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 Travis, R. L. Articles by Ross, C. W. Search for Related Content PubMed PubMed Citation Articles by Travis, R. L. Articles by Ross, C. W. Agricola Articles by Travis, R. L. Articles by Ross, C. W.

Articles

Activation of 80S Maize Ribosomes by Red Light Treatment of Dark-grown Seedlings ¹

^a Department of Botany, University of Georgia, Athens, Georgia 30602

The in vitro protein synthetic activity of 80S ribosomes from leaves of dark-grown corn seedlings was enhanced (at low Mg²⁺ levels) by a 5-minute red light treatment applied 2 hours prior to tissue harvest. The effect was completely reversed by an immediate brief far red treatment, suggesting that ribosome activation is controlled by the phytochrome system. Experiments in which the interval between light treatment and tissue harvest was shortened indicate that the response was quite rapid. The initial increase in activity was detected within 30 minutes, followed by a rapid increase during the next 1.5 hours. No further increase occurred after 2 to 3 hours.

The change in ribosome activity relates, at least in part, to an increase in the level of peptidyl-tRNA associated with ribosomes. Removal of peptidyl-tRNA from light-treated ribosomes also completely reversed the red light effect. Activation of ribosomes by 2 to 3 hours continuous white light (as previously reported) differs from red light activation in that reversal of this response requires salt washing of the ribosomes in addition to removal of peptidyl-tRNA.

¹ This research was supported by Atomic Energy Commission Contract AT (38-1)-643 to J.L.K.