MCB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lissemore, J L
Right arrow Articles by Quail, P H
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lissemore, J L
Right arrow Articles by Quail, P H

 Previous Article  |  Next Article 

Mol Cell Biol. 1988 November; 8(11): 4840-4850

Rapid transcriptional regulation by phytochrome of the genes for phytochrome and chlorophyll a/b-binding protein in Avena sativa.

J L Lissemore and P H Quail

Department of Botany, University of Wisconsin, Madison.

ABSTRACT

We have examined phytochrome-regulated transcription of phytochrome (phy) and chlorophyll a/b binding protein (cab) genes in dark-grown Avena seedlings by using run-on transcription in isolated nuclei. Kinetic analysis of phy transcription following pulse-light treatments to produce various amounts of Pfr, the active form of phytochrome, leads to these conclusions. (i) Transcription decreases rapidly (discernible within 5 min) after Pfr formation, reaching an essentially undetectable level by 1 h. (ii) The response is very sensitive; less than 1% Pfr is sufficient to produce maximum feedback repression over the first 30 min. (iii) The duration of transcriptional repression is proportional to the Pfr concentration; derepression begins once the concentration falls below some saturation level because of degradation of Pfr. Concurrent analysis of cab transcription leads to these conclusions. (i) After Pfr formation, transcription increases approximately 10-fold by 3 h, but this response is not detectable until after a 30-min lag. (ii) Detectable induction of cab requires a greater than 30-fold-higher Pfr level than is needed to repress phy expression. (iii) Transcription returns to the preirradiation level considerably sooner than does phy transcription (less than 12 h versus greater than 24 h respectively), indicating that a high level of Pfr is needed to sustain the increased transcription of cab. Taken together, these results suggest that differences in the phytochrome signal transduction pathway are responsible for the distinct patterns of regulation of these genes. Full repression of phy occurs even when protein synthesis is inhibited greater than 90% by cycloheximide and chloramphenicol. In conjunction with the rapidity of the response to Pfr, this result provides evidence that feedback repression of phy gene transcription does not require expression of an intervening regulatory gene(s). Thus, phy is the first gene for which there is evidence for direct control of transcription by the phytochrome signal transduction chain.

Mol Cell Biol. 1988 November; 8(11): 4840-4850




This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. J. Virol. Eukaryot. Cell
Microbiol. Mol. Biol. Rev. Clin. Vaccine Immunol. All ASM Journals

Copyright © 1988 by the American Society for Microbiology. All rights reserved.