A Year at the Forefront of Engineering Photosynthesis

Abstract

Multiple proof-of-principle experiments and successful field trials have demonstrated that engineering photosynthesis is a viable strategy for improving crop yields. Advances to engineering technologies have accelerated efforts to improve photosynthesis, generating a large volume of published literature: this Review therefore aims to highlight the most promising results from the period February 2021 to January 2022. Recent research has demonstrated the importance of understanding the impact of changing climates on photosynthesis to ensure that proposed engineering strategies are resilient to climate change. Encouragingly, there have been several reports of strategies that have benefits at temperatures higher than current ambient conditions. There has also been success in engineering synthetic bypass pathways, providing support for the feasibility of a synthetic biology approach. Continued developments in all areas of engineering photosynthesis will be necessary for sustainably securing sufficient crop yields for the future. This article has an associated First Person interview with the first author of the paper.

Climate change challenges, plant science solutions

“…In addition to strategies that aim to improve the efficiency of the C 3 photosynthetic pathway (discussed above, and see Ort et al, 2015 ; Johnson, 2022 ) or to introduce Crassulacean acid metabolism into C 3 plants ( Schiller and Bräutigam, 2021 ), the enhanced efficiency of C 4 photosynthesis provides a potential engineering opportunity for improved yield and resilience against abiotic stresses in C 3 crops. Although the C 4 pathway utilizes two extra ATP molecules per CO 2 fixed than the C 3 pathway, in warm and dry environments where dissolved oxygen conditions are relatively high, these energy costs are offset by those not spent on photorespiration (3.5 ATP per O 2 fixed).…”

Predicting plant Rubisco kinetics from RbcL sequence data using machine learning

“…Improving Rubisco kinetic traits is therefore a target for improving plant carbon uptake and crop yield. One strategy of doing this is screening the natural diversity of Rubisco kinetics and replacing native Rubisco enzymes in plants with catalytically more efficient enzymes ( Ort et al , 2015 ; Hermida-Carrera et al , 2016 ; Orr et al , 2016 ; Sharwood et al , 2016 ; Galmés et al , 2019 ; Orr and Parry, 2020 ; Von Caemmerer, 2020 ; Iqbal et al , 2021 ; Johnson, 2022 ; Lin et al , 2022 ). Although there has been some progress with this strategy, direct replacement of Rubisco in crops is currently challenging, due to both limited capacity to mass-screen Rubisco kinetics, and Rubisco chaperone incompatibilities between distant species ( Kanevski et al , 1999 ; Whitney et al , 2011 , 2015 ; Wilson et al , 2016 , 2018 ; Sharwood, 2017 ; Zhou and Whitney, 2019 ; Gunn et al , 2020 ; Martin-Avila et al , 2020 ).…”