New carbon-fixing cycle helps plants absorb more CO2 and grow larger

Researchers in Taiwan have engineered a novel metabolic pathway, the malyl-CoA-glycerate (McG) cycle, to enhance carbon dioxide absorption and utilization in plants. By integrating this cycle alongside the traditional Calvin-Benson-Bassham cycle in the model plant Arabidopsis thaliana, they significantly increased plant growth, seed yield, and lipid production without raising water consumption. The McG cycle captures carbon more efficiently by incorporating carbon at two steps and produces a two-carbon molecule directly usable for lipid synthesis. This metabolic rewiring led to plants that were two to three times heavier, with more and larger leaves, and dramatically higher triglyceride levels, demonstrating improved biomass and potential for biofuel applications. Despite these promising results, the researchers caution that the findings are preliminary and based on a lab-friendly weed rather than crops or trees. The effects of excess lipid accumulation in larger plants and performance under field conditions remain uncertain. Additionally, the long-term carbon sequestration benefits depend on whether the lipids remain stable