Physiological response of Cu and Cu mine tailing remediation of Paulownia fortunei (Seem) Hemsl

Abstract

The physiological responses and Cu accumulation of Paulownia fortunei (Seem) Hemsl. were studied under 15.7-157 μmol L(-1) Cu treatments in liquid culture for 14 days; the impacts of Cu concentration in the seedlings were evaluated under Cu mine tailing culture with acetic acid and EDTA treatment for 60 days. Results showed that the concentrations of Chl-a, Chl-b and Carotenoids significantly increased (p < 0.05) at 15.7-78.7 μmol L(-1)Cu treatment and significantly decreased at 157 μmol L(-1) treatment after 14 days of Cu exposure. The activities of superoxide dismutase (SOD) and catalase (CAT) significantly increased as Cu levels were enhanced and the activities of both SOD and CAT under 157 μmol L(-1) Cu stress were 2.9 and 1.9 times higher than that of control, respectively. The concentrations of proline and soluble sugars in the leaves of P. fortunei significantly increased as the Cu concentrations were elevated. Cu concentrations in roots, stems and leaves of P. fortunei increased significantly as Cu levels increased and reached 1911, 101 and 93 μg g(-1) dry weights (DW) at 157 μmol L(-1) Cu treatment, respectively. The seedlings of P. fortunei cultivated in Cu tailing experienced unsuccessful growth and loss of leaves in all treatments due to poor nutrition of the Cu tailing. The dry weight of P. fortunei increased under all the treatments of acetic acid after 60 days exposure. However, dry weight significantly decreased under both levels of EDTA. The Cu concentrations increased significantly in roots and decreased in leaves when each was treated with both concentrations of acetic acid. The Cu concentrations in the roots, stems and leaves increased significantly, and the concentrations of Cu in the stems and leaves under the treatment of 2 μmol L(-1) EDTA reached 189.5 and 763.1 μg g(-1) DW, respectively. The result indicated that SOD, CAT, proline and soluble sugars played an important role in coping with the oxidative stress of copper. Acetic acid could promote growth and EDTA at the experimental levels, which could also enhance Cu absorption and translocation into the stems and leaves of P. fortune. Furthermore, acetic acid and EDTA could be rationally utilized in Cu-contaminated soil.

Improving sustainability in the remediation of contaminated soils by the use of compost and energy valorization by Paulownia fortunei

“…The exception was Cu, which reached concentrations above the normal value of 20 mg kg -1 , even in the non-contaminated soil (maximum value of 120 mg kg -1 in V soil). The ability of this species to accumulate Cu has been previously reported by other authors (Jiang et al, 2012).…”

“…Recent studies have shown that some Paulownia species show a relatively high tolerance to the presence of high concentrations of trace elements in the soil (Jiang et al, 2012;Madejón et al, 2014). Species in the Paulownia genus are highly adaptive to a wide range of climate and soil conditions (Yadav et al, 2013), and their use has been proposed for the afforestation of semi-arid areas, given their relatively good performance even under low water irrigation regimens (García-Morote et al, 2014).…”

Effect of EDTA-assisted copper uptake on photosynthetic activity and biomass production of sweet Sorghum

“…Similar effects of copper treatments on soluble sugar contents were reported by other authors (Jiang et al 2012) but the effect of copper was very significantly enhanced by EDTA in our system. Higher soluble sugar levels can be detected after 0.1 mM CuCl 2 + 300 mM EDTA treatments in the stem which is the most important plant part in the agricultural and industrial practice.…”

Citric acid and EDTA on the growth, photosynthetic properties and heavy metal accumulation of Iris halophila Pall. cultivated in Pb mine tailings

“…Sample collection and treatment were based on the method of Jiang et al (2012). The physicochemical properties of Pb tailings were as follow: available P 8.46 mg kg À1 , available K 23.27 mg kg À1 , available N 5.075 mg kg À1 , pH (CaCl 2 ) 6.23, and Pb 706.93 mg kg À1 .…”