Arsenic hyperaccumulation and localization in the pinnule and stipe tissues of the gold-dust fern (Pityrogramma calomelanos (L.) Link var. austroamericana (Domin) Farw.) using quantitative micro-PIXE spectroscopy

Abstract

Arsenic hyperaccumulation and localization in the pinnule and stipe tissues of the gold-dust fern (Pityrogramma calomelanos (L.) Link var. austroamericana (Domin) Farw.) using quantitative micro-PIXE spectroscopy Abstract Spatial distribution patterns of arsenic (As) in the tissues of a lesser-known As hyperaccumulating fern Pityrogramma calomelanos (L.) Link var. austroamericana (Domin) Farw. (Pteridaceae) have been studied. Quantitative micro-proton-induced X-ray emission (micro-PIXE) spectroscopy was employed to examine As localization in pinnule and stipe crosssections of this species. In addition, As hyperaccumulation status of P. calomelanos var. austroamericana was compared with the well-known As hyperaccumulating fern Pteris vittata L. Both species were grown in pots under controlled conditions and exposed to four levels of As (0-500 mg As kg −1 ) for 20 weeks. Pityrogramma calomelanos var. austroamericana accumulated up to 16 415 mg As kg −1 dry weight (DW), however, phytotoxicity symptoms such as necrotic pinnule tips and margins, appeared in fronds with concentrations >3,008 mg As kg −1 DW. Arsenic was readily translocated to fronds, with concentrations up to 75 times greater in fronds than in roots. Quantitative elemental maps of As generated using micro-PIXE analysis revealed that As concentrations in pinnule cross-sections were higher than in stipe cross-sections with concentrations of 3.7×10 3 and 1.6×10 3 mg As kg −1 DW, respectively (as determined by region selection analysis; RSA). In pinnules, RSA revealed variable concentrations of As, however did not resolve a clear pattern of compartmentalization across different anatomical regions. In stipe tissues, As concentrations followed the order vascular bundle > cortex > epidermis (as determined by RSA). Our results show that P. calomelanos var. austroamericana is an As hyperaccumulator and has the potential for use in phytoremediation of soils with low levels (up to 50 mg kg −1 ) of As contamination.

Mangifera indica as Bioindicator of Mercury Atmospheric Contamination in an ASGM Area in North Gorontalo Regency, Indonesia

“…The images are quantitative and stored in units of ppm [24,28]. The GeoPIXE II software package (CSIRO, Clayton, Australia) [24,29] was used to analyze the PIXE spectra and generate overlap-resolved and background-subtracted quantitative elemental maps with the Dynamic Analysis method [24,29].…”

Quantitative elemental localisation in leaves and stems of nickel hyperaccumulating shrub Hybanthusfloribundus subsp. floribundus using micro-PIXE spectroscopy

“…In the present study, micro-PIXE results as determined by RSA and QPA indicated epidermal cells in leaves as the preferential sites for Ni localisation and possible detoxification. Quantitative point analysis is derived from a single elemental profile across a selected area within an analysed image or section of the plant whereas RSA provides the average concentration for the entire anatomical region within the analysed image [29]. In this study, we consider that the two methods provide complimentary information in that QPA provides spatial resolution of the elements mapped and RSA a more accurate average concentration for the region selected.…”

“…Samples were cryo-fixed and freezedried prior to micro-PIXE investigation in order to provide an accurate representation of the spatial localisation of elements in vivo [29,15]. Briefly, after 20 weeks of exposure to respective Ni concentrations, leaf and stem material from three Ni-treated and untreated replicate plants were rinsed with deionised water; excised; hand-sectioned with a stainless steel razor blade and immediately plunged into liquid nitrogen and cryo-fixed (time lapse in the whole procedure being <10 s).…”

Soil Contamination with Metals

“…austroamericana(Domin) Farw. (Pteridaceae) can accumulate As up to 16415 ppm in fronds (Kachenko et al, 2007). Recently, Niazi et al (2011) found that gold dust fern (P. calomelanos var.…”