title: Cellulose metabolism in plants.
abstract: Many bacterial genomes contain a cellulose synthase operon together with a cellulase gene, indicating that cellulase is required for cellulose biosynthesis. In higher plants, there is evidence that cell growth is enhanced by the overexpression of cellulase and prevented by its suppression. Cellulase overexpression could modify cell walls not only by trimming off the paracrystalline sites of cellulose microfibrils, but also by releasing xyloglucan tethers between the microfibrils. Mutants for membrane-anchored cellulase (Korrigan) also show a typical phenotype of prevention of cellulose biosynthesis in tissues. All plant cellulases belong to family 9, which endohydrolyzes cellulose, but are not strong enough to cause the bulk degradation of cellulose microfibrils in a plant body. It is hypothesized that cellulase participates primarily in repairing or arranging cellulose microfibrils during cellulose biosynthesis in plants. A scheme for the roles of plant cellulose and cellulases is proposed.
authors.affiliation: Research Institute for Sustainable Humanosphere, Kyoto University, Gokasho Uji 611-0011, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Hayashi
authors.forename: Kouki
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Park
authors.forename: Teruko
authors.initials: T
authors.lastname: Konishi
authors.forename: Kei'ichi
authors.initials: K
authors.lastname: Baba
mesh_terms: D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D002480:Cellulase / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D044602:Cellulases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D002482:Cellulose / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D015870:Gene Expression; D005936:Glucans / Q000096:biosynthesis / Q000502:physiology; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010641:Phenotype; D010944:Plants / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism*; D014990:Xylans / Q000096:biosynthesis
chemical_list: D005936:Glucans; D014990:Xylans; C029353:xyloglucan; D002482:Cellulose; D005964:Glucosyltransferases; C478648:cellulose synthase; D044602:Cellulases; D002480:Cellulase