Tracking the Orchestration of the Tricarboxylic Acid Pathway in Plants, 80 Years After the Discovery of the Krebs Cycle

Plant respiratory metabolism and its associated CO2 efflux rate has been extensively studied in the past decades, and there is now a considerable body of data showing that respiration can be influenced by multiple factors, including temperature, gaseous conditions, and nutrient availability. However, plant leaf respiratory CO2 efflux cannot be predicted or modeled simply from accessible parameters such as N elemental content, CO2 mole fraction or photosynthesis rate. It is likely that this enduring difficulty stems from the tricarboxylic acid pathway (TCAP) being at the crossroad of multiple metabolisms and thus influenced by simultaneous and potentially opposite forces. In this chapter, metabolic interactions between the TCAP and other pathways are illustrated with recent findings, so as to establish a list of key actors that should be considered in future investigations.