Abstract
Trees that accumulate metals are important plants for restoring contaminated soil because of their high biomass. In our previous study, we discovered that Salix miyabeana has the capability to take up high levels of Cd, and identified the several accumulation sites of the endogenous metals in the leaf parts of plants. To analyze the detailed localization of Cd in apoplastic and symplastic compartments in S. miyabeana, synchrotron radiation-based micro X-ray fluorescence (SR-μ-XRF) analysis and micro X-ray absorption near edge structure (μ-XANES) measurements were performed on beam line 37XU of the SPring-8 (Hyogo, Japan). The two-dimensional metal distribution of segments of young stems was obtained by μ-XRF with approximately 2 μm(2) X-ray beams and showed the predominant localization of Cd in the apoplastic region. μ-XANES analyses suggest that the apoplastic detoxification of Cd in willow depends on Cd-oxygen, but not on Cd-sulfur, interaction. S. miyabeana growing near an old mining site in Japan was then examined to evaluate the metal accumulating ability of this plant in the field. The metal concentration in the leaves of the plants was compared to that in the soil and enrichment factors (EFs) were calculated for Cu, Zn, Cd and Pb. Results showed efficient removal of Cd and Zn from the contaminated sites by the willow plants. In order to discuss the combined and long-term effect of multiple heavy metals on S. miyabeana grown in soil, variable-pressure scanning electron microscopy fitted with energy dispersive X-ray analysis (VPSEM-EDX) and SR-μ-XRF was used to characterize the serration of leaves. The combination of 2D elemental images revealed metal accumulation in the tip cells in serrations without any exudation of heavy metals from the hydathodes.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.