Caffeic acid: O-methyltransferases and the biosynthesis of ferulic acid in primary cell walls of wheat seedlings

• Published in: Phytochemistry (Oxford) Vol. 41; no. 6; pp. 1507 - 1510
• Main Authors: Thi Bach Tuyet Lam, Iiyama, Kenji, Stone, Bruce A.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 01.04.1996; Elsevier
• Subjects: Biochemistry & Molecular Biology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Life Sciences & Biomedicine; Metabolism; Metabolism. Physicochemical requirements; Plant physiology and development; Plant Sciences; Science & Technology; ferulic acid; coniferyl alcohol dehydrogenase; Gramineae; O-methyltransferase; 5-hydroxyferulic acid; lignin; p-coumaric acid; caffeic acid; Triticum aestivum; ferulic acid ester-ether bridges; PHENOLIC-ACIDS; INTERNODES; POLYSACCHARIDES; PURIFICATION; ESTERS; Lignin; Monocotyledones; Enzyme; Transferases; Biosynthesis; Cinnamic acid(4-hydroxy 3-methoxy); Cereal crop; Cell wall; Caffeate O-methyltransferase; Methyltransferases; Enzymatic activity; Substrate specificity; Angiospermae; Plantlet; Spermatophyta; Developmental stage
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/0031-9422(95)00810-1

The activity of O-methyltransferases (OMT) in tissues of wheat and the changes in their specificity for hydroxycinnamic acid substrates was followed during seedling development. In the early stages of development, prior to lignin deposition, the OMT showed a preference for caffeic acid as a substrate. This acitivity peaked at day 3. Later, after lignin deposition had begun, the activities of OMT and cinnamyl aldehyde dehydrogenase increased continuously and the OMT had a preference for 5-hydroxyferulic acid. It is suggested that the “early” OMT may be involved in the synthesis of ferulic acid destined for esterification of cell wall arabinoxylans whereas, the “late” OMT may be involved with the synthesis of ferulic and sinapic acids which are converted to the monolignol building blocks of lignin.