@misc{10481/99501,
year = {2013},
url = {https://hdl.handle.net/10481/99501},
abstract = {Nitrate and ammonium are major inorganic nitrogen sources for plants and algae. These compounds are assimilated by means of finely regulated processes at transcriptional and post-translational levels. In Chlamydomonas, the expression of several genes involved in high-affinity ammonium (AMT1.1, AMT1.2) and nitrate transport (NRT2.1) as well as nitrate reduction (NIA1) are downregulated by ammonium through a nitric oxide (NO)-dependent mechanism. At the post-translational level, nitrate/nitrite uptake and nitrate reductase (NR) are also inhibited by ammonium, but the mechanisms implicated in this regulation are scarcely known. In this work, the effect of NO on nitrate assimilation and the high-affinity ammonium uptake was addressed. NO inhibited the high-affinity uptake of ammonium and nitrate/nitrite, as well as the NR activity, in a reversible form. In contrast, nitrite reductase and glutamine synthetase activities were not affected. The in vivo and in vitro studies suggested that NR enzyme is inhibited by NO in a mediated process that requires the cell integrity. These data highlight a role of NO in inorganic nitrogen assimilation and suggest that this signalling molecule is an important regulator for the first steps of the pathway.},
organization = {This work was funded by MINECO (Ministerio de Economia y Competitividad, Spain , grant no. BFU2011-29338) with the support of the European FEDER programme, Junta de Andalucía (P08-CVI-04157), and Plan Propio de la Universidad de Córdoba. The authors thank Maribel Macías for skilful technical assistance. F.O.-C. thanks MINECO for a ‘Formación de Personal Investigador’ fellowship.},
publisher = {Oxford Academy},
keywords = {Ammonium uptake, Chlamydomonas, glutamine synthetase, nitrate and nitrite uptake, nitrate reductase, nitric oxide, nitrite reductase, post-translational regulation.},
title = {Nitric oxide controls nitrate and ammonium assimilation in Chlamydomonas reinhardtii},
doi = {https://doi.org/10.1093/jxb/ert175},
author = {Ocaña Calahorro, Francisco Javier},
}