β-tubulin affects cellulose microfibril orientation in plant secondary fibre cell walls

Abstract

Cellulose microfibrils are the major structural component of plant secondary cell walls. Their arrangement in plant primary cell walls, and its consequent influence on cell expansion and cellular morphology, is directed by cortical microtubules; cylindrical protein filaments composed of heterodimers of α- and β-tubulin. In secondary cell walls of woody plant stems the orientation of cellulose microfibrils influences the strength and flexibility of wood, providing the physical support that has been instrumental in vascular plant colonization of the troposphere. Here we show that a Eucalyptus grandisβ-tubulin gene (EgrTUB1) is involved in determining the orientation of cellulose microfibrils i..