This work presents an original methodological and technical approach based on low-field spin-echo NMR for non-invasive and continuous study of water transfer in the roots of intact plants under impact of elevated concentration of carbon dioxide (CO2). To realize this approach, portable plant growth chamber, that can be paired with an NMR system and a gas system, was made. The study of the intensity of intercellular water transfer was carried out on the basis of measuring of water self-diffusion coefficient in the root tissues. For this, the spin-echo NMR method with a pulsed magnetic field gradient was used. Using the method presented in the present work, it was shown that water permeability of cells in radial direction of root suction zone decreases by about 1.5 times with CO2 enrichment to a maximum value of 1%/ For the first time, the dynamics of changes in water conductivity in the roots depending on the concentration of CO2 was obtained. It was shown that the magnitude and the rate of decreasing of water conductivity is increase with CO2 concentration enrichment. It is supposed, that transmembrane pathway of water transfer through aquaporins makes a significant contribution to the total decrease in the intercellular water conductivity in root tissues under elevated CO2 concentration.
carbon dioxide, water transport in plant roots, nuclear magnetic resonance
1. Qiao Y., Zhang H., Dong B., Shi Ch., Li Y., Zhai H., Liu M. Effects of elevated CO2 concentration on growth and water use efficiency of winter wheat under two soil water regimes. Agricultural Water Management, 2010, vol. 97, pp. 1742-1748.
2. Prior S.A., Runion G.B., Marble S.Ch., Rogers H.H., Gilliam Ch.H., Torbert H.A. A review of elevated atmospheric co2 effects on plant growth and water relations: implications for horticulture. Hort Science, 2011, vol. 46, no. 2, pp. 158-162.
3. Jiang Y., Xu Z., Zhou G., Liu T. Elevated CO2 can modify the response to a water status gradient in a steppe grass: from cell organelles to photosynthetic capacity to plant growth. BMC Plant Biology, 2016, vol. 16. DOI:https://doi.org/10.1186/s12870-016-0846-9.
4. Zaghdoud Ch., Mota-Cadenas C., Carvajal M., Muries B., Ferchichi A., Martínez-Ballesta M. Elevated CO2 alleviates negative effects of salinity on broccoli (Brassica oleracea L. var Italica) plants by modulating water balance through aquaporins abundance. Environmental and Experimental Botany, 2013, vol. 95, pp.15-24.
5. Huang B., Xu Y. Cellular and molecular mechanisms for elevated CO2 regulation of plant growth and stress adaptation. Crop Science, 2015, vol. 55, pp. 1-20.
6. Domec J.-C., Palmroth S., Ward E., Maier Ch., Therezien M., Oren R. Acclimation of leaf hydraulic conductance and stomatal conductance of Pinus taeda (loblolly pine) to long-term growth in elevated CO2 (free-air CO2 enrichment) and N-fertilization. Plant, Cell and Environment, 2009. DOI:https://doi.org/10.1111/j.1365-3040.2009.02014.x.
7. Hao Guang-You, Holbrook N.M., Zwieniecki M.A., Gutschick V.P., Bassiri-Rad H. Coordinated responses of plant hydraulic architecture with the reduction of stomatal conductance under elevated CO2 concentration. Tree Physiology OO, 2018, pp. 1-12.
8. Sarker B.C., Hara M. Effects of elevated CO2 and water stress on root structure and hydraulic conductance of solanum melongena l. Bangladesh J. Bot., 2009, vol. 38, no. 1, pp. 55-63.
9. Leakey A.D.B., Ainsworth E.A., Bernacchi C.J., Rogers A., Long S.P., Ort D.R. Elevated CO2 effects on plant carbon, nitrogen and water relations: six important lessons from FACE. Journal of Experimental Botany, 2009, vol. 60, pp. 2859-2876.
10. Calvo O.C., Franzaring J., Schmid I., Fangmeier A. Root exudation of carbohydrates and cations from barley in response to drought and elevated CO2. Plant and Soil, 2019, vol. 438, pp. 127-142.
