Dirigent domain-containing protein is part of the machinery required for formation of the lignin-based Casparian strip in the root

• DOI: 10.1073/pnas.1308412110
• Publication Date: 2013-08-13T01:53:00Z
• Authors: Prashant S. Hosmani; Takehiro Kamiya; John Danku; Sadaf Naseer; Niko Geldner; Mary Lou Guerinot; David E. Salt
• Keywords: Root (linguistics)

The endodermis acts as a "second skin" in plant roots by providing the cellular control necessary for selective entry of water and solutes into vascular system. To enable such control, Casparian strips span cell wall adjacent endodermal cells to form tight junction that blocks extracellular diffusion across endodermis. This is composed lignin polymerized oxidative coupling monolignols through action NADPH oxidase peroxidases. strip domain proteins (CASPs) correctly position this biosynthetic machinery forming protein scaffold plasma membrane at site where forms. Here, we show dirigent-domain containing protein, enhanced suberin1 (ESB1), part machinery, playing an essential role correct formation strips. ESB1 localized CASP-dependent manner, absence ESB1, disordered defective are formed. In addition, loss disrupts localization CASP1 casparian domain, suggesting reciprocal requirement both CASPs domain.