title: Relationship of growth cessation with the formation of diferulate cross-links and p-coumaroylated lignins in tall fescue leaf blades.
abstract: We examined relationships among cell wall feruloylation, diferulate cross-linking, p-coumarate deposition, and apoplastic peroxidase (EC 1.11.1.7) activity with changes in the elongation rate of leaf blades of slow and rapid elongating genotypes of tall fescue ( Festuca arundinacea Schreb.). Growth was not directly influenced by ferulic acid deposition but leaf elongation decelerated as 8-5-, 8- O-4-, 8-8-, and 5-5-coupled diferulic acids accumulated in cell walls. Growth rapidly slowed and stopped with the deposition of p-coumarate, which is primarily associated with lignification in grass cell walls. Accretion of ferulate, diferulates and p-coumarate continued after growth ended, into the later stages of secondary wall formation. The concentration of 8-coupled diferulates dwarfed that of the more commonly measured 5-5-coupled isomer, suggesting that the latter dimer is a poor indicator of diferulate cross-linking in cell walls. Further work is required to clearly demonstrate the role of diferulate cross-linking and p-coumaroylated lignins in the cessation of leaf growth in grasses.
authors.affiliation: Department of Plants, Soils, and Biometeorology, Utah State University, Logan 84322-4820, USA. jenmac@cc.usu.edu
authors.forename: Jennifer W
authors.initials: JW
authors.lastname: MacAdam
authors.forename: John H
authors.initials: JH
authors.lastname: Grabber
mesh_terms: D002473:Cell Wall / Q000201:enzymology / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism*; D031751:Festuca / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D005838:Genotype; D008031:Lignin / Q000378:metabolism*; D009195:Peroxidase / Q000378:metabolism; D019441:Plant Epidermis / Q000254:growth & development / Q000378:metabolism; D018515:Plant Leaves / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism; D011422:Propionates
chemical_list: D003373:Coumaric Acids; D011422:Propionates; D008031:Lignin; C004999:ferulic acid; D009195:Peroxidase; C495469:p-coumaric acid