Spatial and temporal specifications of Actin11 and EF1β transcript density. Actin11 (A) and EF1β (B) transcript density (a.u. mm-1) in 1 mm-long segments of the primary root. Mean ± standard error of mean (SEM; n = 3). The black line corresponds to the cubic spline interpolation of the means. Actin11 (C) and EF1β (D) transcript density as a function of time in an element moving across the growth zone. Mean ± SEM (n = 3).