Analysis of trace metal distribution in plants with lab-based microscopic X-ray fluorescence imaging

Bibliographic Details
Title: Analysis of trace metal distribution in plants with lab-based microscopic X-ray fluorescence imaging
Authors: Ana Mijovilovich, Filis Morina, Syed Nadeem Bokhari, Timo Wolff, Hendrik Küpper
Source: Plant Methods, Vol 16, Iss 1, Pp 1-21 (2020)
Publisher Information: BMC, 2020.
Publication Year: 2020
Collection: LCC:Plant culture
LCC:Biology (General)
Subject Terms: Micro X-ray fluorescence, Zinc, Hyperaccumulator, Micronutrients, Leaf age, Root, Plant culture, SB1-1110, Biology (General), QH301-705.5
More Details: Abstract Background Many metals are essential for plants and humans. Knowledge of metal distribution in plant tissues in vivo contributes to the understanding of physiological mechanisms of metal uptake, accumulation and sequestration. For those studies, X-rays are a non-destructive tool, especially suited to study metals in plants. Results We present microfluorescence imaging of trace elements in living plants using a customized benchtop X-ray fluorescence machine. The system was optimized by additional detector shielding to minimize stray counts, and by a custom-made measuring chamber to ensure sample integrity. Protocols of data recording and analysis were optimised to minimise artefacts. We show that Zn distribution maps of whole leaves in high resolution are easily attainable in the hyperaccumulator Noccaea caerulescens. The sensitivity of the method was further shown by analysis of micro- (Cu, Ni, Fe, Zn) and macronutrients (Ca, K) in non-hyperaccumulating crop plants (soybean roots and pepper leaves), which could be obtained in high resolution for scan areas of several millimetres. This allows to study trace metal distribution in shoots and roots with a wide overview of the object, and thus avoids making conclusions based on singular features of tiny spots. The custom-made measuring chamber with continuous humidity and air supply coupled to devices for imaging chlorophyll fluorescence kinetic measurements enabled direct correlation of element distribution with photosynthesis. Leaf samples remained vital even after 20 h of X-ray measurements. Subtle changes in some of photosynthetic parameters in response to the X-ray radiation are discussed. Conclusions We show that using an optimized benchtop machine, with protocols for measurement and quantification tailored for plant analyses, trace metal distribution can be investigated in a reliable manner in intact, living plant leaves and roots. Zinc distribution maps showed higher accumulation in the tips and the veins of young leaves compared to the mesophyll tissue, while in the older leaves the distribution was more homogeneous.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1746-4811
Relation: http://link.springer.com/article/10.1186/s13007-020-00621-5; https://doaj.org/toc/1746-4811
DOI: 10.1186/s13007-020-00621-5
Access URL: https://doaj.org/article/cde26c50ac8b433f82eb613b4ebe7976
Accession Number: edsdoj.26c50ac8b433f82eb613b4ebe7976
Database: Directory of Open Access Journals
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More Details
ISSN:17464811
DOI:10.1186/s13007-020-00621-5
Published in:Plant Methods
Language:English