Considering that hydration is such a powerful handle to modify ionic diffusion, using bulkier chemistries rather than simply an acetic anhydride (Fig. ) would be expected to further drive down diffusion. Given the strong interactions between cations and carboxyl groups within plant cells (Figs. 4 5), overexpressing or knocking down the enzymes that catalyze the addition of these groups would be another handle with which to modify ion diffusion within forest products.