Xyloglucan endotransglycosylases: diversity of genes, enzymes and potential wall-modifying functions

Plant cells are enclosed by walls that define the shapes and sizes of cells and mediate cell-to-cell contact. The dynamics of plant growth, morphogenesis and differentiation require concomitant modifications of the walls. A class of enzymes known as xyloglucan endotransglycosylases have the potential to enzymatically modify wall components, but although their biochemical activity has been defined, the physiological roles of xyloglucan endotransglycosylases remain undefined. Xyloglucan endotransglycosylases are encoded by large gene families, and in an attempt to clarify their physiological role, the diverse regulation of the genes and properties of the proteins are being determined.