The Prospects of Rubisco Improvement

Due to its key role in photosynthesis and apparent inefficiency, Ribulose-1, 5-bisphosphate carboxylase/oxygenase (Rubisco) was a target to numerous attempts to ameliorate its kinetic properties and thereby to enhance the photosynthetic rate. Nevertheless, an improved enzyme was not found. The lack of success results from optimal adaptation of Rubisco to the gaseous environment, wherein it resides and the reciprocal relation between its catalytic turnover and affinity for CO2. Consequently, any improvement in one of these parameters is accompanied with a decrease in the other. Even if an improved Rubisco is found, its influence on the photosynthetic performance will be minor as additional factors limit the photosynthetic rate and since regulatory mechanisms coordinate the carboxylation capacity with the plant need for photo assimilates.