title: Influence of mitochondrial genome rearrangement on cucumber leaf carbon and nitrogen metabolism.
abstract: The MSC16 cucumber (Cucumis sativus L.) mitochondrial mutant was used to study the effect of mitochondrial dysfunction and disturbed subcellular redox state on leaf day/night carbon and nitrogen metabolism. We have shown that the mitochondrial dysfunction in MSC16 plants had no effect on photosynthetic CO(2) assimilation, but the concentration of soluble carbohydrates and starch was higher in leaves of MSC16 plants. Impaired mitochondrial respiratory chain activity was associated with the perturbation of mitochondrial TCA cycle manifested, e.g., by lowered decarboxylation rate. Mitochondrial dysfunction in MSC16 plants had different influence on leaf cell metabolism under dark or light conditions. In the dark, when the main mitochondrial function is the energy production, the altered activity of TCA cycle in mutated plants was connected with the accumulation of pyruvate and TCA cycle intermediates (citrate and 2-OG). In the light, when TCA activity is needed for synthesis of carbon skeletons required as the acceptors for NH(4) (+) assimilation, the concentration of pyruvate and TCA intermediates was tightly coupled with nitrate metabolism. Enhanced incorporation of ammonium group into amino acids structures in mutated plants has resulted in decreased concentration of organic acids and accumulation of Glu.
authors.affiliation: Institute of Experimental Plant Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland. szal@biol.uw.edu.pl
authors.forename: Bożena
authors.initials: B
authors.lastname: Szal
authors.forename: Agata
authors.initials: A
authors.lastname: Jastrzębska
authors.forename: Marek
authors.initials: M
authors.lastname: Kulka
authors.forename: Karolina
authors.initials: K
authors.lastname: Leśniak
authors.forename: Anna
authors.initials: A
authors.lastname: Podgórska
authors.forename: Tiit
authors.initials: T
authors.lastname: Pärnik
authors.forename: Hiie
authors.initials: H
authors.lastname: Ivanova
authors.forename: Olav
authors.initials: O
authors.lastname: Keerberg
authors.forename: Per
authors.initials: P
authors.lastname: Gardeström
authors.forename: Anna M
authors.initials: AM
authors.lastname: Rychter
mesh_terms: D015153:Blotting, Western; D002244:Carbon / Q000378:metabolism*; D002952:Citric Acid Cycle; D018553:Cucumis sativus / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000235:genetics*; D009584:Nitrogen / Q000378:metabolism*; D018515:Plant Leaves / Q000378:metabolism*
chemical_list: D004272:DNA, Mitochondrial; D002244:Carbon; D009584:Nitrogen