The ArabidopsisDESPERADO/AtWBC11Transporter Is Required for Cutin and Wax Secretion

Abstract

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 C 16-18 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.

Two ATP Binding Cassette G (ABCG) Transporters, OsABCG26 and OsABCG15, Collaboratively Regulate Rice Male Reproduction

“…The results indicated that, instead of an overexpression, we obtained cosuppression in the transgenic plants. This has been reported previously for AtABCG11, where overexpression of this gene resulted in a cosuppression (Panikashvili et al, 2007(Panikashvili et al, , 2010.…”

“…Some plant ABCG proteins have been reported to contribute to the synthesis of extracellular barriers. In Arabidopsis, ABCG11 (Cuticular Defect and Organ Fusion1/DESPERADO/White-Brown Complex11; Bird et al, 2007;Panikashvili et al, 2007Panikashvili et al, , 2010, ABCG12 (Eceriferum5/WBC12; Pighin et al, 2004), ABCG13 (Panikashvili et al, 2010), ABCG29 (Alejandro et al, 2012), ABCG32 (Bessire et al, 2011), and ABCG26 (WBC27; Xu et al, 2010;Quilichini et al, 2010Quilichini et al, , 2014Choi et al, 2011;Dou et al, 2011) have been shown to be involved in transport of lipidic compounds. Notably, it has been reported that these ABCG proteins have a broad substrates spectrum (for example, ABCG11 transports both cutin and wax monomers, and ABCG13 and ABCG32 mainly transport cutin monomers, whereas ABCG12 mainly transports wax precursors, and ABCG29 mainly transports monolignol).…”

“…Cutin is a polyester insoluble in organic solvents consisting mainly of fatty acid oxygenated derivatives with a chain length of 16 and 18 carbons, whereas cuticular wax is a complex mixture of very long-chain fatty acid derivatives, terpenoids, and phenolic components (Nawrath, 2002(Nawrath, , 2006. In plant vegetative organs, such as stem and leaf, it is believed that cuticular lipid biosynthesis occurs exclusively within epidermal cells from which lipidic molecules are transported to the organ surface by ATP binding cassette G (ABCG) transporters and lipid transport proteins (LTPs; Sieber et al, 2000;Nawrath, 2002;Pighin et al, 2004;Bird et al, 2007;Panikashvili et al, 2007;Debono et al, 2009). However, biosynthesis and transport of cuticular lipids in reproductive organs remain largely unknown.…”

Rice TUTOU1 Encodes a Suppressor of cAMP Receptor-Like Protein That Is Important for Actin Organization and Panicle Development

“…Cuticles, the hydrophobic, waxy structures produced by the epidermal cells in most land plants, play an important role in plant development and in the tolerance to environmental stresses. The constituents of the cuticle include fatty acids, esters, alcohols, aldehydes, ketones, and alkanes (Kunst and Samuels, 2003;Panikashvili et al, 2007). Defects in fatty acid metabolism or transport can also cause anther degeneration.…”

Highlights of recent progress in plant lipid research

“…Panikasvili and Aharoni (O4) showed the involvement of an ABC transporter, and presented their first results of an exhaustive study concerning ABC transporters [40].…”