title: Action of xyloglucan hydrolase within the native cell wall architecture and its effect on cell wall extensibility in azuki bean epicotyls.
abstract: Xyloglucan hydrolase (XGH) has recently been purified from the cell wall of azuki bean (Vigna angularis Ohwi et Ohashi) epicotyls as a new type of xyloglucan-degrading enzyme [Tabuchi et al. (2001) Plant Cell Physiol. 42: 154]. In the present study, the effects of XGH on the mechanical properties of the cell wall and on the level and the molecular size of xyloglucans within the native wall architecture were examined in azuki bean epicotyls. When the epidermal tissue strips from the growing regions of azuki bean epicotyls were incubated with XGH, the mechanical extensibility of the cell wall dramatically increased. XGH exogenously applied to cell wall materials (homogenates) or epidermal tissue strips decreased the amount of xyloglucans via the solubilization of the polysaccharides. Also, XGH substantially decreased the molecular mass of xyloglucans in both materials. These results indicate that XGH is capable of hydrolyzing xyloglucans within the native cell wall architecture and thereby increasing the cell wall extensibility in azuki bean epicotyls.
authors.affiliation: Department of Biological Sciences, Graduate School of Science, Osaka City University, Sugimoto, Sumiyoshi-ku, Osaka, 558-8585 Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Kaku
authors.forename: Akira
authors.initials: A
authors.lastname: Tabuchi
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Wakabayashi
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Kamisaka
authors.forename: Takayuki
authors.initials: T
authors.lastname: Hoson
mesh_terms: D001696:Biomechanical Phenomena; D002455:Cell Division / Q000502:physiology; D002473:Cell Wall / Q000187:drug effects / Q000378:metabolism*; D002482:Cellulose / Q000302:isolation & purification / Q000378:metabolism; D007887:Fabaceae / Q000201:enzymology* / Q000254:growth & development; D005936:Glucans; D006026:Glycoside Hydrolases / Q000008:administration & dosage / Q000378:metabolism*; D018519:Meristem / Q000254:growth & development / Q000378:metabolism; D010368:Pectins / Q000302:isolation & purification / Q000378:metabolism; D019441:Plant Epidermis / Q000378:metabolism; D018547:Plant Stems / Q000201:enzymology* / Q000254:growth & development; D011134:Polysaccharides / Q000302:isolation & purification / Q000378:metabolism; D014990:Xylans
chemical_list: D005936:Glucans; D011134:Polysaccharides; D014990:Xylans; C029353:xyloglucan; C007916:hemicellulose; D010368:Pectins; D002482:Cellulose; D006026:Glycoside Hydrolases; C046206:oligoxyloglucan hydrolase