Suberization — the second life of an endodermal cell. (December 2015)

• Record Type: Journal Article
• Authors: Andersen, Tonni Grube; Barberon, Marie; Geldner, Niko
• Is Part Of: Current opinion in plant biology. Volume 28(2015)
• Page Start: 9
• Page End: 15
• Publication Date: 2015-12
• Subjects: Plant molecular biology -- Periodicals; 571.205
• DOI: 10.1016/j.pbi.2015.08.004
• Languages: English
• ISSNs: 1369-5266

Abstract

Highlights: The root endodermis undergoes two states of differentiation, Casparian strip formation and suberization. Suberin is a hydrophobic secondary cell wall with a function distinct from Casparian strips. Passage cells remain unsuberized and are thought to be entry points in mature endodermis. Endodermal suberization regulates transport of water and nutrients and responds to (a)biotic stresses. Abstract : The endodermis is the innermost cortical cell layer that surrounds the central vasculature and deposits an apoplastic diffusion barrier known as the Casparian strip. Although discovered 150 years ago, the underlying mechanisms responsible for formation of the Casparian strips have only recently been investigated. However, the fate of the endodermal cell goes further than formation of Casparian strips as they undergo a second level of differentiation, defined by deposition of suberin as a secondary cell wall. The presence and function of endodermal suberin in root barriers has remained enigmatic, as its role in barrier formation is not clear, especially in respect to the already existing Casparian strips. In this review, we present recent advances in the understanding of suberin synthesis, transport to the secondary cell wall, developmental features and functions. We focus on some of the major unknown questions revolving the function of endodermal suberin, which we now have the means to investigate. We further provide thoughts on how this knowledge might expand our current models on the developmental and physiological adaptation of root in response to the environment.