title: The influence of alternative pathways of respiration that utilize branched-chain amino acids following water shortage in Arabidopsis.
abstract: During dark-induced senescence isovaleryl-CoA dehydrogenase (IVDH) and D-2-hydroxyglutarate dehydrogenase (D-2HGDH) act as alternate electron donors to the ubiquinol pool via the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase (ETF/ETFQO) pathway. However, the role of this pathway in response to other stresses still remains unclear. Here, we demonstrated that this alternative pathway is associated with tolerance to drought in Arabidopsis. In comparison with wild type (WT) and lines overexpressing D-2GHDH, loss-of-function etfqo-1, d2hgdh-2 and ivdh-1 mutants displayed compromised respiration rates and were more sensitive to drought. Our results demonstrated that an operational ETF/ETFQO pathway is associated with plants' ability to withstand drought and to recover growth once water becomes replete. Drought-induced metabolic reprogramming resulted in an increase in tricarboxylic acid (TCA) cycle intermediates and total amino acid levels, as well as decreases in protein, starch and nitrate contents. The enhanced levels of the branched-chain amino acids in loss-of-function mutants appear to be related to their increased utilization as substrates for the TCA cycle under water stress. Our results thus show that mitochondrial metabolism is highly active during drought stress responses and provide support for a role of alternative respiratory pathways within this response.
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.|Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil.
authors.forename: Marcel V
authors.initials: MV
authors.lastname: Pires
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Adilson A
authors.initials: AA
authors.lastname: Pereira Júnior
authors.affiliation: Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil.
authors.forename: David B
authors.initials: DB
authors.lastname: Medeiros
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.|Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil.
authors.forename: Danilo M
authors.initials: DM
authors.lastname: Daloso
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Phuong Anh
authors.initials: PA
authors.lastname: Pham
authors.affiliation: Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil.
authors.forename: Kallyne A
authors.initials: KA
authors.lastname: Barros
authors.affiliation: Plant Molecular Physiology and Biotechnology, Institute of Plant Developmental and Molecular Biology, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstr 1, D-40225, Düsseldorf, Germany.|Department of Chemical and Biological Engineering, Chalmers University of Technology, Göterborg, Sweden.
authors.forename: Martin K M
authors.initials: MK
authors.lastname: Engqvist
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Florian
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Ina
authors.initials: I
authors.lastname: Krahnert
authors.affiliation: Plant Molecular Physiology and Biotechnology, Institute of Plant Developmental and Molecular Biology, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich-Heine-University, Universitätsstr 1, D-40225, Düsseldorf, Germany.
authors.forename: Veronica G
authors.initials: VG
authors.lastname: Maurino
authors.affiliation: Max-Planck Partner Group, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, 36570-900, Viçosa, Minas Gerais, Brazil.
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Araújo
authors.affiliation: Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
mesh_terms: D000597:Amino Acids, Branched-Chain / Q000378:metabolism / Q000502:physiology*; D017360:Arabidopsis / Q000378:metabolism / Q000502:physiology*; D019069:Cell Respiration / Q000502:physiology; D002952:Citric Acid Cycle / Q000502:physiology; D003681:Dehydration / Q000378:metabolism / Q000503:physiopathology; D010788:Photosynthesis / Q000502:physiology; D060888:Real-Time Polymerase Chain Reaction; D014233:Tricarboxylic Acids / Q000378:metabolism
chemical_list: D000597:Amino Acids, Branched-Chain; D014233:Tricarboxylic Acids
keywords: ETF/ETFQO pathway; branched-chain amino acids; drought; metabolomics; respiration; tricarboxylic acid cycle