Differential impact of amino acids on OXPHOS system activity following carbohydrate starvation in Arabidopsis cell suspensions

authored by: João Henrique F. Cavalcanti, Carla G.S. Quinhones, Peter Schertl, Danielle S. Brito, Holger Eubel, Tatjana Hildebrandt, Adriano Nunes-Nesi, Hans Peter Braun, Wagner L. Araújo
Abstract: Plant respiration mostly depends on the activity of glycolysis and the oxidation of organic acids in the tricarboxylic acid cycle to synthesize ATP. However, during stress situations plant cells also use amino acids as alternative substrates to donate electrons through the electron-transfer flavoprotein (ETF)/ETF:ubiquinone oxidoreductase (ETF/ETFQO) complex to the mitochondrial electron transport chain (mETC). Given this, we investigated changes of the oxidative phosphorylation (OXPHOS) system in Arabidopsis thaliana cell culture under carbohydrate starvation supplied with a range of amino acids. Induction of isovaleryl-CoA dehydrogenase (IVDH) activity was observed under carbohydrate starvation which was associated with increased amounts of IVDH protein detected by immunoblotting. Furthermore, activities of the protein complexes of the mETC were reduced under carbohydrate starvation. We also observed that OXPHOS system activity behavior is differently affected by different amino acids and that proteins associated with amino acids catabolism are upregulated in cells following carbohydrate starvation. Collectively, our results support the contention that ETF/ETFQO is an essential pathway to donate electrons to the mETC and that amino acids are alternative substrates to maintain respiration under carbohydrate starvation.
Organisation(s): Institute of Plant Genetics
External Organisation(s): Universidade Federal de Vicosa
Type: Article
Journal: Physiologia plantarum
Volume: 161
Pages: 451-467
No. of pages: 17
ISSN: 0031-9317
Publication date: 02.08.2017
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Physiology, Genetics, Plant Science, Cell Biology
Electronic version(s): https://doi.org/10.1111/ppl.12612 (Access: Unknown)