hydroxycinnamoyltransferase responsible for synthesizing suberin aromatics in Arabidopsis

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 106; no. 44; pp. 18855 - 18860
• Main Authors: Gou, Jin-Ying, Yu, Xiao-Hong, Liu, Chang-Jun
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 03.11.2009; National Acad Sciences
• Subjects: Acids; acyl coenzyme A; Acyltransferases - metabolism; ARABIDOPSIS; Arabidopsis - enzymology; Arabidopsis - genetics; Arabidopsis Proteins - metabolism; AROMATICS; BAHD superfamily; BASIC BIOLOGICAL SCIENCES; Biological Sciences; Biopolymers; Biopolymers - biosynthesis; Biosynthesis; CELL WALL; Cell Wall - drug effects; Cell Wall - enzymology; Cell walls; Cells; Coumaric Acids - metabolism; DNA, Bacterial - genetics; Environmental stress; ENZYMES; Escherichia coli; Esters; Fatty acids; Flowers & plants; Gene Expression Regulation, Plant - drug effects; GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE; GENES; Genes, Plant; Germination - drug effects; Hydrocarbons, Aromatic - metabolism; hydroxycinnamoyltransferase; IN VITRO; KINETICS; Lipids - biosynthesis; Molecular Sequence Data; MONOMERS; Mutagenesis, Insertional - drug effects; MUTANTS; Mutation - genetics; NUTRIENTS; PERMEABILITY; Permeability - drug effects; phenolic compounds; Phenols; Plant roots; Plant Roots - drug effects; Plant Roots - enzymology; Plant tissues; Plants; plants (botany); POLYESTERS; POLYMERS; Recombinant Proteins - metabolism; roots; salt stress; Seedlings; SEEDS; Seeds - drug effects; Seeds - enzymology; SENSITIVITY; Sodium Chloride - pharmacology; Stress, Physiological - drug effects; STRESSES; suberin; TRANSPORT; wall-bound phenolics; WATER
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.0905555106

Suberin, a polyester polymer in the cell wall of terrestrial plants, controls the transport of water and nutrients and protects plant from pathogenic infections and environmental stresses. Structurally, suberin consists of aliphatic and aromatic domains; p-hydroxycinnamates, such as ferulate, p-coumarate, and/or sinapate, are the major phenolic constituents of the latter. By analyzing the "wall-bound" phenolics of mutant lines of Arabidopsis deficient in a family of acyl-CoA dependent acyltransferase (BAHD) genes, we discovered that the formation of aromatic suberin in Arabidopsis, primarily in seed and root tissues, depends on a member of the BAHD superfamily of enzymes encoded by At5g41040. This enzyme exhibits an ω-hydroxyacid hydroxycinnamoyltransferase activity with an in vitro kinetic preference for feruloyl-CoA and 16-hydroxypalmitic acid. Knocking down or knocking out the At5g41040 gene in Arabidopsis reduces specifically the quantity of ferulate in suberin, but does not affect the accumulation of p-coumarate or sinapate. The loss of the suberin phenolic differentially affects the aliphatic monomer loads and alters the permeability and sensitivity of seeds and roots to salt stress. This highlights the importance of suberin aromatics in the polymer's function.