A carboxysome‐based CO2 concentrating mechanism for C3 crop chloroplasts: advances and the road ahead

• Published in: The Plant journal : for cell and molecular biology 2024-05, Vol.118 (4), p.940-952
• Main Authors: Nguyen, Nghiem D., Pulsford, Sacha B., Förster, Britta, Rottet, Sarah, Rourke, Loraine, Long, Benedict M., Price, G. Dean
• Format: Article
• Language: English
• Subjects: Bicarbonates; Carbon dioxide; carboxysome; Chloroplasts; CO2‐concentrating mechanism; Crop yield; Crops; Food security; Ribulose-bisphosphate carboxylase; Rubisco; synthetic biology
• ISSN: 0960-7412; 1365-313X; 1365-313X
• DOI: 10.1111/tpj.16667

SUMMARY The introduction of the carboxysome‐based CO2 concentrating mechanism (CCM) into crop plants has been modelled to significantly increase crop yields. This projection serves as motivation for pursuing this strategy to contribute to global food security. The successful implementation of this engineering challenge is reliant upon the transfer of a microcompartment that encapsulates cyanobacterial Rubisco, known as the carboxysome, alongside active bicarbonate transporters. To date, significant progress has been achieved with respect to understanding various aspects of the cyanobacterial CCM, and more recently, different components of the carboxysome have been successfully introduced into plant chloroplasts. In this Perspective piece, we summarise recent findings and offer new research avenues that will accelerate research in this field to ultimately and successfully introduce the carboxysome into crop plants for increased crop yields. Significance Statement The efficacy of the cyanobacterial CO2‐concentrating mechanism (CCM) relies on its ability to concentrate CO2 around the Rubisco enzyme, which is natively encapsulated within a carboxysome. As our understanding of carboxysome biogenesis and functionality grows, there is optimism that this microcompartment and the cyanobacterial CCM as a whole, can contribute to addressing global food security.