The role of the electron-transfer flavoprotein

ubiquinone oxidoreductase following carbohydrate starvation in Arabidopsis cell cultures

authored by
Danielle S Brito, Carla G S Quinhones, Roberto Neri-Silva, Björn Heinemann, Peter Schertl, João Henrique F Cavalcanti, Holger Eubel, Tatjana Hildebrandt, Adriano Nunes-Nesi, Hans-Peter Braun, Wagner L Araújo

KEY MESSAGE: The functional absence of the electron-transfer flavoprotein: ubiquinone oxidoreductase (ETFQO) directly impacts electrons donation to the mitochondrial electron transport chain under carbohydrate-limiting conditions without major impacts on the respiration of cell cultures. Alternative substrates (e.g., amino acids) can directly feed electrons into the mitochondrial electron transport chain (mETC) via the electron transfer flavoprotein/electron-transfer flavoprotein: ubiquinone oxidoreductase (ETF/ETFQO) complex, which supports plant respiration during stress situations. By using a cell culture system, here we investigated the responses of Arabidopsis thaliana mutants deficient in the expression of ETFQO (etfqo-1) following carbon limitation and supplied with amino acids. Our results demonstrate that isovaleryl-CoA dehydrogenase (IVDH) activity was induced during carbon limitation only in wild-type and that these changes occurred concomit with enhanced protein content. By contrast, neither the activity nor the total amount of IVDH was altered in etfqo-1 mutants. We also demonstrate that the activities of mitochondrial complexes in etfqo-1 mutants, display a similar pattern as in wild-type cells. Our findings suggest that the defect of ETFQO protein culminates with an impaired functioning of the IVDH, since no induction of IVDH activity was observed. However, the functional absence of the ETFQO seems not to cause major impacts on plant respiration under carbon limiting conditions, most likely due to other alternative electron entry pathways.

Institute of Plant Genetics
External Organisation(s)
Universidade Federal de Vicosa
Universidade Federal do Amazonas
Plant cell reports
No. of pages
Publication date
Publication status
Peer reviewed
ASJC Scopus subject areas
Agronomy and Crop Science, Plant Science
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