Cell wall composition in relation to photosynthesis across land plants’ phylogeny: crops as outliers

In the present study, we combine published and novel data on cell wall composition and photosynthesis limitations, including data for all the major land plant’s phylogenetic groups. We provide novel evidence on the importance of cell wall composition in determining mesophyll conductance to CO₂ diffusion (g_m) across land plants’ phylogeny. We address the hypothesis that the pectin fraction of total major cell wall compounds is positively related to g_m and, consequently, to photosynthesis, when pooling species from across the entire phylogeny.