An Auxin-like Action of Coumarin

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Science  19 Jun 1959:
Vol. 129, Issue 3364, pp. 1675-1676
DOI: 10.1126/science.129.3364.1675


Coumarin, usually regarded as an inhibitor of growth processes in plants, markedly stimulated the elongation of excised segments of Helianthus hypocotyls. Substitution in the molecule of hydroxy-, methyl-, or chloro-groups, in the neighborhood of the unsaturated bond in the lactone ring, markedly altered the growth-promoting activity.