Simultaneous Overexpression of Three Enzymes of Chloroplast Metabolism Fails to Improve CO ₂ Assimilation or Biomass

Ensuring an adequate food supply amidst a growing global population and climate change challenges, necessitates innovative strategies to enhance crop productivity. Previous studies have demonstrated that the simultaneous stimulation of different photosynthesis-related processes can increase the rate of photosynthetic carbon assimilation and plant biomass. This study evaluates an approach based on modelling aimed at simultaneously increasing photosynthetic and sink capacities in Nicotiana tabacum by overexpressing three key enzymes: Sedoheptulose-1,7-bisphosphatase (SBPase), Fructose-1,6-bisphosphate aldolase (FBP Aldolase), and ADP-glucose pyrophosphorylase (AGPase). Our results showed that this strategy does not significantly improve growth or carbon assimilation in Nicotiana tabacum under the tested conditions. This suggests that while the model informing our work offers a valuable framework, its application may require adjustments based on species and environmental conditions. Future research should explore these genetic modifications in species with larger sink capacities and under a range of growth conditions to fully realize the potential of photosynthetic optimization.