ABSTRACT
The C3 cycle is the primary biochemical pathway for fixation of atmospheric CO2 in over 85% of plants, including the major crop species. This pathway is autocatalytic involving 11 enzymes catalysing 13 reactions and provides carbon compounds directly for the synthesis of isoprenoids, sucrose, starch, phenylpropanoids, thiamine and nucleotides. One focus of research on the C3 cycle has been to identify bottlenecks to provide strategies for improving crop yield. There have been one or two notable successes from this work, mainly in model species and in controlled environment conditions. Given that the C3 cycle is highly conserved, it is reasonable to predict that lessons learned from model plants will be transferable to crops. We provide an update on the current understanding of the biochemistry, regulation and limitations of the C3 cycle, and future questions to be addressed to enable improvement of the cycle to boost crop yields.
