Input-Output Analysis of Phloem Partitioning Within Higher Plants

  • Peter E. H. Minchin


Phloem vasculature within higher plants functions at very high hydrostatic pressure (10 atmospheres). When the pressure is disrupted, there is a surge of flow that almost immediately results in blockage, making experimentation difficult. Therefore, there are few reliable measurements of sap contents and limited understanding of the biophysics of its flow. Consequently we still do not know how partitioning between competing sinks is controlled. In vivo measurement using radioactive tracers is an important tool in the study of phloem function, but has rarely been quantitatively analysed. A detailed time sequence of phloem sap movement through a plant is possible with in vivo measurement of 11C tracer, which is ideal for input-output analysis. Input-output analysis provides a parsimonious description of tracer movement. The only estimates of transport distribution times, pathway leakage, and partitioning between competing sinks that have been reported are based upon input-output analysis of 11C-labelled photosynthate. These quantitative measurements have led to the first mechanistic understanding of phloem partitioning between competing sinks, from which sink priority has been shown to be an emergent property.


Seminal Root Phloem Transport Pathway Leakage Label Leaf Tracer Pulse 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



I am indebted to Drs J.H. Troughton and W.F. Pickard who encouraged me right from the beginning to develop my understanding of input-output analysis, and to Professor P.C. Young for his encouragement and collaboration for over 30 years. Several of his students have had a big input into both data analysis and development of control systems used in the 11CO2 tracer facility. Dr M.R. Thorpe has been a long time collaborator and the sabbatical time of Prof J.F. Farrar spent in our laboratory introduced us to a lot of new plant applications.


