title: Enzymes and other agents that enhance cell wall extensibility.
abstract: Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.
authors.affiliation: Department of Biology, Pennsylvania State University, University Park 16802, USA. dcosgrove@PSU.EDU
authors.forename: D J
authors.initials: DJ
authors.lastname: Cosgrove
mesh_terms: D002473:Cell Wall / Q000201:enzymology; D002480:Cellulase / Q000378:metabolism*; D002482:Cellulose / Q000378:metabolism; D016695:Glycosyltransferases / Q000378:metabolism*; D008954:Models, Biological; D059828:Plant Cells; D063245:Plant Development; D018521:Plant Physiological Phenomena; D010940:Plant Proteins / Q000378:metabolism*; D010944:Plants / Q000201:enzymology* / Q000378:metabolism; D011134:Polysaccharides / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D011134:Polysaccharides; C095825:expansin protein, plant; D002482:Cellulose; D016695:Glycosyltransferases; C073693:xyloglucan endotransglycosylase; D002480:Cellulase