Hemmstoff und Wachstum: Growth Inhibitors, Not Auxin, Regulate Phototropism
Sixty years ago, a famous botanical dissertation appeared in The Netherlands: ‘Wuchsstoff und Wachstum’, by Frits W. Went . One of the classical experiments, described in this publication, was the unilateral illumination of an Avena sativa L. coleoptile tip, collecting the diffusates from the lighted and shaded sides in agar on either side of a flake of mica, and determining the auxin activities using the bioassay described in the paper (Fig. 1). From the auxin activity larger in the diffusate from the shaded side than from the lighted side, it was deduced that phototropic curvature results from differential flank growth caused by a lateral gradient in the cell-elongating substance. This auxin was later recognized as the ubiquitous IAA. The view was extended to gravitropism as the general Cholodny-Went theory of tropic curvature .
KeywordsHelianthus Annuus Auxin Activity Tropic Curvature Lateral Gradient Phototropic Response
Unable to display preview. Download preview PDF.
- 1.Blaauw AH (1915) Z Bot 7:465Google Scholar
- 9.Hasegawa K, Sakoda M (1988) Plant Cell Physiol 29:1159Google Scholar
- 13.Pickard BG (1985) In: Pharis RP, Reid DS (eds) Encyclopedia of plant physiology, new series, vol 11. Springer, Berlin Heidelberg New York Tokyo, p 365Google Scholar
- 14.Shen-Miller J, Knegt E, Vermeer E, Bruinsma J (1982) Z Pflanzenphysiol 108:289Google Scholar
- 17.Weiler EW (1988) Physiol Plant (in press)Google Scholar
- 18.Went FW (1928) Recl Trav Bot Neerl 25:1Google Scholar
- 19.Went FW, Thimann KV (1937) Phytohormones. MacMillan, New YorkGoogle Scholar