Improving plant photosynthesis by modifying Rubisco and its chaperones

Rubisco (Ribulose-1,5-bisphosphate carboxylase/oxygenase) is one of the most important enzymes for plant photosynthesis, responsible for carbon fixation in the Calvin-Benson-Bassham cycle. Compared to its critical role, Rubisco has low catalytic rate and low specificity for CO2 over O2, greatly limiting the photosynthesis in ambient air. Efforts have been made to enhance Rubisco functional efficiency with genetic engineering towards crop yield growth, including direct modification of Rubisco large subunit (RbcL) and small subunit (RbcS) through point mutation or overexpression, introduction and hybridization of nonnative Rubisco, and indirectly enhancing Rubisco catalysis by increasing the CO2 availability around Rubisco via constructing carbon concentrating mechanisms or manipulating chaperones responsible for Rubisco biogenesis and activation. Although most attempts for increasing plant growth and yield failed, there are inspiring researches suggesting the feasibility of Rubisco engineering for increasing plant photosynthesis. With recent technological breakthroughs for chloroplast genome editing, plant Rubisco assembly in bacterial host and neural network-based model for high accuracy protein three-dimensional structure prediction, Rubisco research is expected to accelerate in a foreseeable future.