Clonal Differences in Mercury Tolerance, Accumulation, and Distribution in Willow

Abstract

This study was performed to investigate mercury (Hg) tolerance, accumulation, and translocation within the genus Salix for the potential use of this plant to remediate Hg-contaminated sites. Six clones of willow (Salix spp.) were tested on tolerance to Hg by treating plants grown in solution culture with 0 to 15 microM HgCl(2). Results showed that willow had a large variation in its sensitivity to Hg. However, the accumulation and translocation of Hg to shoots was similar in the eight tested willow clones as shown by cold vapor atomic absorption spectrometry analysis when plants were treated with 0.5 microM HgCl(2) in a nutrient solution. The majority of total Hg accumulated was localized to the roots, whereas only 0.45 to 0.62% of the total Hg accumulated via roots was translocated to the shoots. Thus, the root system is the main tissue of willow that accumulates Hg and the majority of the Hg in the root system (80%) was bound in the cell wall.

Detection and Quantification of Unbound Phytochelatin 2 in Plant Extracts of Brassica napus Grown with Different Levels of Mercury

“…In fact, PCs were not detected in either sensitive or tolerant willow (Salix spp.) clones in recent reports for Hg (Wang and Greger, 2003) and other metals (Landberg and Greger, 2004).…”

Heavy metals and woody plants - biotechnologies for phytoremediation

“…In Salix spp. it was proved that the majority of the mercury is accumulated and retained in the cell wall of the roots and only a very small part is trans ferred to the shoots (Wang & Greger 2004).…”

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

“…Numerous studies have revealed a remarkable genotypic variability of the genus Salix in its ability to tolerate/accumulate heavy metals (Wang and Greger, 2004;Dos Santos Utmazian et al, 2007;Purdy and Smart, 2008;Zhivotovsky et al, 2010). 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).…”

“…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).…”