Investigation of Mechanisms of Potassium and Cesium-137 Uptake by Plants with Optical and Gamma Spectrometries in the Field under Water-Stressed Conditions
Channels of the 137Cs and potassium transfer from soil to plants in the field under water-stressed conditions are investigated. Different rapidly maturing plants were grown and selected simultaneously several times during the 2012 and 2013 seasons at the same experimental sites with different soil types under natural conditions at the Chornobyl 10-km Exclusion Zone. After each selection, the contents of 137Cs and K in the plants and extracted soil solutions were measured. Potassium and cesium entered plant roots, as a rule, through transporters with low selectivity, when the concentration of dissolved potassium (CK) in soil was greater than 2 /ug/cm3. In this case, the selectivity of the plant uptake for 137Cs versus potassium r was near 1. However, when CK was between 0.5 and 2 /ug/cm3, potassium also appeared to enter plant roots through highly selective potassium transporters, while cesium entered roots only through the transporters with low selectivity. In this case, the value of r was much less than 1. When CK was less than 0.5 /ug/cm3, cesium and potassium appeared to enter roots through a complement of transporters with greater selectivity for cesium than for potassium. The value of r in this case could exceed 1.
- P.J. White, M.R. Broadley. Mechanisms of caesium uptake by plants. New Phytol. 147, 241 (2000).
- Y.-G. Zhu, E. Smolders. Plant uptake of radiocaesium: A review of mechanisms, regulation and application. J. Exp. Bot. 51, 1635 (2000).
- P.J. White, L. Wiesel, M.R. Broadley. Cation channels and the uptake of radiocaesium by plants. In: Ion Channels and Plant Stress Responses, edited by V. Demidchik, F. Maathuis (Springer, 2010).
- M.R. Broadley, A.J. Escobar-Guti’errez, H.C. Bowen, N.J. Willey, P.J. White. Influx and accumulation of Cs+ by the akt1 mutant of Arabidopsis thaliana (L.) Heynh. lacking a dominant K+ transport system. J. Exp. Bot. 52, 839 (2001).
- C.R. Hampton, M.R. Broadley, P.J. White. Short review: The mechanisms of radiocaesium uptake by Arabidopsis roots. Nukleonika 50, S3 (2005).
- Z. Qi, C.R. Hampton, R. Shin, B.J. Barkla, P.J. White, D.P. Schachtman. The high affinity K+ transporter AtHAK5 plays a physiological role in planta at very low K+ concentrations and provides a caesium uptake pathway in Arabidopsis. J. Exp. Bot. 59, 595 (2008).
- J.J. Ayub, R.L. Valverde, M.J. Garc’?a-Sanchez, J.A. Fernandez, R.H. Velasco. Kinetics of Caesium and Potassium Absorption by Roots of Three Grass Pastures and Competitive Effects of Potassium on Caesium Uptake in Cynodon sp.World History of Radon Research and Measurement from the Early 1900's to Today, edited by A.S. Paschoa (American Institute of Physics, 2008), p. 269.
- V. Demidchik, R.J. Davenport M. Tester. Nonselective cation channels in plants. Annu. Rev. Plant Biol. 53, 67 (2002).
- P.J. White, A.J. Karley. Potassium. In Cell Biology of Metals and Nutrients, edited by R. Hell, R.-R. Mendel (Springer, 2010), p. 199.
- P.J. White. Improving potassium acquisition and utilisation by crop plants. J. Plant Nutr. Soil Sci. 176, 305 (2013).
- F.J.M. Maathuis, D. Sanders. Mechanisms of potassium absorption by higher plant roots. Physiol. Plant. 96, 158 (1996).
- F.J.M. Maathuis, A.M. Ichida, D. Sanders, J.I. Shroeder. Roles of High Plant K+ Channels. Plant Physiol. 114, 1141 (1997).
- C.R. Hampton, M.R. Droadlug, P.J. White. Short review: The mechanisms of radiocaesium uptake by Arabidopsis roots. Nukleonika 50, S3 (2005).
- S. Fujimura, J. Ishikawa, Y. Sakuma, T. Saito, M. Sato, K. Yoshioka. Theoretical model of the effect of potassium on the uptake of radiocesium by rice. J. Environ. Radioact. 138, 122 (2014).
- V.V. Prorok, C.F.V. Mason, L.A. Bulavin, L.V. Poperenko. The factors determining channels of Cs-137 and K transfer from soil to plant under natural conditions. In: International Conference Twenty-five Years after Chernobyl Accident. Safety for the Future. April 20-22, 2011, Kyiv, Ukraine. Reports proc. Conclusions and recommendations (Kyiv, 2011).
- V.V. Prorok, L.A. Bulavin, L.V. Poperenko. Investigation of channels of Cs-137 and K transfer from soil to plant under natural conditions with optical and gamma spectrometry. Ukr. J. Phys. 57, 230 (2012).
- V.V. Prorok, A.P. Ganushevich, T.I. Makarenko, V.V. Ostashko, L.V. Poperenko, L.Yu. Melnichenko. Strontium and calcium relations in plant and soil solution on Chornobyl affected areas. Ukr. J. Phys. 59, 233 (2014).
- V.V. Prorok, P.J. White, O.I. Dacenko, L.A. Bulavin, S.E. Zelensky, L.Yu. Melnychenko, S.G. Rozouvan, L.V. Poperenko. Dependence of the concentrations of cesium-137 and potassium in extracted soil solutions on soil humidity before centrifugation. Nuclear Phys. Atom. Energy 18, 87 (2017).
- V.V. Prorok, O.I. Dacenko, L.A. Bulavin, L.V. Poperenko, P.J. White. Mechanistic interpretation of the varying selectivity of Cesium-137 and potassium uptake by radish (Raphanus sativus L.) under field conditions near Chernobyl. J. Environ. Radioact. 152, 85 (2016).