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Plant and Soil

, Volume 437, Issue 1–2, pp 473–485 | Cite as

Visualization and quantification of root exudation using 14C imaging: challenges and uncertainties

  • Maire HolzEmail author
  • Mohsen Zarebanadkouki
  • Andrea Carminati
  • Yakov Kuzyakov
Methods Paper
  • 418 Downloads

Abstract

Background and aims

Root exudation is an important carbon (C) and energy source for soil microorganisms but quantifying its spatial distribution is challenging. We tested whether 14C imaging (analogue of previous autoradiography) can be used to quantitatively estimate the spatial distribution of root exudates in the rhizosphere.

Methods

First, the attenuation coefficient of 14C β rays in soil and in water was measured and expected gradients of 14C in the rhizosphere were modelled. Secondly, barley plants were pulse labelled in 14CO2 atmosphere and the origin (roots or root exudation) and locations of 14C signal in soil were detected with imaging.

Results

The attenuation coefficient of 14C was 148 cm−1 for soil and 67 cm−1 for water, corresponding to a maximum distance that 14C β rays pass through a dry soil of 0.37 mm. Based on the measured coefficients we calculated the effect of exudation intensity, root radius and root position on the imaged 14C signal. The distribution of the imaged signal was strongly affected by: a) 14C activity in the root, b) root radius, c) distance from the root surface to the imaging screen, d) amount of root exudates in the soil, and e) presence of an air gap (or a region with high porosity) between the soil and the imaging screen.

Conclusions

Neglecting the effects of these factors (a-e) may cause biases in the estimation of root exudates using 14C imaging of the rhizosphere. The 14C imaging approach should therefore be accompanied by accurate measurement of these factors and calculation of the β ray transmission through the soil.

Keywords

14C imaging Root exudation Soil-root imaging 14C attenuation 

Notes

Acknowledgements

We thank Bea Burak and Ian Dodd for kindly providing the seeds for the experiments and the Laboratory for Radioisotopes (LARI) for using their facilities. We acknowledge the DFG for funding (Projects CA 921/3-1 and KU 1184/33-1) and ev. Studienwerk Villigst for funding the position of MH. The contribution of YK was supported by the Russian Science Foundation (project No. 18-14-00362).

