This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kang, B. G. Articles by Burg, S. P. Search for Related Content PubMed PubMed Citation Articles by Kang, B. G. Articles by Burg, S. P. Agricola Articles by Kang, B. G. Articles by Burg, S. P.

Articles

Relation of Phytochrome-enhanced Geotropic Sensitivity to Ethylene Production ¹

^a The Fairchild Tropical Garden, Miami, Florida 33156, Department of Biology, University of Miami, Miami, Florida 33124

Brief exposure of etiolated pea (Pisum sativum cv. Alaska) seedlings to red light enhances subsequent development of geotropic curvature of the stem. Both this response and inhibition of ethylene production by red light become maximal 8 hours after illumination. Very low concentrations of applied ethylene inhibit development of geotropic curvature, whereas hypobaric treatment enhances geotropic sensitivity by removing endogenous ethylene. Increased geotropic sensitivity after illumination is accompanied by increased lateral migration of ³H-indoleacetic acid in response to gravity, and ethylene inhibits this lateral migration. It is suggested, therefore, that red light-enhanced geotropic sensitivity is caused by increased lateral auxin transport resulting from a reduction in ethylene production after illumination.