The cuticle is a complex aliphatic polymeric layer connected to the cell wall and covers surfaces of all aerial plant organs. The cuticle prevents nonstomatal water loss, regulates gas exchange, and acts as a barrier against pathogen infection. The cuticle is synthesized by epidermal cells and predominantly consists of an aliphatic polymer matrix (cutin) and intracuticular and epicuticular waxes. Cutin monomers are primarily C 16 and C 18 unsubstituted, v-hydroxy, and a,v-dicarboxylic fatty acids. Phenolics such as ferulate and p-coumarate esters also contribute to a minor extent to the cutin polymer. Here, we present the characterization of a novel acyl-coenzyme A (CoA)-dependent acyl-transferase that is encoded by a gene designated Deficient in Cutin Ferulate (DCF). The DCF protein is responsible for the feruloylation of v-hydroxy fatty acids incorporated into the cutin polymer of aerial Arabidopsis (Arabidopsis thaliana) organs. The enzyme specifically transfers hydroxycinnamic acids using v-hydroxy fatty acids as acyl acceptors and hydroxycinnamoyl-CoAs, preferentially feruloyl-CoA and sinapoyl-CoA, as acyl donors in vitro. Arabidopsis mutant lines carrying DCF loss-of-function alleles are devoid of rosette leaf cutin ferulate and exhibit a 50% reduction in ferulic acid content in stem insoluble residues. DCF is specifically expressed in the epidermis throughout all green Arabidopsis organs. The DCF protein localizes to the cytosol, suggesting that the feruloylation of cutin monomers takes place in the cytoplasm.The cuticle, a complex polymeric layer connected to the cell wall of epidermal cells, covers the surfaces of all aerial plant organs. The cuticle prevents nonstomatal water loss, regulates gas exchange, acts as a barrier against pathogen infection, and prevents organ fusions (Lolle et al., 1998;Sieber et al., 2000). The plant cuticle is synthesized by epidermal cells and predominantly consists of a lipophilic polymer matrix (cutin) and intracuticular and epicuticular waxes. Cutin monomers are primarily aliphatic C 16 and C 18 unsubstituted, v-hydroxy, and a,v-dicarboxylic fatty acids. Polyhydroxy fatty acids, fatty alcohols, phenolic acids such as ferulic and p-coumaric acid, and glycerol may also contribute to cutin composition in different plant species (Baker and Martin, 1963;Kolattukudy, 1980;Pollard et al., 2008;Samuels et al., 2008;Schreiber, 2010).In Arabidopsis (Arabidopsis thaliana), several enzymes have been identified to be involved in cutin monomer synthesis and polymerization processes, such as glycerol-3-phosphate acyl-transferases 4 and 8 (Li et al., 2007), Bodyguard (Kurdyukov et al., 2006), and Defective in Cuticular Ridges (DCR), a BAHD family enzyme involved in cutin polyester synthesis in Arabidopsis roots, flowers, and seeds. DCR mutant lines are characterized by an almost complete lack of 9 (10),16-dihydroxy-hexadecanoic acid, a major component of the flower cutin polymer, accompanied by several cuticle-associated phenotypic alterations in response to abiotic stresses (e.g. impa...

Isoflavonoids are a class of phenylpropanoids made by legumes, and consumption of dietary isoflavonoids confers benefits to human health. Our aim is to understand the regulation of isoflavonoid biosynthesis. Many studies have shown the importance of transcription factors in regulating the transcription of one or more genes encoding enzymes in phenylpropanoid metabolism. In this study, we coupled bioinformatics and coexpression analysis to identify candidate genes encoding transcription factors involved in regulating isoflavonoid biosynthesis in Lotus (Lotus japonicus). Genes encoding proteins belonging to 39 of the main transcription factor families were examined by microarray analysis of RNA from leaf tissue that had been elicited with glutathione. Phylogenetic analyses of each transcription factor family were used to identify subgroups of proteins that were specific to L. japonicus or closely related to known regulators of the phenylpropanoid pathway in other species. R2R3MYB subgroup 2 genes showed increased expression after treatment with glutathione. One member of this subgroup, LjMYB14, was constitutively overexpressed in L. japonicus and induced the expression of at least 12 genes that encoded enzymes in the general phenylpropanoid and isoflavonoid pathways. A distinct set of six R2R3MYB subgroup 2-like genes was identified. We suggest that these subgroup 2 sister group proteins and those belonging to the main subgroup 2 have roles in inducing isoflavonoid biosynthesis. The induction of isoflavonoid production in L. japonicus also involves the coordinated down-regulation of competing biosynthetic pathways by changing the expression of other transcription factors.