  1. 1.
    Brouwer, R.: Distribution of dry matter in the plant. Neth. J. Agric. Sci. 10, 361–376 (1962) Google Scholar
  2. 2.
    Evans, N.T.S., Ebert, M., Moorby, J.: A model for the translocation of photosynthate in the soybean. J. Exp. Bot. 14, 221–231 (1963) CrossRefGoogle Scholar
  3. 3.
    Farrar, J.F., Minchin, P.E.H.: Carbon partitioning in split root systems of barley: relation to metabolism. J. Exp. Bot. 42, 1261–1269 (1991) CrossRefGoogle Scholar
  4. 4.
    Farrar, J.F., Minchin, P.E.H., Thorpe, M.R.: Carbon import into barley roots: stimulation by galactose. J. Exp. Bot. 45, 17–22 (1994) CrossRefGoogle Scholar
  5. 5.
    Farrar, J.F., Minchin, P.E.H., Thorpe, M.R.: Carbon import into barley roots: effects of sugars and relation to cell expansion. J. Exp. Bot. 46, 1859–1865 (1995) CrossRefGoogle Scholar
  6. 6.
    Fondy, B.R., Geiger, D.R.: Effect of rapid changes in sink-source ratio on export and distribution of products of photosynthesis in leaves of Beta vulgaris L. and Phaseolus vulgaris L. Plant Physiol. 66, 945–949 (1980) CrossRefGoogle Scholar
  7. 7.
    Gifford, R.M., Evans, L.T.: Photosynthesis, carbon partitioning, and yield. Annu. Rev. Plant Physiol. 32, 485–509 (1981) CrossRefGoogle Scholar
  8. 8.
    Gould, N., Minchin, P.E.H., Thorpe, M.R.: Direct measurements of sieve element hydrostatic pressure reveal strong regulation after pathway blockage. Funct. Plant Biol. 31, 987–993 (2004) CrossRefGoogle Scholar
  9. 9.
    Grossman, L., DeJong, T.M.: Peach: A simulation model of reproductive and vegetative growth in peach trees. Tree Physiol. 14, 329–345 (1994) Google Scholar
  10. 10.
    Heuvelink, E.: Re-interpretation of an experiment on the role of assimilate transport resistance in partitioning in tomato. Ann. Bot. 78, 467–470 (1996) CrossRefGoogle Scholar
  11. 11.
    Jahnke, S., Stocklin, G., Willenbrink, J.: Translocation profiles of 11C-assimilates in the petiole of Marsilea quadrifolia L. Planta 153, 56–63 (1981) CrossRefGoogle Scholar
  12. 12.
    Jahnke, S., Menzel, M.I., van Dusschoten, D., Roeb, G.W., Buhler, J., Minwuyelet, S., Blumler, P., Temperton, V.M., Hombach, T., Streun, M., Beer, C., Khodaverdi, M., Ziemons, K., Coenen, H.H., Schurr, U.: Combined MRI-PET dissects dynamic changes in plant structures and functions. Plant J. 59, 634–644 (2009) CrossRefGoogle Scholar
  13. 13.
    Kays, S.J., Goeschl, J.D., Magnuson, C.E., Fares, Y.: Diurnal changes in fixation, transport, and allocation of carbon in the sweet potato using 11C tracer. J. Am. Soc. Horticult. Sci. 112, 545–554 (1987) Google Scholar
  14. 14.
    Kendall, M.G., Stuart, A.: The Advanced Theory of Statistics, vol. II. Griffen, London (1961) Google Scholar
  15. 15.
    Lacointe, A., Minchin, P.E.H.: Modelling phloem and xylem transport within a complex architecture. Funct. Plant Biol. 35, 772–780 (2008) CrossRefGoogle Scholar
  16. 16.
    Minchin, P.E.H., Troughton, J.H.: Quantitative interpretation of phloem translocation data. Annu. Rev. Plant Physiol. 31, 191–215 (1980) CrossRefGoogle Scholar
  17. 17.
    Minchin, P.E.H., Thorpe, M.R.: Apoplastic phloem unloading in the stem of bean. J. Exp. Bot. 35, 538–550 (1984) CrossRefGoogle Scholar
  18. 18.
    Minchin, P.E.H., Ryan, K.G., Thorpe, M.R.: Further evidence of apoplastic unloading into the stem of bean. Identification of the phloem buffering pool. J. Exp. Bot. 35, 1744–1753 (1984) CrossRefGoogle Scholar
  19. 19.
    Minchin, P.E.H., Thorpe, M.R.: Measurement of unloading and reloading of photo-assimilate within the stem of bean. J. Exp. Bot. 38, 211–220 (1987) CrossRefGoogle Scholar
  20. 20.
    Minchin, P.E.H., Grusak, M.A.: Continuous in vivo measurement of carbon partitioning within whole plants. J. Exp. Bot. 39, 561–571 (1988) CrossRefGoogle Scholar
  21. 21.
    Minchin, P.E.H.: System estimation in plant physiology. In: Young, P.C. (ed.) Concise Encyclopedia of Environmental Systems, pp. 570–579. Pergamon Press, Oxford (1993) Google Scholar
  22. 22.
    Minchin, P.E.H., Thorpe, M.R., Farrar, J.F.: A simple mechanistic model of phloem transport which explains sink priority. J. Exp. Bot. 44, 947–955 (1993) CrossRefGoogle Scholar
  23. 23.
    Minchin, P.E.H., Farrar, J.F., Thorpe, M.R.: Partitioning of carbon in split root systems of barley: effect of temperature of the root. J. Exp. Bot. 45, 1103–1109 (1994) CrossRefGoogle Scholar
  24. 24.
    Minchin, P.E.H., Thorpe, M.R., Farrar, J.F.: Short-term control of root:shoot partitioning. J. Exp. Bot. 45, 615–622 (1994) CrossRefGoogle Scholar
  25. 25.
    Minchin, P.E.H., Lees, M.J., Thorpe, M.R., Young, P.C.: What can tracer profiles tell us about the mechanisms giving rise to them? J. Exp. Bot. 47, 275–284 (1996) CrossRefGoogle Scholar
  26. 26.
    Minchin, P.E.H., Thorpe, M.R., Wunsche, J., Palmer, J.W., Picton, R.F.: Carbon partitioning between apple fruits: short- and long-term responses to available photosynthate. J. Exp. Bot. 48, 1401–1406 (1997) CrossRefGoogle Scholar
  27. 27.
    More, R.D.: Production of short-lived isotopes. In: Minchin, P.E.H. (ed.) Short-Lived Isotope in Biology. Proceedings of an International Workshop on Biological Research with Short-Lived Isotopes, Wellington. DSIR Bulletin, vol. 238 (1985). (Available from P.E.H. Minchin) Google Scholar
  28. 28.
    More, R.H., Troughton, J.H.: Production of 11C with a 3-MeV Van de Graaff accelerator. Int. J. Appl. Radiat. Isot. 23, 344–345 (1972) CrossRefGoogle Scholar
  29. 29.
    Shinpei, M., Shu, F., Hiroshi, U., Noriko, I.S., Tamikazu, K.: A new visualization technique for the study of the accumulation of photoassimilates in wheat grains using [11C]CO2. Appl. Radiat. Isot. 64, 435–440 (2006) CrossRefGoogle Scholar
  30. 30.
    Thorpe, M.R., Minchin, P.E.H.: Continuous monitoring of fluxes of photoassimilate in leaves and whole plants. J. Exp. Bot. 42, 461–468 (1991) CrossRefGoogle Scholar
  31. 31.
    Thorpe, M.R., MacRae, E.A., Minchin, P.E.H., Edwards, C.M.: Galactose stimulation of carbon import into roots is confined to the Poaceae. J. Exp. Bot. 50, 1613–1618 (1999) CrossRefGoogle Scholar
  32. 32.
    Thornley, J.H.M.: Modelling allocation with transport/conversion processes. Silva Fenn. 31, 341–355 (1997) Google Scholar
  33. 33.
    van Bel, A.J.E.: The phloem, a miracle of ingenuity. Plant Cell Environ. 26, 125–149 (2003) CrossRefGoogle Scholar
  34. 34.
    Wardlaw, I.F.: The control of carbon partitioning. New Phytol. 116, 341–381 (1990) CrossRefGoogle Scholar
  35. 35.
    Wright, C.J.: Interactions between vegetative and reproductive growth. In: Wright, C.J. (ed.) Manipulation of Fruiting. Butterworths, London (1989) Google Scholar
  36. 36.
    Young, P.: Recursive approaches to time series analysis. Bull. Inst. Math. Appl. 10, 209–224 (1974) Google Scholar
  37. 37.
    Young, P.: Recursive Estimation and Time-Series Analysis. An Introduction. Springer, Berlin (1984) MATHGoogle Scholar
  38. 38.
    Young, P.C., Minchin, P.E.H.: Environmental time-series analysis: modelling natural systems from experimental time-series data. Int. J. Biol. Macromol. 13, 190–201 (1991) CrossRefGoogle Scholar

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© Springer-Verlag London Limited 2012

Authors and Affiliations

  • Peter E. H. Minchin
    • 1
  1. 1.The New Zealand Institute for Plant and Food Research LimitedTe PukeNew Zealand

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