Nitrogen Source Dependent Changes in Central Sugar Metabolism Maintain Cell Wall Assembly in Mitochondrial Complex I-Defective frostbite1 and Secondarily Affect Programmed Cell Death

• Published in: International journal of molecular sciences 2018-07, Vol.19 (8), p.2206
• Main Authors: Podgórska, Anna, Ostaszewska-Bugajska, Monika, Tarnowska, Agata, Burian, Maria, Borysiuk, Klaudia, Gardeström, Per, Szal, Bożena
• Format: Article
• Language: English
• Subjects: Ammonium; Apoptosis; Arabidopsis - cytology; Arabidopsis - genetics; Arabidopsis - growth & development; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Cell Death; Cell Wall - genetics; Cell Wall - metabolism; cell wall synthesis; Cell walls; Cellulose; complex I defect; Dismantling; Electron transport chain; frostbite1; Metabolism; Mitochondria; Mitochondria - genetics; Mitochondria - metabolism; mitochondrial mutant; NADH Dehydrogenase - genetics; NADH Dehydrogenase - metabolism; NADH-ubiquinone oxidoreductase; NDUFS4; necrosis; Nitrates; Nitrates - metabolism; Nitrogen; Nitrogen - metabolism; Nutrition; Point Mutation; programmed cell death; Protein turnover; Proteins; Reactive oxygen species; Reactive Oxygen Species - metabolism; sugar signaling; sugar tabolism; Sugars - metabolism; Toxicity
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms19082206

For optimal plant growth, carbon and nitrogen availability needs to be tightly coordinated. Mitochondrial perturbations related to a defect in complex I in the ( ) mutant, carrying a point mutation in the 8-kD Fe-S subunit of NDUFS4 protein, alter aspects of fundamental carbon metabolism, which is manifested as stunted growth. During nitrate nutrition, plants showed a dominant sugar flux toward nitrogen assimilation and energy production, whereas cellulose integration in the cell wall was restricted. However, when cultured on NH₄⁺ as the sole nitrogen source, which typically induces developmental disorders in plants (i.e., the ammonium toxicity syndrome), showed improved growth as compared to NO₃ nourishing. Higher energy availability in plants was correlated with restored cell wall assembly during NH₄⁺ growth. To determine the relationship between mitochondrial complex I disassembly and cell wall-related processes, aspects of cell wall integrity and sugar and reactive oxygen species signaling were analyzed in plants. The responses of plants to NH₄⁺ treatment were consistent with the inhibition of a form of programmed cell death. Resistance of plants to NH₄⁺ toxicity coincided with an absence of necrotic lesion in plant leaves.