References

  1. Amemiya Y, Miyahara J (1988) Imaging plate illuminates many fields. Nature 336:89–90.  https://doi.org/10.1038/336089a0 CrossRefPubMedGoogle Scholar
  2. Cole JM, Nienstedt J, Spataro G, Rasbury ET, Lanzirotti A, Celestian AJ, Nilsson M, Hanson GN (2002) Phosphor imaging as a tool for in situ mapping of ppm levels of uranium and thorium in rocks and minerals. Chem Geol 193:127–136.  https://doi.org/10.1016/S0009-2541(02)00223-1 CrossRefGoogle Scholar
  3. Dennis PG, Miller AJ, Hirsch PR (2010) Are root exudates more important than other sources of rhizodeposits in structuring rhizosphere bacterial communities? FEMS Microbiol Ecol 72:313–327.  https://doi.org/10.1111/j.1574-6941.2010.00860.x CrossRefGoogle Scholar
  4. Evans RD (1955) The atomic nucleus. McGraw-Hill, New York, pp 785–793Google Scholar
  5. Fuji Photo Film Co. Ltd. (2003) Image Format Description, BAS2500 system, April, Version 1.0Google Scholar
  6. Gunina A, Kuzyakov Y (2015) Sugars in soil and sweets for microorganisms: review of origin, content, composition and fate. Soil Biol Biochem 90:87–100.  https://doi.org/10.1016/j.soilbio.2015.07.021 CrossRefGoogle Scholar
  7. Holz M, Zarebanadkouki M, Kuzyakov Y, Pausch J, Carminati A (2017) Root hairs increase rhizosphere extension and carbon input to soil. Ann Bot 121:61–69.  https://doi.org/10.1093/aob/mcx127 CrossRefPubMedCentralGoogle Scholar
  8. Johnston RF, Pickett SC, Barker DL (1990) Autoradiography using storage phosphor technology. Electrophoresis 11:355–360.  https://doi.org/10.1002/elps.1150110503 CrossRefPubMedGoogle Scholar
  9. Jones DL, Hodge A, Kuzyakov Y (2004) Plant and mycorrhizal regulation of rhizodeposition. New Phytol 163:459–480.  https://doi.org/10.1111/j.1469-8137.2004.01130.x CrossRefGoogle Scholar
  10. Landi L, Valori F, Ascher J, Renella G, Falchini L, Nannipieri P (2006) Root exudate effects on the bacterial communities, CO2 evolution, nitrogen transformations and ATP content of rhizosphere and bulk soils. Soil Biol Biochem 38:509–516CrossRefGoogle Scholar
  11. Leblans P, Vandenbroucke D, Willems P (2011) Storage phosphors for medical imaging. Materials (Basel) 4:1034–1086.  https://doi.org/10.3390/ma4061034 CrossRefGoogle Scholar
  12. Nguyen C (2003) Rhizodeposition of organic C by plants : mechanisms and controls. Agronomie 23:375–396.  https://doi.org/10.1051/agro:2003011 CrossRefGoogle Scholar
  13. Ottow EA, Brinker M, Teichmann T, Fritz E, Kaiser W, Brosché M, Kangasjärvi J, Jiang X, Polle A (2005) Populus euphratica displays Apoplastic sodium accumulation, osmotic adjustment by decreases in calcium and soluble carbohydrates, and develops leaf succulence under salt stress. Plant Physiol 139:1762–1772.  https://doi.org/10.1104/pp.105.069971 CrossRefPubMedPubMedCentralGoogle Scholar
  14. Özmutlu C, Cengiz A (1990) Mass-attenuation coefficients of Beta particles. Appl Radiat Isot 41:545–549CrossRefGoogle Scholar
  15. Pausch J, Kuzyakov Y (2011) Photoassimilate allocation and dynamics of hotspots in roots visualized by 14C phosphor imaging. J Plant Nutr Soil Sci 174:12–19CrossRefGoogle Scholar
  16. Reichert WL, Stein JE, French B, Goodwin P, Varanasi U (1992) Storage phosphor imaging technique for detection and quantitation of DNA adducts measured by the 32P-postlabeling assay. Carcinogenesis 13:1475–1479CrossRefPubMedGoogle Scholar
  17. Richter WF, Starke V, Whitby B (2006) The distribution pattern of radioactivity across different tissues in quantitative whole-body autoradiography (QWBA) studies. Eur J Pharm Sci 28:155–165.  https://doi.org/10.1016/j.ejps.2006.01.007 CrossRefPubMedGoogle Scholar
  18. Solon EG, Lee F (2001) Methods determining phosphor imaging limits of quantitation in whole-body autoradiography rodent tissue distribution studies affect predictions of 14C human dosimetry. J Pharmacol Toxicol Methods 46:83–91.  https://doi.org/10.1016/S1056-8719(02)00162-4 CrossRefPubMedGoogle Scholar
  19. Story MD, Mendoza EA, Meyn RE, Tofilon PJ (1994) Pulsed-field gel electrophoretic analysis of DNA double-strand breaks in mammalian cells using photostimulable storage phosphor imaging. Int J Radiat Biol 65:523–528.  https://doi.org/10.1080/09553009414550611 CrossRefPubMedGoogle Scholar
  20. Thontadarya SR (1984) Effect of geometry on mass attenuation coefficient of β-particles. Int J Appl Radiat Isot 35:981–982.  https://doi.org/10.1016/0020-708X(84)90217-5 CrossRefGoogle Scholar
  21. Wichern F, Andreeva D, Joergensen RG, Kuzyakov Y (2011) Stem labeling results in different patterns of 14C rhizorespiration and 15N distribution in plants compared to natural assimilation pathways. J Plant Nutr Soil Sci 174:732–741.  https://doi.org/10.1002/jpln.201000206 CrossRefGoogle Scholar
  22. Yi CY, Han HS, Cho WK, Park UJ, Jun JS, Chai HS (1998) Calculation of mass attenuation coefficients of Beta particles. Radiat Prot Dosim 78:221–229.  https://doi.org/10.1093/oxfordjournals.rpd.a032355 CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Maire Holz
    • 1
    Email author
  • Mohsen Zarebanadkouki
    • 2
  • Andrea Carminati
    • 2
  • Yakov Kuzyakov
    • 3
    • 4
    • 5
  1. 1.Group of Isotope Biogeochemistry and Gas FluxesLeibniz Centre for Agricultural Landscape Research (ZALF) e.VMuenchebergGermany
  2. 2.Bayreuth Center of Ecology and Environmental Research (BayCEER)University of BayreuthBayreuthGermany
  3. 3.Institute of Physicochemical and Biological Problems in Soil ScienceRussian Academy of SciencesPushchinoRussia
  4. 4.Department of Soil Science of Temperate Ecosystems, Department of Agricultural Soil ScienceUniversity of GoettingenGoettingenGermany
  5. 5.Institute of Environmental SciencesKazan Federal UniversityKazanRussia

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