title: HCHL expression in hairy roots of Beta vulgaris yields a high accumulation of p-hydroxybenzoic acid (pHBA) glucose ester, and linkage of pHBA into cell walls.
abstract: As part of a study to explore the potential for new or modified bio-product formation, Beta vulgaris (sugar beet) has been genetically modified to express in root-organ culture a bacterial gene of phenylpropanoid catabolism. The HCHL gene, encoding p-hydroxycinnamoyl-CoA hydratase/lyase, was introduced into B. vulgaris under the control of a CaMV 35S promoter, using Agrobacterium rhizogenes LBA 9402. Hairy root clones expressing the HCHL gene, together with non-expressing clones, were analysed and revealed that one expression-positive clone accumulated the glucose ester of p-hydroxybenzoic acid (pHBA) at about 14% on a dry weight basis. This is the best yield achieved in plant systems so far. Determination of cell-wall components liberated by alkaline hydrolysis confirmed that the ratio of pHBA to ferulic acid was considerably higher in the HCHL-expressing clones, whereas only ferulic acid was detected in a non-expressing clone. The change in cell-wall components also resulted in a decrease in tensile strength in the HCHL-expressing clones.
authors.affiliation: School of Pharmaceutical Sciences, Nagasaki University, 1-14 Bunkyo-machi, Nagasaki, Japan.
authors.forename: Laiq ur
authors.initials: Lu
authors.lastname: Rahman
authors.forename: Hitomi
authors.initials: H
authors.lastname: Kouno
authors.forename: Yuya
authors.initials: Y
authors.lastname: Hashiguchi
authors.forename: Hirobumi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Arjan
authors.initials: A
authors.lastname: Narbad
authors.forename: Adrian
authors.initials: A
authors.lastname: Parr
authors.forename: Nicholas
authors.initials: N
authors.lastname: Walton
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Ikenaga
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Kitamura
mesh_terms: D027461:Beta vulgaris / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D001696:Biomechanical Phenomena; D002473:Cell Wall / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002999:Clone Cells; D004952:Esters / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005947:Glucose / Q000378:metabolism*; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism*; D006868:Hydrolysis; D062385:Hydroxybenzoates / Q000378:metabolism*; D010636:Phenols / Q000378:metabolism; D018517:Plant Roots / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D012995:Solubility; D014170:Transformation, Genetic
chemical_list: D004952:Esters; D062385:Hydroxybenzoates; D010636:Phenols; C119166:4-hydroxycinnamoyl-CoA hydratase-lyase; D006836:Hydro-Lyases; D005947:Glucose