Overexpression of carbohydrate binding modules (CBMs) of Cellulomonas fimi glucanase B (CenB) in tobacco modifies cellulose in the cell wall and xylem cell enlargement

摘要

Carbohydrate-binding modules (CBMs) have been shown to alter the structural architecture of plant cell walls. They have the potential of altering the characteristics of fibers in the cell wall. Cellulomonas fimi glucanase B belongs to family 2 CBM and it has been characterized as interacting with cellulose. However, its potential for altering plant cell walls and for modulating plant growth has not been explored. In this study, the expression of CBMs in tobacco plants was evaluated. There were no observable changes in the growth of the transgenic plants compared with the wild type. Histological examinations of transgenic plant stems revealed that xylem cells were bigger than the wild type. Moreover, the cellulose fiber lengths of transgenic plants were longer than the wild type. The results indicated that the family 2 CBM has the potential for modification of cellulose in the cell wall and inducing xylem cell expansion.