11. Easlon H.M., Bloom A.J. The effects of rising atmospheric carbon dioxide on shoot-root nitrogen and water signaling. Frontiers in Plant Science, 2013, vol. 4. DOI:https://doi.org/10.3389/fpls.2013.00304.
12. Gorska A., Ye Q., Holbrook N.M., Zwieniecki M.A. Nitrate control of root hydraulic properties in plants: translating local information to whole plant response. Plant Physiology, 2008, pp. 1159-1167.
13. Gebauer T., Bassiri-Rad H. Effects of high atmospheric CO2 concentration on root hydraulic conductivity of conifers depend on species identity and inorganic nitrogen source. Environmental Pollution, 2011, vol. 159, pp. 3455-3461.
14. Stirzaker R.J., Passioura J.B. The water relations of the root-soil interface. Plant, Cell and Environment, 1996, vol. 19, pp. 201-208.
15. Velikanov G.A., Sibgatullin T.A., Belova L.P., Ionenko I.F. Membrane water permeability of maize root cells under two levels of oxidative stress. Protoplasma, 2015, vol. 252, pp. 1263-1273.
16. Anisimov A.V., Dautova N.R., Suslov M.A. Growth function and intercellular water transfer in excised roots. Protoplasma, 2019. DOI:https://doi.org/10.1007/s00709-019-01388-w.
17. Cho C.H., Hong Y.S., Kang K., Volkov V.I., Skirda V., Lee C.Y., Lee C.H. Water self-diffusion in Chlorella sp. studied by pulse field gradient NMR. Magn Reson Imaging, 2003, vol. 21, pp. 1009-1017.
18. Van As.H. Intact plant MRI for the study of cell water relations, membrane permeability, cell-to-cell and long distance water transport. Journal of Experimental Botany, 2007, vol. 58, pp. 743-756.
19. Ishida N., Koizumi M., Kano H. The NMR microscope: a unique and promising tool for plant science. Annual Botany, 2000, vol. 86, pp. 259-278.
20. Anisimov A.V. Spin-echo NMR study of the translational water diffusion selectively along the apoplast and the cytoplasmic and vacuolar symplasts of plants. Biophysics, 2004, vol. 49, pp. 816-821.
21. Tanner J.E. Use of the stimulated echo in NMR diffusion studies. Journal of Chemical Physics, 1970, vol. 52, pp. 2523-2526.
22. Anisimov A.V., Sorokina N.Y., Dautova N.R. Water diffusion in biological porous systems: a NMR approach. Magn Reson Imaging, 1998, vol. 16, pp. 565-568.
23. Crick F. Diffusion in embryogenesis. Nature, 1970, vol. 225, pp. 420-422.
24. Cooper R.L., Chang D.B., Young A.C., Martin C.J., Ancker-Johnson B. Restricted diffusion in biophysical systems. Biophysical Journal, 1974, vol. 14, pp. 161-177.
25. Javot H., Maurel C. The role of aquaporins in root water uptake. Annual Botany, 2002, vol. 90, pp. 301-313.
26. Adiredjo A., Navaud O., Grieu Ph., Lamaze Th. Hydraulic conductivity and contribution of aquaporins to water uptake in roots of four sunflower genotypes. Botanical Studies, 2014, vol. 55. DOI:https://doi.org/10.1186/s40529-014-0075-1.
27. Sutka M., Li G., Boudet J., Boursiac Y., Doumas P., Maurel C. Natural variationof root hydraulics in Arabidopsis grown in normal and salt-stressed conditions. Plant Physiology, 2011, vol. 155, pp. 1264-1276.
28. Anisimov A.V., Suslov M.A., Alyab’ev A.Yu. Symplasmic transport of water along the root depends on pressure. Russ. J. Plant. Physiol., 2014, vol. 61. DOI:https://doi.org/10.1134/S1021443714040025.
29. Carr D.H., Brown J., Bydder G.M., Steiner R.E., Weinmann H.J., Speck U., Hall A.S., Young I.R. Gadolinium-DTPA as a contrast agent in MRI: Initial clinical experience in 20 patients. Am. J. Radiol., 1984, vol. 143, no. 2, pp. 215-224.
