Planta

, Volume 77, Issue 3, pp 261–276 | Cite as

Effect of assimilate utilization on photosynthetic rate in wheat

  • R. W. King
  • I. F. Wardlaw
  • L. T. Evans
Article

Summary

Two weeks after anthesis, when the grain is filling rapidly, the rate of photosynthesis by flag leaves of wheat cv. Gabo was between 20 and 30 mg CO2 dm-2 leaf surface hour-1 under the conditions used. About 45% of flag-leaf assimilates were translocated to the ear, and only about 12% to the roots and young shoots.

On removing the ear, net photosynthesis by the flag leaves was reduced by about 50% within 3–15 hours, and there was a marked reduction in the outflow of 14C-labelled assimilates from the flag leaves.

Subsequent darkening of all other leaves on plants without ears led to recovery of flag-leaf photosynthesis, as measured by gas analysis and 14CO2 fixation, and to increased translocation of assimilates to the roots and young shoots. Minor changes in the rates of dark respiration accompanied these major, reversible changes in photosynthetic rate.

After more than a week in continuous, high-intensity light, the rate of photosynthesis by flag leaves of intact plants had fallen considerably, but could be restored again by a period in darkness, or by inhibiting photosynthesis in the ears by spraying them with DCMU. The inhibition of ear photosynthesis increased translocation of labelled assimilates from the flag leaf to the ears, without affecting leaf sugar levels.

The application of TIBA to the culm below the ear inhibited auxin movement throught the culm, but had no influence on flag-leaf photosynthesis.

