Abstract
Xyloglucans are considered to be function as cross-links among cellulose microfibrils in most dicotyledonous cell walls. Xyloglucan endotransglucosylase/hydrolase (XTH) catalyzes cutting and tethering of xyloglucans, thereby mediating construction and reorganization of cell walls. In certain monocotyledonous cell walls, on the other hand, xyloglucans are not considered important in cross-linking cellulose microfibrils. As a matter of fact, however, rice contains 29 XTH genes, which show tissue specific and growth stage dependent expression patterns, suggesting their importance in the rice cell walls. To gain insight into functions of XTHs in rice, we focused on OsXTH19, which was specifically expressed in the dividing/elongating zone of leaf blade and internode. We will report substrate specificity of OsXTH19 using a recombinant protein, and phenotypic traits of transgenic rice lines in which expression levels of OsXTH19 are modified.
