Cell wall pits allow movement of water between xylem vessels and are formed via Rho-GTPase mediated signaling that leads to local microtubule disassembly. Here, Sugiyama et al. show that an additional Rho-GTPase pathway controls cell wall deposition and actin dynamics to form pit boundaries.

The interactions of lignin with polysaccharides in plant secondary cell walls are not well understood. Here the authors employ solid-state NMR measurements to analyse intact stems of maize, Arabidopsis, switchgrass and rice and observe that lignin self-aggregates and forms highly hydrophobic microdomains that make extensive surface contacts to xylan.

A distinct feature of pollen gains is their resistant outer wall, called the exine, which is mainly composed of sporopollenin, the toughest biopolymer known to date despite an unknown detailed structure. Now, a structural model of pine sporopollenin is revealed by the application of new degradation chemistry and solid-state NMR spectroscopy.

Despite their importance in plant development and defence the properties of (1,3)-β-glucan remain largely unknown. Here, the authors find that addition of (1,3)-β-glucans increases the flexibility of cellulose and its resilience to high strain, an effect originating in molecular level interactions.

Plant primary and secondary cell walls have distinct features and functions. Now, scientists have successfully replaced the secondary cell wall in Arabidopsis xylem fibres with a thick primary cell wall by specifically overexpressing AP2/ERF transcription factors.