Cells produced by the root and shoot tip meristems become the secondaryprimary tissues of the plant body.

Cells produced by the root and shoot tip meristems become the primary tissues of the plant body. 
The elongation of the root and stem forms the primary plant body. This primary plan body is composed of primary tissues. The primary plant body includes the young, soft shoots and roots of a tree or shrub, or the entire plant body in some herbaceous plants.