AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
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 You, M.
Right arrow Articles by Minamisawa, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by You, M.
Right arrow Articles by Minamisawa, K.
Agricola
Right arrow Articles by You, M.
Right arrow Articles by Minamisawa, K.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, December 2005, p. 8183-8190, Vol. 71, No. 12
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.12.8183-8190.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.

Expression of the nifH Gene of a Herbaspirillum Endophyte in Wild Rice Species: Daily Rhythm during the Light-Dark Cycle

Mu You, Tomohiro Nishiguchi, Asami Saito, Tsuyoshi Isawa, Hisayuki Mitsui, and Kiwamu Minamisawa*

Graduate School of Life Sciences, Tohoku University, Katahira, Aoba-ku, Sendai 980-8577, Japan

Received 10 January 2005/ Accepted 28 July 2005

The expression of nitrogenase genes of Herbaspirillum sp. B501 associated in shoot (leaf and stem) of wild rice, Oryza officinalis, was studied by means of reverse transcription-PCR (RT-PCR) targeted at the nifH gene. RT-PCR analyses indicate that nifH transcript was detected exclusively from nitrogen-fixing cells of gfp-tagged strain B501gfp1 in both free-living and endophytic states by using a constitutive gfp gene transcript as a positive control. Transcription of nifH and nitrogen fixation in free-living cells were induced maximally at a 2% O2 concentration and repressed in free air (21% O2). nifH transcription was monitored in the endophytic cells by using total RNA extracted from B501gfp1-inoculated wild rice plants during daily light-dark cycles. The level of nifH transcription in planta varied dramatically, with a maximum during the light period. Moreover, the light radiation enhanced nifH expression even in free-living cells grown in culture. These results suggest that in planta nitrogen fixation by the endophyte shows a daily rhythm determined by the plant's light environment.

* Corresponding author. Mailing address: Graduate School of Life Sciences, Tohoku University, Katahira, Aoba-ku, Sendai 980-8577, Japan. Phone: 81-22-217-5684. Fax: 81-22-217-5684. E-mail: kiwamu{at}ige.tohoku.ac.jp.

Applied and Environmental Microbiology, December 2005, p. 8183-8190, Vol. 71, No. 12
0099-2240/05/$08.00+0     doi:10.1128/AEM.71.12.8183-8190.2005
Copyright © 2005, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



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

Copyright © 2005 by the American Society for Microbiology. All rights reserved.