Cadmium and Copper Uptake and Translocation in Five Willow (SalixL.) Species

Abstract

The efficacy for phytoremediation of five willow species was tested by experimental copper and cadmium uptake in a greenhouse hydroponic system. Five treatments included two concentrations (5 and 25 microM for each metal) and a control. Metal concentrations in solution as well as solution uptake were monitored. Metal resistance was assessed through effects on the dry weight of roots and shoots. The willow species tested were generally resistant of increased Cu and Cd content. Metal accumulation was found in all plant organs of all species. Growth and transpiration were not decreased by 5 microM of copper and 25 microM of cadmium in the solution for most species. 25 microM copper caused injury and reduced the dry weight for all species after 21 d. Salix nigra was highly resistant of both Cu and Cd and accumulated more metals than other species. Future field study should be conducted to confirm the findings and feasibility of the phytoremediation technology using those species.

Toxicity assessment of contaminated soils from a mining area in Northeast Italy by using lipid peroxidation assay

“…Compared to control, heavy metals induced oxidative stress in willows was evident from the increased lipid peroxidation in roots, stems and leaves, indicating an enhanced MDA production, with MDA increasing in leaves in comparison to roots and stems. This is in agreement with data reported by Kuzovkina et al (2004) and Ali et al (2003). A maximum concentration of 41.64 μM MDA in S. purpurea leaves collected from site 1 and 30.78 μM in the roots of the same species from site 3 was observed, indicating severe cell injury (Maleci, 2011, personal communication).…”

Variation in copper and zinc tolerance and accumulation in 12 willow clones: implications for phytoextraction

“…3 indicate that clones accumulated higher percentages of Cu in the roots than in aerial parts, which is in agreement with previous reports (Ali et al, 2003;Kuzovkina et al, 2004;Borghi et al, 2007;Castiglione et al, 2009). The distribution pattern of Cu in plant parts was ranked in the order of roots>stems>leaves.…”

“…Low values of leaf and shoot TFs in the Cu treatments suggest that all clones had a poorer ability to translocate Cu from the roots to the leaves/ shoots (including stems). This low mobility of Cu in the Salicaceae family has also been confirmed in previous studies (Punshon et al, 1995;Kuzovkina et al, 2004;Castiglione et al, 2009). The low translocation of Cu to the shoots is probably due to the roots having a strong affinity for Cu (Sahi et al, 2007), as Cu is confined to the root surface or is adsorbed by the apoplast (Kuzovkina et al, 2004); further, Cu binds to the carboxylic groups of pectins and polygalacturonic acids in the roots (Borghi et al, 2007).…”

“…Most results of willow screening have shown that the tolerance and uptake of heavy metals depend strongly on species and clones (Punshon et al, 1995;Dos Santos Utmazian et al, 2007;Zacchini et al, 2009;Zhivotovsky et al, 2010). Salix comprises about 450 species as well as a large number of willow clones produced through breeding projects worldwide, which together provide a large number of plants to be screened for phytoremediation (Kuzovkina et al, 2004;Kuzovkina and Quigley, 2005). Owing to the high genetic variability in Salix, the use of clone selection has been proposed to find those best suited for phytoremediation purposes (Zalesny et al, 2007;Zalesny and Bauer, 2007b).…”

“…Many studies have investigated the metal accumulation potential of Salix to identify prospective phytoremediation species/clones through carefully controlled hydroponic screenings (Punshon et al, 1995;Watson et al, 2003;Kuzovkina et al, 2004;Wang and Greger, 2004;Dos Santos Utmazian et al, 2007;Purdy and Smart, 2008;Mleczek et al, 2010;Zhivotovsky et al, 2010). As a rapid screening technology, hydroponic screening reduces the time and space required in comparison with other methods, and is especially suitable for high-throughput screening to evaluate large amounts of plant materials for phytoremediation (Dos Santos Utmazian et al, 2007).…”