What limits CO2 diffusion inside leaves? Dissecting the diffusion path with Arabidopsis mutants

To improve modelling of global atmospheric carbon dioxide exchange, a mechanistic understanding of carbon dioxide diffusion within photosynthesising leaves is required. We will use mutants to dissect and identify key steps along the diffusion pathway within Arabidopsis leaves. The carbon dioxide permeability of the plasma membrane and chloroplast envelope will be measured directly. These membranes contain abundant protein pores, called aquaporins and by manipulating their abundance we will quantify their role in carbon dioxide diffusion. Because photosynthesis is limited by carbon dioxide diffusion, a better mechanistic understanding has the potential to identify novel targets for plant breeders to use.