Figure 1.

Two types of the establishment of root epidermis patterning in monocots. Type I is characterized by an initial symmetric division of a mother cell. In subtype IA, the two identical daughter cells do not show any differences, except for the presence or absence of an RH tube. In subtype IB, the two daughter cells develop into trichoblasts and atrichoblasts through asymmetric expansion, which correlates with a restriction of symplasmic communication between neighboring cells. In type II, the last division is asymmetric. A shorter cell may be located in the shoot-ward (subtype IIA) or root-ward (subtype IIB) position.