M. Ghorbanli; A. Kiapour
Abstract
Portulaca oleracea L. belongs to Portulacaceae order. From the physiological point of view, P. oleracea L., generally known as ragwed, has a very high tolerance and compatibility to the environments polluted with salts or heavy metals. It is considered as a suitable species in planting as well as in ...
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Portulaca oleracea L. belongs to Portulacaceae order. From the physiological point of view, P. oleracea L., generally known as ragwed, has a very high tolerance and compatibility to the environments polluted with salts or heavy metals. It is considered as a suitable species in planting as well as in refining soil and environment from these kinds of stresses. According to these contexts and in order to show the effects of two heavy metals, lead and copper, on malondialdehyde, proline and antioxidant enzymes activity some experiments were performed in a completely randomized design. For this purpose, plants were planted in sterile bed, leca, irrigated with Hogland nutrient solotion. Treatments included different concentrations of Pb (NO3)2 and CuSO4.5H2O (0, 10,50,100,500,1000 and 1500 µM) with three replications. After ten days of treatment, plants were harvested for experiments. According to the results, an increased absorption of lead and copper was recoreded at high concentrations compared to the control treatment. The amount of atomic absorption of these two elements in roots was more than that of shoots. Stress increased significantly at high concentrations compared to the control. The amount of proline showed a significant upward trend in both lead and copper stress as well as in both roots and shoots. Peroxidase activity showed a significant upward trend in both lead and copper stress as well as in both shoots and roots while a significant downward trend was recorded for catalase activity. In general, a higher amount of malondialdehyde, proline and peroxidase activity was obtained in root samples comperd to shoot samples, indicating the role of root as the main accumulator of heavy metals, lead and copper. The lower catalase activity in roots compared to shoots proved enzyme sensitivity towards high Pb and Cu accumulation in roots.
M. Ghorbanli; A. Kiapour
Abstract
Several defense systems are cooperating together in plants to cope with stressful situations. One of these stresses is heavy metals pollution of the plant's growing environment. In This article, the effect of different concentrations of copper was studied on photosynthetic and non-photosynthetic pigments, ...
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Several defense systems are cooperating together in plants to cope with stressful situations. One of these stresses is heavy metals pollution of the plant's growing environment. In This article, the effect of different concentrations of copper was studied on photosynthetic and non-photosynthetic pigments, non-enzymatic and enzymatic defence systems in Portulaca oleracea L. In order to show the effect of so-called heavy metal, copper, on pigments, anthocyanines, flavonoides, phenolic compounds and the activity of antioxidant enzymes some experiments were performed in a completely randomized design and statistical differences were applied at the p ≤ 0.05 level. After planting the plants with the same conditions in the sterile bed, they were nourished with Hoagland's liquid medium. The bed was then amended with graded concentrations (0, 10, 50, 100, 500, 1000 and 1500 µM) of copper salt, in the form of CuSO4.5H2O, separately as treatments and with the control group. Three replicates were maintained for each treatment and also for control groups. After ten days of applying the treatments, the plants were harvested for performing the experiments. After measuring and applying the statistical differences at the 0.05 level via SPSS software, these results were obtained: The amount of chlorophyll a and b was decreased. Amounts of carotenoides, anthocyanines, flavonoides and phenolic compounds were significantly increased. Peroxidase activity was increased and catalase activity was decreased in both shoots and roots.