Why can't collenchyma tissues be found roots?

Plant Histology

Collenchyma tissues are mainly found under the epidermis of young stems and in the large veins of leaves. Thus, they allow rigidity, support and protection to such parts. They are not found in the roots because of the thick cellulose walls, which are, sometimes, impregnated with suberin/lignin. This thick cellulose wall will make the absorption of minerals and water slower and/or impossible that will cause plant death. Also, collenchyma tissues sometimes contain chloroplast, that's why they are found in stems or leaves.