Fig. (4) Staining of invertase activity in the parts of the longitudinal sections of the maize root apex. The zone of transition from meristem to elongation is shown. At the bottom – the sections from the basal part of the elongation zone: in the left - the reaction without sucrose in the incubation medium (control), in the right – the reaction with sucrose. Bar – 100 µm. rh – rhizodermis, cor – cortex, en – endodermis, pc – pericycle, mx – metaxylem vessel.