Permanent address: Biology Department, Princeton University, Princeton, New Jersey.
MOVEMENT OF GROWTH REGULATORS IN PLANTS
II. POLAR TRANSPORT OF RADIOACTIVITY FROM INDOLEACETIC ACID-[14C] AND 2,4-DICHLOROPHENOXY-ACETIC ACID-[14C] IN PETIOLES OF PHASEOLUS VULGARIS
Article first published online: 2 MAY 2006
Volume 62, Issue 1, pages 19–34, April 1963
How to Cite
McCREADY, C. C. and JACOBS, W. P. (1963), MOVEMENT OF GROWTH REGULATORS IN PLANTS. New Phytologist, 62: 19–34. doi: 10.1111/j.1469-8137.1963.tb06308.x
(With 7 figures in the text)
- Issue published online: 2 MAY 2006
- Article first published online: 2 MAY 2006
- (Received 21 August 1962)
The movement of radioactivity added in the form of indoleacetic acid (as the natural hormone) or as 2,4-dichlorophenoxyacetic acid (as a synthetic growth regulator) was followed in segments cut from petioles of Phaseolus vulgaris.
The movement of 14C added as IAA was strongly basipetally polar, although significant amounts moved acropetally during 24 hours. The velocity of basipetal movement was 6 mm/hour for IAA-[14C], and was the same for donor concentrations of 5 or 50 μM. The flux increased with increasing concentration in the donor blocks, but a progressively smaller percentage of the applied radioactivity was transported.
2,4-D-[14C] was found to have very similar transport properties to those of IAA-[14C], except that its velocity of basipetal movement was much less, namely 1 mm/hour. After correction had been made for the much slower net loss of 2,4-D from its donor blocks, the acropetal movement of the 14C from the two substances was essentially the same.