Amanda dos Santos Augusto

Lycopersicon esculentum submitted to Cd-stressful conditions in nutrition solution: Nutrient contents and translocation.

The increasing number of cases on soil contamination by heavy metals has affected crop yields, besides representing an imminent risk to food. Some of these contaminants, such as cadmium, are very similar to micronutrients and thus more easily absorbed by the plants. This study assessed the effect of increasing amounts of cadmium on the content and translocation of micro and macronutrients in tomato. Tomatoes were grown in Clarks nutrient solution and subjected to increasing levels of Cd: 0, 0.025, 0.1, 0.5 and 1.0mg L(-1). The plants contaminated by cadmium had a maximum reduction in the aerial part compared to the control of: 2.25g kg(-1), 2.80g kg(-1), 18.93mg kg(-1) and 14.15mg kg(-1) for K, Ca, Mn and Zn, respectively. In other parts of the tomato were reduced from 2.3g kg(-1) K in fruits and 280.5mg kg(-1) of Mn in the roots. In addition to changes in the levels of some nutrients, the restricted Cd translocation in 1.15 percent P and 2.8 percent Cu to shoots compared to control, but did not affect the translocation of K, Ca, Mg and Zn.

Effects of Lead on the Content, Accumulation, and Translocation of Nutrients in Bean Plant Cultivated in Nutritive Solution

Increasing contents of lead (Pb; from 0 to 10 mg L−1) as contaminant were added in Clarks nutritive solution to evaluate the effects on content, accumulation, and translocation of macronutrients [phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S)] and micronutrients [copper (Cu), manganese (Mn), zinc (Zn), and iron (Fe)] in different parts of the bean plant (Phaseolus vulgaris L.). Experiments were built using an entirely randomized statistical arrangement and measurements were performed after 60 days of exposure to Pb. The contents of almost all nutrients decreased when Pb was added, except for P in root, Mg in fruits, and S in root and fruits. Reduction in accumulation of all nutrients in the three parts of plants was determined, and an increase in the translocation index was observed for the following nutrients: Mg and Zn in fruits and S in fruits and leaves. For the remaining nutrients, the translocation index diminished.

Effects of Cadmium and Lead on Plant Growth and Content of Heavy Metals in Arugula Cultivated in Nutritive Solution

A greenhouse assay using an arugula (Eruca sativa L.) hydroponics system was carried out to evaluate the following effects of increasing amounts of cadmium and lead in nutritive solution: (a) production; (b) translocation of cadmium (Cd) and lead (Pb) throughout the plants; (c) possible interactions of Cd and Pb with other mineral elements, transition metals, essential to plants; (d) tolerance limits to Cd and Pb with regard to production; and (e) chelating interaction of Cd and Pb with root substances. The absorption of Cd and Pb increased with increasing dosages in solution. Roots accumulated larger amounts of metals than shoots. Plants develop better with less than 0.025 mg L−1 of Cd, with a damaging Cd concentration of 1 mg L−1. The tolerable Pb concentration was up to 10 mg L−1. Cadmium and Pb translocate poorly in plants and their deleterious effect is due to the deposit of very stable chelates in roots.

Stress Induced by Heavy Metals Cd and Pb in Bean (Phaseolus Vulgaris L.) Grown in Nutrient Solution

The increasing number of cases of soil contamination by heavy metals has affected crop yields, and represents an imminent risk to food. Some of these contaminants, such as cadmium (Cd) and lead (Pb), are very similar to micronutrients, and thus can be absorbed by plants. This study evaluated the translocation of increasing amounts of cadmium and lead and the effects of these metals in the production of beans. Bean plants were grown in nutrient solution Clark and subjected to increasing levels of Cd (from 0 to 0.5 mg L−1) and Pb (from 0 to 10 mg L−1). Cadmium concentration of 0.1 mg L−1 translocated 39.8% to the shoot, and dry matter production was reduced by 45% in shoots and 80% in roots, compared to the control treatment. Lead showed impaired movement in the plant, however the concentration of 1.0 mg L−1 was observed in 5.7% of metal translocation to the leaves. The concentration of 10 mg L−1 Pb reduced dry matter production of roots and shoots in 83% and 76%, respectively, compared to the control treatment.

Bioaccumulation of Heavy Metals inBrassica juncea: Relationship of Toxicity with Essential Elements

With the objective of evaluating the effect of cadmium and lead in the culture of mustard (Brassica juncea) and its relationship with the plant macroand micronutrients, mustard plants were grown in Clark nutrient solution and exposed to increasing doses of Cd and Pb. P contents were determined by colorimetry, S by turbidimetry and K, Ca, Mg, Fe, Cu, Mn and Zn of the dry matter (MSPA) and root (MSR) were determined using flame atomic absorption spectrophotometry. Cd negatively influenced the levels of nutrients in mustard plants, except for Cu in leaves and roots, Fe in the leaves and Mn in the root. Contamination by Pb decreased the levels of all the plant nutrients, except Ca in roots and leaves with the highest dose of Pb, and Mg, P, Cu, Fe and Zn in the root. The influence of contamination of Cd and Pb in nutrients caused severe reduction in dry matter production of mustard plant.

Avaliação dos efeitos tóxicos de Cd e Pb na cultura da mostarda (Brassica juncea)

With the objective of evaluating the effect of cadmium (Cd) and lead (Pb) in the culture of mustard (Brassica juncea) and its relationship with plant development, levels, accumulation and translocation in roots and shoots, mustard plants were grown in Clark nutrient solution and subjected to increasing doses of Cd (0.00; 0.25; 1.00; 5.00 and 10.00 mg.L-1) and Pb (0.00; 2.50; 10.00; 50.00 and 100.00 mg.L-1). Cd showed a significant translocation into the plant, which is due to the formation of a complex between the chemical species and phytochelatin; the low translocation of Pb and deleterious effects are due to root deposits of Pb stable chelates.