Arabidopsis DESPERADO/AtWBC11 Transporter Is Required for Cutin and Wax Secretion

• Published in: Plant physiology (Bethesda) 2007-12, Vol.145 (4), p.1345-1360
• Main Authors: Panikashvili, David, Savaldi-Goldstein, Sigal, Mandel, Tali, Yifhar, Tamar, Franke, Rochus B, Höfer, René, Schreiber, Lukas, Chory, Joanne, Aharoni, Asaph
• Format: Article
• Language: English
• Subjects: Abscisic Acid - physiology; Adaptation, Physiological; Animal cuticle; Arabidopsis - metabolism; Arabidopsis - physiology; Arabidopsis - ultrastructure; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; ATP Binding Cassette Transporter, Sub-Family G; ATP binding cassette transporters; ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Biochemical Processes and Macromolecular Structures; Biological and medical sciences; Epidermal cells; Fatty acids; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, Reporter; Genes. Genome; Leaves; Membrane Lipids - biosynthesis; Molecular and cellular biology; Molecular genetics; Mutation; Phenotype; Phenotypes; Plant cuticle; Plant Epidermis - metabolism; Plant Epidermis - ultrastructure; Plant Roots - metabolism; Plants; Salinity; Stems; Waxes; Waxes - metabolism
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.107.105676

The cuticle fulfills multiple roles in the plant life cycle, including protection from environmental stresses and the regulation of organ fusion. It is largely composed of cutin, which consists of C₁₆₋₁₈ fatty acids. While cutin composition and biosynthesis have been studied, the export of cutin monomers out of the epidermis has remained elusive. Here, we show that DESPERADO (AtWBC11) (abbreviated DSO), encoding a plasma membrane-localized ATP-binding cassette transporter, is required for cutin transport to the extracellular matrix. The dso mutant exhibits an array of surface defects suggesting an abnormally functioning cuticle. This was accompanied by dramatic alterations in the levels of cutin monomers. Moreover, electron microscopy revealed unusual lipidic cytoplasmatic inclusions in epidermal cells, disappearance of the cuticle in postgenital fusion areas, and altered morphology of trichomes and pavement cells. We also found that DSO is induced by salt, abscisic acid, and wounding stresses and its loss of function results in plants that are highly susceptible to salt and display reduced root branching. Thus, DSO is not only essential for developmental plasticity but also plays a vital role in stress responses.