Effect of assimilate utilization on photosynthetic rate in wheat
Rent the article at a discountRent now
* Final gross prices may vary according to local VAT.Get Access
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.
- 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).
- Andersson, G.: Gas exchange and frost hardening studies in winter cereals. Gleerupska. Lund: Univ. bokhand. 1944.
- 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).
- Bakhuyzen, H. L. Van der Sande: Bloei en bloeihormonen in het bijzonder bij tarwe. I. Minist. Landb. Verslag Onderz. 53, 145–212 (1947).
- 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).
- Bierhuizen, J. F., R. O. Slatyer, and C. W. Rose: A porometer for laboratory and field operation. J. Exp. Bot. 16, 182–191 (1965).
- Bingham, J.: Paternal effect of grain size in wheat. Nature (Lond.) 209, 940–941 (1966).
- 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).
- 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).
- Burt, R. L.: Carbohydrate utilization as a factor in plant growth. Aust. J. biol. Sci. 17, 867–877 (1964).
- Crafts, A. S.: The chemistry and mode of action of herbicides. New York: Interscience Publ. 1961.
- Davies, C. R., and P. F. Wareing: Auxin-directed transport of radiophosphorus in stems. Planta (Berl.) 65, 139–156 (1965).
- 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).
- 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).
- Ewart, A. J.: On assimilatory inhibition in plants. J. Linnean Soc. Bot. 31, 364–461 (1896).
- Hartt, C.: Translocation as a factor in photosynthesis. Naturwissenschaften 50, 666–667 (1963).
- 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).
- Humphries, E. C.: Dependence of net assimilation rate on root growth of isolated leaves. Ann. Bot., NS. 27, 175–183 (1963).
- Humphries, E. C., and G. N. Thorne: The effect of root formation on photosynthesis of detached leaves. Ann. Bot., NS. 28, 391–400 (1964).
- Jenkins, H. V.: An airflow planimeter for measuring the area of detached leaves. Plant Physiol. 34, 532–536 (1959).
- Kende, H.: Kinetin-like factors in the root exudate of sunflowers. Proc. nat. Acad. Sci. (Wash.) 53, 1302–1307 (1965).
- Kiesselbach, T. A.: Endosperm type as a physiological factor in corn yields. J. Amer. Soc. Agron. 40, 216–236 (1948).
- 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).
- Kurssanow, A. L.: Die Photosynthese grüner Früchte und ihre Abhängigkeit von der normalen Tätigkeit der Blätter. Planta (Berl.) 22, 240–250 (1934).
- 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).
- Moss, D. N.: Photosynthesis and barrenness. Crop. Sci. 2, 366 (1962).
- 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).
- 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).
- Pescod, D., W. R. Read, and D. W. Cunliffe: Engineering aspects of environment control for plant growth, p. 175–183. Melbourne: CSIRO 1962.
- Ponigrahi, B. M., and L. J. Audus: Apical dominance in Vicia faba. Ann. Bot., N.S. 30, 457–473 (1966).
- Povolotskaya, K. L., Y. V. Rakitin, and I. V. Khovanskaya: Role of heteroauxin in sugar translocation. Fiziol. Rast. 9, 303–308 (1962).
- 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).
- Richmond, A. E., and A. Lang: Effect of kinetin on protein content and survival of detached Xanthium leaves. Science 125, 650–651 (1957).
- 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).
- 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).
- 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).
- Stoy, V.: Photosynthesis, respiration, and carbohydrate accumulation in spring wheat in relation to its yield. Physiol. Plant. (København), Suppl. 4, 1–125 (1965).
- Sweet, G. B., and P. F. Wareing: Role of plant growth in regulating photosynthesis. Nature (Lond.) 210, 77–79 (1966).
- 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.
- —, 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).
- 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).
- Tsuno, Y., and K. Fujise: Studies on the dry matter production of the sweet potato. Proc. Crop Sci. Soc. Japan 33, 230–235 (1965).
- 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).
- Wardlaw, I. F.: The velocity and pattern of assimilate translocation in wheat plants during grain development. Aust. J. biol. Sci. 18, 269–281 (1965).
- Williams, R. D.: Assimilation and translocation in perennial grasses. Ann. Bot., N.S. 28, 419–427 (1964).
- 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).
- Effect of assimilate utilization on photosynthetic rate in wheat
Volume 77, Issue 3 , pp 261-276
- Cover Date
- Print ISSN
- Online ISSN
- Additional Links
- Industry Sectors