|
 |
|
|
|
EMBO reports 5, 8, 801–806 (2004)
doi:10.1038/sj.embor.7400202
Published online: 16 July 2004
Analysis of developing maize plastids reveals two mRNA stability classes correlating with RNA polymerase type
A Bruce Cahoon, Faith M Harris & David B Stern
|
|
|
|
Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, New York 14853 USA, A Bruce Cahoon's Present address: Department of Biology, Box 60, Middle Tennessee State University, Murfreesboro, Tennessee 37130, USA
To whom correspondence should be addressed
David B Stern Tel: +1 607 254 1306; Fax: +1 607 255 6695; E-mail: acahoon@mtsu.edu or ds28@cornell.edu
Received 28 August 2003; Accepted 16 June 2004; Published online 16 July 2004.
|
|
|
|
Abstract
The plastid genome is transcribed by two distinct RNA polymerases, the PEP encoded by the plastid genome and the NEP encoded in the nucleus. Initial models of plastid transcription held that the NEP is responsible for the transcription of housekeeping genes needed early in development, and that the PEP transcribes genes required for photosynthesis. Recently, this model was challenged by the discovery that all plastid genes are transcribed by NEP in PEP-deficient tobacco plastids, suggesting that mRNA turnover may have a strong role in previously observed transcription patterns. In this study, we provide evidence that the NEP enzyme level decreases as plastids mature. In contrast, production of mRNAs by NEP increases as plastids mature, yet their accumulations remain constant. These results suggest that as plastids mature NEP may become more active, and that mRNA turnover varies between transcripts synthesized by NEP and PEP.
|
|
top  |
|
|
|
