Hybrid Rubisco with Complete Replacement of Rice Rubisco Small Subunits by Sorghum Counterparts Confers C Plant-like High Catalytic Activity.

Photosynthetic rate at the present atmospheric condition is limited by the CO-fixing enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) because of its extremely low catalytic rate (k) and poor affinity for CO (K) and specificity for CO (S). Rubisco in C plants generally shows higher k than that in C plants. Rubisco consists of eight large subunits and eight small subunits (RbcS).