Rubisco: Physiology in Vivo

Abstract

A broad overview of the physiology and biochemistry of Rubisco is presented with a comparison of information obtained in vitro and in vivo. First a brief background to kinetic properties of Rubisco is given and Rubisco’s influence on photosynthetic metabolism is reviewed for C3, C4, CAM and C3-C4 species. The effect of environmental variables such as light and CO2 are considered for both short and longer term effects on the activity and abundance of Rubisco protein. Over the past few years experiments with transgenic plants with antisense RNA constructs to Rubisco, Rubisco activase and several of the PCR cycle enzymes have added new insights into Rubisco physiology. For example, transgenic tobacco with reduced amount of Rubisco has allowed the identification of environmental conditions where Rubisco exerts maximal control on photosynthesis. These plants have also been used to determine Rubisco kinetic constants in vivo. Transgenic plants with reduced amounts of Rubisco activase have been used to elucidate the role of activase in vivo.