Alternative Oxidase: A Mitochondrial Respiratory Pathway to Maintain Metabolic and Signaling Homeostasis during Abiotic and Biotic Stress in Plants

Alternative oxidase (AOX) is a non-energy conserving terminal oxidase in the plant mitochondrial electron transport chain. While respiratory carbon oxidation pathways, electron transport, and ATP turnover are tightly coupled processes, AOX provides a means to relax this coupling, thus providing a degree of metabolic homeostasis to carbon and energy metabolism. Beside their role in primary metabolism, plant mitochondria also act as "signaling organelles", able to influence processes such as nuclear gene expression. AOX activity can control the level of potential mitochondrial signaling molecules such as superoxide, nitric oxide and important redox couples. In this way, AOX also provides a degree of signaling…

• UO
  University of Toronto
• NS
  Natural Sciences and Engineering Research Council of Canada
• UO
  University of Toronto Scarborough