Abstract
A flow-sensitive nuclear magnetic resonance (NMR) microimaging technique was applied to measure directly the in-vivo water flow in 6-d-old castor bean seedlings. The achieved in-plane resolution of the technique allowed discrimination between xylem and phloem water flow. Both the xylem- and the phloem-average flow velocities in the intact seedling could be quantified. Furthermore, the total conductive cross-sectional area of the xylem vessels and the phloem sieve elements could be determined using the non-invasive and non-destructive NMR microimaging technique. Hence, it was possible to calculate the in-vivo volume flow rates for both xylem and phloem water flow. Our non-destructive technique showed that previously used methods to measure phloem water flow affected the flow rate itself. In the intact seedlings we found values of 16.6 μl·h−1, two fold lower than those previously estimated from phloem exudation rates. Finally, our results demonstrate for the first time that water is internally circulated between phloem and xylem, and that water flow within the xylem is maintained by this internally circulated water, even in the absence of any significant transpiration or evaporation.
Similar content being viewed by others
Abbreviations
- NMR:
-
nuclear magnetic resonance
References
Boyer JS (1974) Water transport in plants. Planta 117: 187–207
Callaghan PT (1991) Principles of nuclear magnetic resonance microscopy. Clarendon Press, Oxford
Callaghan PT, Xia Y (1991) Velocity and diffusion imaging in dynamic NMR microscopy. J Magn Reson 91: 326–352
Callaghan PT, Jeffrey KR, Xia Y (1992) Translational motion imaging with pulsed gradient spin echo methods. In: Blumich B, Kuhn W (eds) Magnetic resonance microscopy: methods and applications to materials science, plants and biomedicine. Verlag Chemie, Weinheim, pp 327–347
Callaghan PT, Köckenberger W, Pope JM (1994) The use of difference propagators for imaging of capillary flow in the presence of stationary fluid. J Magn Reson B 104: 183–188
Currier HB, Strugger S (1956) Aniline blue and fluorescence microscopy of callose in bulb scales ofAllium cepa L. Protoplasma 45: 552–559
French J, Steudle E (1989) Axial and radial hydraulic resistance to roots of maize (Zea mays L.). Plant Physiol 91: 719–726
Grignon N, Touraine B, Durand M (1989) 6(5) Carboxyfluorescein as a tracer of phloem sap translocation. Am J Bot 76: 871–877
Hall SM, Baker DA, Milburn JA (1971) Phloem transport of14C-labelled assimilates inRicinus. Planta 100: 200–207
Hollinger DY, Kelliher FM, Schulze E-D, Koestner BMM (1994) Coupling of tree transpiration to atmospheric turbulence. Nature 371: 60–62
Kallarackal J, Orlich G, Schobert C, Komor E (1989) Sucrose transport into the phloem ofRicinus communis L. seedlings as measured by the analysis of sieve-tube sap. Planta 177: 327–335
Kriedemann P, Beevers H (1967) Sugar uptake and translocation in the castor bean seedling. 1. Characteristics of transfer in intact and excised seedlings. Plant Physiol 42: 161–173
Lockhart JA (1965) An analysis of irreversible plant cell elongation. J Theor Biol 8: 264–276
Metzler A, Köckenberger W, von Kienlin M, Komor E, Haase A (1994) Quantitative measurement of sucrose distribution inRicinus communis seedlings by chemical shift microscopy. J Magn Reson B 105: 249–252
Minchin PE, Troughton JH (1980) Quantitative interpretation of phloem translocation data. Annu Rev Plant Physiol 31: 191–215
Mortimer DC (1964) Translocation of the products of photosynthesis in sugar beet petioles. Can J Bot 43: 269–280
Münch E (1930) Stoffbewegungen in der Pflanze. Gustav Fischer Verlag, Jena
Munns R, Passioura JB (1984) Effect of prolonged exposure to sodium chloride on the osmotic pressure of leaf xylem sap from intact transpiring barley plants. Aust J Plant Physiol 11: 497–508
Oparka KJ (1991) Uptake and compartmentation of fluorescent probes by plant cells. J Exp Bot 42: 565–579
Oparka KJ, Duckett CM, Prior DAM, Fisher DB (1994) Real-time imaging of phloem unloading in the root tip ofArabidopsis. Plant J 6: 759–766
Orlich G, Komor E (1992) Phloem loading inRicinus cotyledons: sucrose pathways via the mesophyll and the apoplasm. Planta 187: 460–474
Rumpel H, Pope JM (1992) The application of 3D chemical shift microscopy to non-invasive histochemistry. Magn Reson Imaging 10: 187–194
Schobert C, Komor E (1990) Transfer of amino acids and nitrate from the roots into the xylem ofRicinus communis seedlings. Planta 181: 85–90
Schulz A (1994) Phloem transport and differential unloading in pea seedlings after source and sink manipulations. Planta 192: 239–248
Smith JAC (1991) Ion transport and the transpiration stream. Bot Acta 104: 416–421
Stejskal EO (1965) The use of spin echoes in a pulsed magnetic field to study anisotropic restricted diffusion and flow. J Chem Phys 43: 3597–3603
Steudle E, Jeschke WD (1983) Water transport in barley roots. Planta 158: 237–248
Tammes PML, van Die J (1964) Studies of phloem exudation fromYucca flaccida. Acta Bot Neer 13: 76–83
Tanner W, Beevers H (1990) Does transpiration have an essential function in long-distance ion transport in plants? Plant Cell Environ 13: 745–750
Tanner W, Beevers H (1991) Comments on the article of J.A.C. Smith “Ion transport and the transpiration stream”. Bot Acta 104: 422
White PR, Schuker E, Kern JR, Fuller FH (1958) Root-pressure in gymnosperms. Science 128: 308–309
Wolswinkel P, Ammerlan A (1984) Turgor-sensitive sucrose and amino acid transport into developing seeds ofPisum sativum. Effect of high sucrose or mannitol concentration in experiments with empty ovules. Physiol Plant 61: 172–182
Xia Y, Jelinski LW (1995) Imaging low concentration metabolites in the presence of a large background signal. J Magn Reson B 107: 1–9
Zhong W, Langenberger S, Komor E, Schobert C (1995) Phosphatemediated increase of the sieve-tube conductance inRicinus communis L. seedlings is accompanied by a marked acidification of the sieve-tube sap. J Plant Physiol 145: 453–458
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Köckenberger, W., Pope, J.M., Xia, Y. et al. A non-invasive measurement of phloem and xylem water flow in castor bean seedlings by nuclear magnetic resonance microimaging. Planta 201, 53–63 (1997). https://doi.org/10.1007/BF01258680
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01258680