Review: Photorespiration is the solution, not the problem

Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) is one of a kind, simultaneously recognized as one of the most abundant and important enzymes, and also widely characterized as flawed because it uses both O₂ and CO₂ as substrates, leading to both carboxylation and oxygenation of ribulose bisphosphate. When CO₂ is used as a substrate, the carbon is fixed and converted to sugars, but when O₂ is the substrate the product, 2-phosphoglycolate, must be removed through the photorespiratory pathway (consuming ATP) to avoid inhibiting rubisco. Several strategies to improve photosynthesis have bene explored, many of which suppress photorespiration, but, as discussed in a Humboldt Revew by Bauwe and further highlighted in a commentary by Brocano et al., photorespiration is not itself the problem but rather the solution. The Bauwe review is encyclopedic and essential to those who work in the field, whereas the Brocano et al. article beautifully distills the essences for the rest of us. (Summary by Mary Williams @PlantTeaching) J. Plant Physiol. 10.1016/j.jplph.2022.153899 and 10.1016/j.jplph.2023.153928