadmium nitrate. The relationships among cadmium stress, germination rate, changes in respiratory enzyme activities and carbohydrates mobilization were studied.

Aluminum mediates compositional alterations of polar lipid classes in maize seedlings.

Changes in lipid composition were investigated on maize roots and shoots under aluminum stress. After 4d exposure to 100 microM Al, root growth was inhibited while shoot growth was not affected. In roots, the decrease of the DBI (double bond index) of total fatty acids may signal a decrease in membrane fluidity.

[Biochemical changes associated with cadmium and copper stress in germinating pea seeds (Pisum sativum L.)].

Seeds of pea (Pisum sativum L.) were germinated for four days over two sheets of filter paper moistened with H2O (control) and 5 mM Cd(NO3)2 or CuSO4 (treated). The relationship between heavy-metal stress and breakdown of storage compounds was studied.

Effects of cadmium and copper on antioxidant capacities, lignification and auxin degradation in leaves of pea (Pisum sativum L.) seedlings.

Twelve-day-old seedlings of pea were treated for four days by 20 and 100 microM of Cd(NO3)2 or CuSO4. In leaves, all treatments caused an increase in the lipoperoxidation product rate. However, 20 microM of Cu did not affect the growth.

Effects of cadmium and copper on peroxidase, NADH oxidase and IAA oxidase activities in cell wall, soluble and microsomal membrane fractions of pea roots.

Twelve-day-old seedlings of pea (Pisum sativum L.) that were treated for 4 days by 20 and 100 micromol/l Cd(NO3)2 or CuSO4 showed a growth reduction in all organs. From root protein extracts, the activities of guaiacol peroxidase (GPX; EC 1.

Changes in antioxidant and lignifying enzyme activities in sunflower roots (Helianthus annuus L.) stressed with copper excess.

Treatment with 50 microM CuSO4 for five days caused significant decrease in dry-matter production and protein level of ten-day-old sunflower seedling roots. An increase of lipoperoxidation product rate was also observed. The involvement of some enzyme activities in the sunflower root defence against Cu-induced oxidative stress was studied.