Elemental mapping using PIXE shows the main pathway of nickel movement is principally symplastic within the fruit of the hyperaccumulator Stackhousia tryonii

Naveen P Bhatia; Ivo Orlic; Rainer Siegele; Nanjappa Ashwath; Alan J M Baker; Kerry B Walsh

doi:10.1046/j.1469-8137.2003.00912.x

Elemental mapping using PIXE shows the main pathway of nickel movement is principally symplastic within the fruit of the hyperaccumulator Stackhousia tryonii

New Phytol. 2003 Dec;160(3):479-488. doi: 10.1046/j.1469-8137.2003.00912.x. Epub 2003 Nov 6.

Authors

Naveen P Bhatia¹, Ivo Orlic², Rainer Siegele², Nanjappa Ashwath¹, Alan J M Baker³, Kerry B Walsh¹

Affiliations

¹ Primary Industries Research Centre, School of Biological and Environmental Sciences, Central Queensland University, Rockhampton, Qld 4702, Australia.
² Physics Division, Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia.
³ School of Botany, The University of Melbourne, Victoria 3010, Australia.

PMID: 33873657
DOI: 10.1046/j.1469-8137.2003.00912.x

Abstract

• Metal concentrations within reproductive tissues of metallophytes are rarely reported. Here, the spatial distribution of nickel (Ni) within the fruits (seeds) of the Ni hyperaccumulator Stackhousia tryonii was investigated. • Two microanalytical techniques, energy dispersive x-ray spectrometry (EDXS) and nuclear microprobe (micro-proton-induced x-ray emission spectrometry; micro-PIXE) were employed for qualitative and quantitative assessment, respectively, of localized Ni, within the fruits of S. tryonii. The results were compared with quantitative analysis made using inductively coupled plasma-optical emission spectrometry (ICP-OES). • Nickel analysis made using micro-PIXE was consistent with bulk (ICP-OES) analysis (at 1800 µg g^-1 d. wt), however, a beam resolution of approx. 2 × 2 µm² allowed tissue localization. Nickel was partitioned to the fruit wall (pericarp) (4433 µg g^-1 ), while endospermic and cotyledonary tissues possessed little Ni (309 and 182 µg g^-1 d. wt, respectively). • This distribution is consistent with the interpretation that principal pathway of Ni movement within the fruit is symplastic rather than apoplastic (as the filial generation lacks symplastic connection with the parent).

Keywords: elemental mapping; metal hyperaccumulation; micro-PIXE; nickel (Ni); nuclear microprobe analysis; quantitative imaging; spot analysis; x-ray analysis.