Figure 5.
The gravity response depends on the location of applied NPA. NPA was continuously applied to roots for the entire experiment at the root tip or root-shoot junction, or by addition to the agar plate on which the plant was grown. During the first 24 h, the growth was vertical, then the plants were reoriented by 90°, and the angle of curvature was determined after an additional 24 h of growth. The average and sd of 10 roots are reported. □, Global application; ○, root-shoot junction application; ▴, root tip application.