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. 1981 Dec;68(6):1334–1338. doi: 10.1104/pp.68.6.1334

Evidence for Receptor Function of Auxin Binding Sites in Maize 1

RED LIGHT INHIBITION OF MESOCOTYL ELONGATION AND AUXIN BINDING

Jonathan D Walton 1,2, Peter M Ray 1
PMCID: PMC426098  PMID: 16662103

Abstract

When 3- to 4-day-old dark-grown maize (Zea mays L. WF9 × Bear 38) seedlings are given red light, auxin-binding activity localized on endoplasmic reticulum membranes of the mesocotyl begins to decrease after 4 hours; by 9 hours, it falls to 50 to 60% of that in dark controls, on either a fresh weight or total particulate protein basis. Endoplasmic reticulum-localized NADH:cytochrome c reductase activity decreases in parallel. Loss of binding is due to decrease in number of sites, with no change in their affinity for auxin (Kd 0.2 micromolar for naphthalene-1-acetic acid). Elongation of mesocotyl segments in response to auxin decreases with a similar time course. Elongation of segments from irradiated plants shows the same apparent affinity for auxin as that of the dark controls. Auxin-binding activity and elongation response also decrease in parallel down the length of the mesocotyl. These observations are consistent with a role of endoplasmic reticulum-localized auxin binding sites as receptors for auxin action in cell elongation.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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