Comparative study of metal resistance and accumulation of lead and zinc in two poplars

Abstract

In our study, we tested two poplars, Populus beijingensis and Populus cathayana, as model species for their potential for phytoremediation by measuring changes in biomass, pigments, superoxide radicals (O2(-)), cellular ultrastructure and their ability for O2(-) quenching and heavy metal accumulation when exposed to Pb, Zn and their interaction in a hydroponic system. Exposure to Pb did not cause a significant decrease in biomass in either P. beijingensis or P. cathayana. Correspondingly, no obvious impairment in cellular organelles was observed in either species, although the former species translocated a higher fraction of Pb to its shoots than the latter. In contrast, there were significant decreases in biomass and pigment content, and serious impairments in ultrastructure in both species when exposed to either Zn alone or to a combined treatment. Under such conditions, P. beijingensis showed smaller losses of biomass and pigments but a greater ability to quench O2(-) and maintained relatively intact cellular organelles compared with P. cathayana. Under the combined stress, there were no obvious additive effects on biomass, pigments or cellular impairment, whereas synergistic effects on metal absorption and accumulation in both species were observed when compared with exposure to either alone. Thus, the attribute of synergistic uptake and translocation in both species validates their potential to remediate soil contaminated by multiple metals. Moreover, our results indicated that P. beijingensis is a better potential candidate for phytoremediation than P. cathayana, due to its greater phytoremediation efficiency as well as its higher tolerance capacity.

Co-remediation of Pb Contaminated Soils by Heat Modified Sawdust and Festuca arundinacea

“…As shown in the present study, Pb accumulated in roots and had a low translocation to shoot, which was consistent with previous conclusions 38 . Wang et al 39 and Chen et al 40 found that in different concentrations of polluted solution, Pb accumulated in roots of Salix integra and poplar, and our experimental results were consistent with this result. The first step of Pb accumulation in plants is to be absorbed by roots, which means roots play an important role in Pb resistance and accumulation.…”

Pb-Stress Induced Oxidative Stress Caused Alterations in Antioxidant Efficacy in Two Groundnut (<i>Arachis hypogaea</i> L.) Cultivars

“…Pb toxicity is reported to induce the increase of MDA in Talinum triangulare [63]. As excess of heavy metals stimulate the formation of free radicals [64]. A constitutive amount of O 2…”

Effect of Pb-Stress on Growth and Mineral Status of Two Groundnut (Arachis hypogaea L.) Cultivars

“…A reduction in total chlorophyll content during Pb supply has been noticed in cucumber [32], radish [33] Populus [34] and Vallisneria natans [35]. In the present study, the reduction of total chlorophyll content was less in cultivar K6 suggesting the tolerance of cultivar K6 compared to cultivar K9.…”