title: Protein degradation - an alternative respiratory substrate for stressed plants.
abstract: In cellular circumstances under which carbohydrates are scarce, plants can metabolize proteins and lipids as alternative respiratory substrates. Respiration of protein is less efficient than that of carbohydrate as assessed by the respiratory quotient; however, under certain adverse conditions, it represents an important alternative energy source for the cell. Significant effort has been invested in understanding the regulation of protein degradation in plants. This has included an investigation of how proteins are targeted to the proteosome, and the processes of senescence and autophagy. Here we review these events with particular reference to amino acid catabolism and its role in supporting the tricarboxylic acid cycle and direct electron supply to the ubiquinone pool of the mitochondrial electron transport chain in plants.
authors.affiliation: Max-Planck Institute for Molecular Plant Physiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany.
authors.forename: Wagner L
authors.initials: WL
authors.lastname: Araújo
authors.forename: Takayuki
authors.initials: T
authors.lastname: Tohge
authors.forename: Kimitsune
authors.initials: K
authors.lastname: Ishizaki
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Leaver
authors.forename: Alisdair R
authors.initials: AR
authors.lastname: Fernie
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001343:Autophagy; D019069:Cell Respiration; D002734:Chlorophyll / Q000378:metabolism; D002952:Citric Acid Cycle; D004579:Electron Transport; D044927:Electron-Transferring Flavoproteins / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008928:Mitochondria / Q000378:metabolism*; D018384:Oxidative Stress; D010940:Plant Proteins / Q000378:metabolism; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D014158:Transcription, Genetic; D054875:Ubiquitination
chemical_list: D000596:Amino Acids; D044927:Electron-Transferring Flavoproteins; D010940:Plant Proteins; D002734:Chlorophyll; D046988:Proteasome Endopeptidase Complex