Nitrite reductase expression is regulated at the post-transcriptional level by the nitrogen source in Nicotiana plumbaginifolia and Arabidopsis thaliana
Article first published online: 5 MAR 2002
The Plant Journal
Volume 11, Issue 4, pages 625–634, April 1997
How to Cite
Crété, P., Caboche, M. and Meyer, C. (1997), Nitrite reductase expression is regulated at the post-transcriptional level by the nitrogen source in Nicotiana plumbaginifolia and Arabidopsis thaliana. The Plant Journal, 11: 625–634. doi: 10.1046/j.1365-313X.1997.11040625.x
- Issue published online: 5 MAR 2002
- Article first published online: 5 MAR 2002
- Received 15 January 1996; revised 28 November 1996; accepted 14 December 1996.
- Cited By
Higher plant nitrite reductase (NiR) is a monomeric chloroplastic protein catalysing the reduction of nitrite, the product of nitrate reduction, to ammonium. The expression of this enzyme is controlled at the transcriptional level by light and by the nitrogen source. In order to study the post-transcriptional regulation of NiR, Nicotiana plumbaginifolia and Arabidopsis thaliana were transformed with a chimaeric NiR construct containing the tobacco leaf NiR1 coding sequence driven by the CaMV 35S RNA promoter. Transformed plants did not show any phenotypic difference when compared with the wild-type, although they overexpressed NiR activity in the leaves. When these plants were grown in vitro on media containing either nitrate or ammonium as sole nitrogen source, NiR mRNA derived from transgene expression was constitutively expressed, whereas NiR activity and protein level were strongly reduced on ammonium-containing medium. These results suggest that, together with transcriptional control, post-transcriptional regulation by the nitrogen source is operating on NiR expression. This post-transcriptional regulation of tobacco leaf NiR1 expression was observed not only in the closely related species N. plumbaginifolia but also in the more distant species A. thaliana.