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Reorganization of the alternative pathways of the Arabidopsis respiratory chain by nitrogen supply: opposing effects of ammonium and nitrate

Escobar, Matthew LU ; Geisler, Daniela LU and Rasmusson, Allan LU (2006) In Plant Journal 45(5). p.775-788
Abstract
The mitochondrial oxidative phosphorylation system in plants possesses a variety of alternative pathways that decrease respiratory ATP production. These alternative pathways are mediated by three classes of bypass proteins: the type II NAD(P) H dehydrogenases (which circumvent complex I of the electron transport chain), the alternative oxidases (AOXs; which circumvent complexes III and IV) and the uncoupling proteins ( which circumvent ATP synthase). We have monitored the expression of all genes encoding respiratory bypass proteins in Arabidopsis thaliana growing with different sources of inorganic nitrogen (N). Resupply of nitrate (NO3-) to N-limited seedling cultures caused a decrease in the transcript abundance of several type II NAD(P)... (More)
The mitochondrial oxidative phosphorylation system in plants possesses a variety of alternative pathways that decrease respiratory ATP production. These alternative pathways are mediated by three classes of bypass proteins: the type II NAD(P) H dehydrogenases (which circumvent complex I of the electron transport chain), the alternative oxidases (AOXs; which circumvent complexes III and IV) and the uncoupling proteins ( which circumvent ATP synthase). We have monitored the expression of all genes encoding respiratory bypass proteins in Arabidopsis thaliana growing with different sources of inorganic nitrogen (N). Resupply of nitrate (NO3-) to N-limited seedling cultures caused a decrease in the transcript abundance of several type II NAD(P) H dehydrogenase and AOX genes, while resupply of ammonium (NH4+) led to broad increases in expression in the same gene families. Similar results were observed upon switching between nitrate and ammonium in the absence of N stress. Nitrate signalling was found to be mediated primarily by the nitrate ion itself, whereas ammonium regulation was dependent upon assimilation and affected by changes in apoplastic pH. Corresponding alterations in alternative respiratory pathway capacities were apparent in seedlings supplied with either nitrate or ammonium as an N source and in mitochondria purified from the seedlings. Specifically, AOX capacity and protein abundance, as well as calcium-dependent external NADH oxidation, were substantially elevated after growth on ammonium. The increased capacity of respiratory bypass pathways after switching from nitrate to ammonium was correlated to an overall respiratory increase. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
mitochondria, plant, nitrate, NAD(P)H dehydrogenase, alternative oxidase, ammonium, respiratory chain
in
Plant Journal
volume
45
issue
5
pages
775 - 788
publisher
Wiley-Blackwell
external identifiers
  • pmid:16460511
  • wos:000235168400007
  • scopus:33644867727
  • pmid:16460511
ISSN
1365-313X
DOI
10.1111/j.1365-313X.2005.02640.x
language
English
LU publication?
yes
id
a9dddbe3-4a6e-4429-90ab-f6f7c6c4457a (old id 417670)
date added to LUP
2016-04-01 16:02:56
date last changed
2020-07-01 03:11:47
@article{a9dddbe3-4a6e-4429-90ab-f6f7c6c4457a,
  abstract     = {The mitochondrial oxidative phosphorylation system in plants possesses a variety of alternative pathways that decrease respiratory ATP production. These alternative pathways are mediated by three classes of bypass proteins: the type II NAD(P) H dehydrogenases (which circumvent complex I of the electron transport chain), the alternative oxidases (AOXs; which circumvent complexes III and IV) and the uncoupling proteins ( which circumvent ATP synthase). We have monitored the expression of all genes encoding respiratory bypass proteins in Arabidopsis thaliana growing with different sources of inorganic nitrogen (N). Resupply of nitrate (NO3-) to N-limited seedling cultures caused a decrease in the transcript abundance of several type II NAD(P) H dehydrogenase and AOX genes, while resupply of ammonium (NH4+) led to broad increases in expression in the same gene families. Similar results were observed upon switching between nitrate and ammonium in the absence of N stress. Nitrate signalling was found to be mediated primarily by the nitrate ion itself, whereas ammonium regulation was dependent upon assimilation and affected by changes in apoplastic pH. Corresponding alterations in alternative respiratory pathway capacities were apparent in seedlings supplied with either nitrate or ammonium as an N source and in mitochondria purified from the seedlings. Specifically, AOX capacity and protein abundance, as well as calcium-dependent external NADH oxidation, were substantially elevated after growth on ammonium. The increased capacity of respiratory bypass pathways after switching from nitrate to ammonium was correlated to an overall respiratory increase.},
  author       = {Escobar, Matthew and Geisler, Daniela and Rasmusson, Allan},
  issn         = {1365-313X},
  language     = {eng},
  number       = {5},
  pages        = {775--788},
  publisher    = {Wiley-Blackwell},
  series       = {Plant Journal},
  title        = {Reorganization of the alternative pathways of the Arabidopsis respiratory chain by nitrogen supply: opposing effects of ammonium and nitrate},
  url          = {http://dx.doi.org/10.1111/j.1365-313X.2005.02640.x},
  doi          = {10.1111/j.1365-313X.2005.02640.x},
  volume       = {45},
  year         = {2006},
}