OPEN ACCESS ARTICLE

This Article Free via Open Access: OA OA Full Text Full Text (PDF) OA All Versions of this Article: 142/2/642    most recent pp.106.085878v1 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 Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Loschelder, H. Articles by Link, G. Search for Related Content PubMed PubMed Citation Articles by Loschelder, H. Articles by Link, G. Agricola Articles by Loschelder, H. Articles by Link, G.

SYSTEMS BIOLOGY, MOLECULAR BIOLOGY, AND GENE REGULATION

Dual Temporal Role of Plastid Sigma Factor 6 in Arabidopsis Development^1,[OA]

Plant Cell Physiology, University of Bochum, D–44780 Bochum, Germany

Plants contain nuclear-coded sigma factors for initiation of chloroplast transcription. The in vivo function of individual members of the sigma gene family has become increasingly accessible by knockout and complementation strategies. Here we have investigated plastid gene expression in an Arabidopsis (Arabidopsis thaliana) mutant with a defective gene for sigma factor 6. RNA gel-blot hybridization and real-time reverse transcription polymerase chain reaction together indicate that this factor has a dual developmental role, with both early and persistent (long-term) activities. The early role is evident from the sharp decrease of certain plastid transcripts only in young mutant seedlings. The second (persistent) role is reflected by the up- and down-regulation of other transcripts at the time of primary leaf formation and subsequent vegetative development. We conclude that sigma 6 does not represent a general factor, but seems to have specialized roles in developmental stage- and gene-specific plastid transcription. The possibility that plastid DNA copy number might be responsible for the altered transcript patterns in mutant versus wild type was excluded by the results of DNA gel-blot hybridization. Retransformation of the knockout line with the full-length sigma 6 cDNA further established a causal relationship between the functional sigma gene and the resulting phenotype.

The author responsible for distribution of materials integral to the findings presented in this article in accordance with the policy described in the Instructions for Authors (www.plantphysiol.org) is: Gerhard Link (gerhard.link{at}ruhr-uni-bochum.de).

^[OA] Open Access articles can be viewed online without a subscription.

www.plantphysiol.org/cgi/doi/10.1104/pp.106.085878

^* Corresponding author; e-mail gerhard.link{at}ruhr-uni-bochum.de; fax 49–234–3214–188.

Received June 27, 2006; accepted August 1, 2006; published August 11, 2006.

This article has been cited by other articles:

				N. S. Coll, A. Danon, J. Meurer, W. K. Cho, and K. Apel Characterization of soldat8, a Suppressor of Singlet Oxygen-Induced Cell Death in Arabidopsis Seedlings Plant Cell Physiol., April 1, 2009; 50(4): 707 - 718. [Abstract] [Full Text] [PDF]

				Y. Kubota, A. Miyao, H. Hirochika, Y. Tozawa, H. Yasuda, Y. Tsunoyama, Y. Niwa, S. Imamura, M. Shirai, and M. Asayama Two Novel Nuclear Genes, OsSIG5 and OsSIG6, Encoding Potential Plastid Sigma Factors of RNA Polymerase in Rice: Tissue-Specific and Light-Responsive Gene Expression Plant Cell Physiol., January 1, 2007; 48(1): 186 - 192. [Abstract] [Full Text] [PDF]