The movement of 2,4-Dichlorophenoxy acetic acid (2,4-D) through subapical segments of the primary roots of Pisum seedlings has been investigated using [1-14C]2,4-D.
Donation of [1-14C]2,4-D to the apical or basal ends of Pisum root segments at 25°C in darkness revealed a preferential movement of the compound towards the root apex i.e. an acropetal polarisation. Thus the movement of [1-14C]2,4-D into receiver blocks applied to the apical ends of the segments is greater than that into receiver blocks applied to the basal ends of the segments The low level of basipetal transport appears to be associated with a restriction of the movement of [1-14C]2,4-D to the half of the segment nearest the donor block.
Acropetal transport of 2,4-D is faster than basipetal transport in root segments maintained at 15° and 35° C but is slower than basipetal transport if the segments are maintained at 25°C. Maximum velocitees are 0.71 and 0.83 mm h-1 for acropetal and basipetal transport respectively.
Evidence from experiments carried out (a) in an anaerobic environment in the presence or absence of sodium fluoride and (b) over a range of temperatures from 1–35°C, indicates that the movement of [1-14C]2,4-D is dependent on the metabolic activity of the Pisum root segments.
Release of 14CO2 during transport of [1-14C]2,4-D is small and supports chromatographic evidence that negligible degradation of the 2,4-D molecules takes place during transport through the root segments.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Aasheim, T., Iversen, T.-H.: Decarboxylation and transport of auxin in segments of sunflower and cabbage roots. II. A chromatographic study using IAA-1-14C and IAA-5-3H. Physiol. Plant. 24, 325–329 (1971)
Bonnett, H. T., Torrey, J. G.: Auxin transport in Convolvulus roots cultured in vitro. Plant Physiol. 40, 813–818 (1965)
Christie, A. E., Leopold, A. C.: On the manner of triiodobenzoic acid inhibition of auxin transport. Plant Cell Physiol. 6, 337–345 (1965a)
Christie, A. E., Leopold, A. C.: Entry and exit of indoleacetic acid in corn coleoptiles. Plant Cell Physiol. 6, 453–465 (1965b)
Davies, P., Mitchell, E.: Transport of indoleacetic acid in intact roots of Phaseolus coccineus. Planta (Berl.) 105, 139–154 (1972)
Galston, A. W., Dalberg, L. Y.: The adaptive formation and physiological significance of indole-acetic acid oxidase. Amer. J. Bot. 41 373–380 (1954)
Hillman, S. K., Phillips, I. D. J.: Transport and metabolism of indol-3yl-(acetic acid-2-14C) in pea roots. J. exp. Bot. 21 959–967 (1970)
Iversen, T.-H., Aasheim, T.: Decarboxylation and transport of auxin in segments of sunflower and cabbage roots. Planta (Berl.) 93, 354–362 (1970)
Iversen, T.-H., Aasheim, T., Pedersen, K.: Transport and degradation of auxin in relation to geotropism of roots of Phaseolus vulgaris Physiol. Plant. 25 417–424 (1971)
Kirk, S. C., Jacobs, W. P.: Polar movement of indole-3-acetic acid-14C in roots of Lens and Phaseolus. Plant Physiol. 43, 675–682 (1968)
Konings, H., Gayadin, A. P.: Transport, binding and decarboxylation of carboxyl-labelled IAA-14C in intact pea roots. Acta bot. neerl 20, 646–654 (1971)
McCready, C. C., Jacobs, W. P.: Movement of growth regulators in plants II. Polar transport of radioactivity from indoleacetic acid-(14C) and 2,4-dichlorophenoxyacetic acid-(14C) in petioles of Phaseolus vulgaris. New Phytol. 62 19–34 (1963)
Pilet, P. E.: Auxin transport in roots: Lens culinaris. Nature (Lond.) 204, 561–562 (1964)
Wilkins, H.: The movement and metabolism of 2,4-dichlorophenoxy-acetic acid in root tissues of Pisum sativum L. Ph. D. Thesis of the University of Glasgow (1974)
Wilkins, M. B., Cane, A. R.: Auxin transport in roots. V. Effects of temperature on the movement of IAA in Zea roots. J. exp. Bot. 21 195–211 (1970)
Wilkins, M. B., Cane, A. R., McCorquodale, I.: Auxin transport in roots. VII. Uptake and movement of radioactivity from IAA-14C by Zea roots. Planta (Berl.) 105,93–113 (1972a)
Wilkins, M. B., Cane, A. R., McCorquodale, I.: Auxin transport in roots. IX. Movement, export, resorption and loss of radioactivity from IAA by Zea root segments. Planta (Berl.) 106, 291–310 (1972b)
Wilkins, M. B., Scott, T. K.: Auxin transport in roots. Nature (Lond.) 219, 1388–1389 (1968a)
Wilkins, M. B., Scott, T. K.: Auxin transport in roots. III. Dependence of the polar flux of IAA in Zea roots upon metabolism. Planta (Berl.) 83 335–346 (1968b)
Wilkins, M. B., Whyte, P.: Polar transport of auxin in Zea coleoptiles under anaerobic conditions. Planta (Berl.) 82, 307–316 (1968)
Winter, A.: The promotion of the immobilisation of auxin in Avena coleoptiles by triiodobenzoic acid. Physiol. Plant 20, 330–336 (1967)
Yeomans, L. M., Audus, L. J.: Auxin transport in roots: Vicia faba. Nature (Lond.) 204, 559–561 (1964)
About this article
Cite this article
Wilkins, H., Wilkins, M.B. The movement of 2,4-dichlorophenoxy acetic acid in root segments of Pisum sativum L.. Planta 124, 177–189 (1975). https://doi.org/10.1007/BF00384760
- Acetic Acid
- Metabolic Activity
- Receiver Block
- Primary Root