Correlative Imaging of the Rhizosphere ─ A Multimethod Workflow for Targeted Mapping of Chemical Gradients

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

  • Eva Lippold
  • Steffen Schlüter
  • Müller, Carsten W.
  • Carmen Höschen
  • Gertraud Harrington
  • Rüdiger Kilian
  • Martina I. Gocke
  • Eva Lehndorff
  • Robert Mikutta
  • Doris Vetterlein

Examining in situ processes in the soil rhizosphere requires spatial information on physical and chemical properties under undisturbed conditions. We developed a correlative imaging workflow for targeted sampling of roots in their three-dimensional (3D) context and assessed the imprint of roots on chemical properties of the root-soil contact zone at micrometer to millimeter scale. Maize (Zea mays) was grown in 15N-labeled soil columns and pulse-labeled with 13CO2 to visualize the spatial distribution of carbon inputs and nitrogen uptake together with the redistribution of other elements. Soil columns were scanned by X-ray computed tomography (X-ray CT) at low resolution (45 μm) to enable image-guided subsampling of specific root segments. Resin-embedded subsamples were then analyzed by X-ray CT at high resolution (10 μm) for their 3D structure and chemical gradients around roots using micro-X-ray fluorescence spectroscopy (μXRF), nanoscale secondary ion mass spectrometry (NanoSIMS), and laser-ablation isotope ratio mass spectrometry (LA-IRMS). Concentration gradients, particularly of calcium and sulfur, with different spatial extents could be identified by μXRF. NanoSIMS and LA-IRMS detected the release of 13C into soil up to a distance of 100 μm from the root surface, whereas 15N accumulated preferentially in the root cells. We conclude that combining targeted sampling of the soil-root system and correlative microscopy opens new avenues for unraveling rhizosphere processes in situ.

OriginalsprogEngelsk
TidsskriftEnvironmental Science and Technology
Vol/bind57
Udgave nummer3
Sider (fra-til)1538–1549
Antal sider12
ISSN0013-936X
DOI
StatusUdgivet - 2023

Bibliografisk note

Publisher Copyright:
© 2023 The Authors. Published by American Chemical Society.

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