Reviews: The regulation of cellulose biosynthesis in plants, and secondary cell wall biosynthesis

Plant cell walls are complex and somewhat difficult to study, but also idespensible for plants and central to many of the ways that people use plants (from wood to fibers to fuels). Two new articles review diverse aspects of plant cell wall synthesis. Polko and Kieber (Plant Cell 10.1105/tpc.18.00760 $) focus on the regulation of cellulose production and the structure, function and regulation of the cellulose synthase complex. The also review new insights into the intracellular trafficking of cellulose-synthase complexes and its contribution to cell wall sythesis, and the mechanisms behind cell-wall integrity sensing and maintenance. The review by Zhong et al. (New Phytol. 10.1111/nph.15537) focuses on secondary cell wall synthesis. Secondary walls are rigid, form after cell elongation ceases, and strengthen specialized cells including xylem tracheids and vessels. The review highlights insights from genetics and biochemistry into the synthesis of wall components including cellulose, xylan, glucomannan and lignin. Knowledge of cell wall synthesis can be leveraged towards the development of cell walls optimized for specific purposes. (Summary by Mary Williams)