These results suggest that, at least in this system, photosynthesis by the flag leaf is regulated directly by the demand for assimilates from the flag leaf and not indirectly through action in the leaf of auxins produced by the “sink” organs.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Alvim, P. de T.: Net assimilation rate and growth behaviour of beans as affected by gibberellic acid, urea, and sugar sprays. Plant Physiol. 35, 285–288 (1960).Google Scholar
  2. Andersson, G.: Gas exchange and frost hardening studies in winter cereals. Gleerupska. Lund: Univ. bokhand. 1944.Google Scholar
  3. Asana, R. D., and C. M. Joseph: Studies in physiological analysis of yield. VII. Effect of temperature and light on the development of the grain of two wheat varieties. Indian J. Plant Physiol. 7, 86–101 (1964).Google Scholar
  4. Bakhuyzen, H. L. Van der Sande: Bloei en bloeihormonen in het bijzonder bij tarwe. I. Minist. Landb. Verslag Onderz. 53, 145–212 (1947).Google Scholar
  5. Bidwell, R. G. S., and W. B. Turner: Effect of growth regulators on CO2 assimilation in leaves, and its correlation with the bud break response in photosynthesis. Plant Physiol. 41, 267–270 (1966).Google Scholar
  6. Bierhuizen, J. F., R. O. Slatyer, and C. W. Rose: A porometer for laboratory and field operation. J. Exp. Bot. 16, 182–191 (1965).Google Scholar
  7. Bingham, J.: Paternal effect of grain size in wheat. Nature (Lond.) 209, 940–941 (1966).Google Scholar
  8. Birecka, H., and L. Dakić-Wlodkowska: Photosynthesis, translocation and accumulation of assimilates in cereals during grain development. III. Spring wheat — photosynthesis and the daily accumulation of photosynthates in the grain. Acta Soc. Bot. Pol. 32, 631–650 (1963).Google Scholar
  9. Booth, A., J. Moorby, C. R. Davies, H. Jones, and P. F. Wareing: Effects of indolyl-3-acetic acid on the movement of nutrients within plants. Nature (Lond.) 204, 204–205 (1962).Google Scholar
  10. Burt, R. L.: Carbohydrate utilization as a factor in plant growth. Aust. J. biol. Sci. 17, 867–877 (1964).Google Scholar
  11. Crafts, A. S.: The chemistry and mode of action of herbicides. New York: Interscience Publ. 1961.Google Scholar
  12. Davies, C. R., and P. F. Wareing: Auxin-directed transport of radiophosphorus in stems. Planta (Berl.) 65, 139–156 (1965).Google Scholar
  13. Egamberdyev, A. E., K. A. Aliev, and Yu S. Nasyrov: On the movement of the products of photosynthesis (C14) from the leaves to the bolls in cotton. Temat. Sbor. Otd. Fiziol. Lit. Biofiz. Rast. Akad. Nauk Tadsh. S.S.R. 4, 36–41 (1963).Google Scholar
  14. Evans, L. T., and I. F. Wardlaw: Inflorescence initiation in Lolium temulentum L. IV. Translocation of the floral stimulus in relation to that of assimilates. Aust. J. biol. Sci. 17, 1–9 (1964).Google Scholar
  15. Ewart, A. J.: On assimilatory inhibition in plants. J. Linnean Soc. Bot. 31, 364–461 (1896).Google Scholar
  16. Hartt, C.: Translocation as a factor in photosynthesis. Naturwissenschaften 50, 666–667 (1963).Google Scholar
  17. Hew, C. S., C. D. Nelson, and G. Krotkov: Hormonal control of the translocation of photosynthetically assimilated 14C in young soybean plants. Amer. J. Bot. 54, 252–256 (1967).Google Scholar
  18. Humphries, E. C.: Dependence of net assimilation rate on root growth of isolated leaves. Ann. Bot., NS. 27, 175–183 (1963).Google Scholar
  19. Humphries, E. C., and G. N. Thorne: The effect of root formation on photosynthesis of detached leaves. Ann. Bot., NS. 28, 391–400 (1964).Google Scholar
  20. Jenkins, H. V.: An airflow planimeter for measuring the area of detached leaves. Plant Physiol. 34, 532–536 (1959).Google Scholar
  21. Kende, H.: Kinetin-like factors in the root exudate of sunflowers. Proc. nat. Acad. Sci. (Wash.) 53, 1302–1307 (1965).Google Scholar
  22. Kiesselbach, T. A.: Endosperm type as a physiological factor in corn yields. J. Amer. Soc. Agron. 40, 216–236 (1948).Google Scholar
  23. Kulaeva, O. N.: Effects of roots on the metabolism of leaves in connection with the action of kinetin on leaves. Fiziol. Rast. 9, 229–239 (1962).Google Scholar
  24. Kurssanow, A. L.: Die Photosynthese grüner Früchte und ihre Abhängigkeit von der normalen Tätigkeit der Blätter. Planta (Berl.) 22, 240–250 (1934).Google Scholar
  25. Maggs, D. H.: Growth rates in relation to assimilate supply and demand. I. Leaves and roots as limiting regions. J. Exp. Bot. 15, 574–583 (1964).Google Scholar
  26. Moss, D. N.: Photosynthesis and barrenness. Crop. Sci. 2, 366 (1962).Google Scholar
  27. Nösberger, J., and E. C. Humphries: Influence of removing tubers on dry matter production and net assimilation rate of potato plants. Ann. Bot., N.S. 29, 580–588 (1965).Google Scholar
  28. O'Brien., T. P., and I. F. Wardlaw: The direct assay of 14C in dried plant materials. Aust. J. biol. Sci. 14, 361–367 (1961).Google Scholar
  29. Pescod, D., W. R. Read, and D. W. Cunliffe: Engineering aspects of environment control for plant growth, p. 175–183. Melbourne: CSIRO 1962.Google Scholar
  30. Ponigrahi, B. M., and L. J. Audus: Apical dominance in Vicia faba. Ann. Bot., N.S. 30, 457–473 (1966).Google Scholar
  31. Povolotskaya, K. L., Y. V. Rakitin, and I. V. Khovanskaya: Role of heteroauxin in sugar translocation. Fiziol. Rast. 9, 303–308 (1962).Google Scholar
  32. Quinlan, J. D., and G. R. Sagar: An autoradiographic study of the movement of 14C-labelled assimilates in the developing wheat plant. Weed Res. 2, 264–273 (1962).Google Scholar
  33. Richmond, A. E., and A. Lang: Effect of kinetin on protein content and survival of detached Xanthium leaves. Science 125, 650–651 (1957).Google Scholar
  34. Sebanek, J.: The effect of amputation of cotyledon and application of growth regulators on the transport of 32P in decapitated pea seedlings. Biol. Plant. 7, 380–386 (1965).Google Scholar
  35. Seth, A. K., and P. F. Wareing: Hormone-directed transport of metabolites and its possible role in plant senescence. J. Exp. Bot. 18, 65–77 (1967).Google Scholar
  36. Sircar, S. M., and M. Chakravorty: Studies on the physiology of rice. XIII. Distribution of free auxin in different organs of the plant. Proc. nat. Inst. Sci. India 23, 102–116 (1957).Google Scholar
  37. Stoy, V.: Photosynthesis, respiration, and carbohydrate accumulation in spring wheat in relation to its yield. Physiol. Plant. (København), Suppl. 4, 1–125 (1965).Google Scholar
  38. Sweet, G. B., and P. F. Wareing: Role of plant growth in regulating photosynthesis. Nature (Lond.) 210, 77–79 (1966).Google Scholar
  39. Thorne, G. N.: Physiological aspects of grain yield in cereals. In: The growth of cereals and grasses (F. L. Milthorpe and J. D. Ivins, eds.), p. 88–105. London: Butterworths & Co. 1966.Google Scholar
  40. —, and A. F. Evans: Influence of tops and roots on net assimilation rate of sugarbeet and spinach-beet and grafts between them. Ann. Bot., N.S. 28, 499–508 (1964).Google Scholar
  41. Tognoni, F., A. H. Halevy, and S. M. Wittwer: Growth of bean and tomato plants as affected by root absorbed growth substances and atmospheric carbon dioxide. Planta (Berl.) 72, 43–52 (1967).Google Scholar
  42. Tsuno, Y., and K. Fujise: Studies on the dry matter production of the sweet potato. Proc. Crop Sci. Soc. Japan 33, 230–235 (1965).Google Scholar
  43. Turner, W. B., and R. G. S. Bidwell: Rates of photosynthesis in attached and detached bean leaves and the effect of spraying with indoleacetic acid solution. Plant Physiol. 40, 446–451 (1965).Google Scholar
  44. Wardlaw, I. F.: The velocity and pattern of assimilate translocation in wheat plants during grain development. Aust. J. biol. Sci. 18, 269–281 (1965).Google Scholar
  45. Williams, R. D.: Assimilation and translocation in perennial grasses. Ann. Bot., N.S. 28, 419–427 (1964).Google Scholar
  46. Yakushkina, N. I., S. M. Poroiskaya, and T. G. Filatova: Some peculiarities of translocation of organic substances in plants and the influence of irrigation on this process. Fiziol. Rast. 3, 423–430 (1956).Google Scholar

Copyright information

© Springer-Verlag 1967

Authors and Affiliations

  • R. W. King
    • 1
  • I. F. Wardlaw
    • 1
  • L. T. Evans
    • 1
  1. 1.Division of Plant IndustryC.S.I.R.O.Canberra

Personalised recommendations