Suberin research in the genomics era—New interest for an old polymer

• Published in: Plant science (Limerick) Vol. 180; no. 3; pp. 399 - 413
• Main Authors: Ranathunge, Kosala, Schreiber, Lukas, Franke, Rochus
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier Ireland Ltd 01.03.2011; [Ireland]: Elsevier Science Ireland Ltd; Elsevier
• Subjects: alcohols; Apoplastic barriers; Arabidopsis; Arabidopsis - genetics; Arabidopsis - metabolism; Biological and medical sciences; biopolymers; biosynthesis; Cell Wall; Cell Wall - chemistry; Cell Wall - physiology; cell walls; chemistry; Endodermis; fatty acids; ferulic acid; Fundamental and applied biological sciences. Psychology; genetics; Genomics; Lipids; Lipids - chemistry; Lipids - genetics; Lipids - physiology; metabolism; Molecular Biology; nutrients; oxygen; pathogens; Periderm; physiology; Plant Roots; Plant Stems; Plants; Plants - genetics; Plants - metabolism; Polyester; Polymers; Rhizodermis; roots; Suberin; suberization; wetland plants; wound periderm; α,ω-DCA; Polyester; MS; ω-OHA; Apoplastic barriers; FAE; ROL; OPR; PPP; Suberin; KCS; Periderm; Rhizodermis; GC; GPAT; TEM; KCNS; Endodermis; Root; Genomics; Ester polymer; Plant biology; Epidermis; Polymer; Barrier; Apoplast; Endoderm
• DOI: 10.1016/j.plantsci.2010.11.003
• ISSN: 0168-9452; 1873-2259

▶ The first genes involved in suberin formation have been identified. ▶ Mutant analysis challenges models about biosynthesis and structure of suberin. ▶ Genetic evidence has established a crucial role for suberin in controlling water and ion transport. Suberin is an apoplastic biopolymer with tissue-specific deposition in the cell walls of the endo- and exodermis of roots, of periderms including wound periderm and other border tissues. Suberised cell walls contain both polyaliphatic and polyaromatic domains which are supposedly cross-linked. The predominant aliphatic components are ω-hydroxyacids, α,ω-diacids, fatty acids and primary alcohols, whereas hydroxycinnamic acids, especially ferulic acid, are the main components of the polyaromatic domain. Although the monomeric composition of suberin has been known for decades, its biosynthesis and deposition has mainly been a subject of speculation. Only recently, significant progress elucidating suberin biosynthesis has been achieved using molecular genetic approaches, especially in the model species Arabidopsis. In parallel, the long-standing hypothesis that suberin functions as an apoplastic barrier has been corroborated by sophisticated, quantitative physiological studies in the past decade. These studies demonstrated that suberised cell walls could act as barriers, minimising the movement of water and nutrients, restricting pathogen invasion and impeding toxic gas diffusion. In addition, suberised cell walls provide a barrier to radial oxygen loss from roots to the anaerobic root substrate in wetland plants. The recent onset of multidisciplinary approaches combining genetic, analytical and physiological studies has begun to deliver further insights into the physiological importance of suberin depositions in plants.