Ans. 'Cell walls of plants would no longer maintain their rigid form.'
Cellulose is the main component of plant cell walls, that provides rigidity to the plant cells. It is made up of glucose units and is insoluble in water, due to its high molecular weight and complex crystalline structure.
The water insoluble nature of cellulose make it an important component of tough cell walls of plant cells and makes the plant leaves, branches, and stems so strong.
Thus, if cellulose was water soluble, cell walls of the plant cells would no longer able to maintain their rigid form.