Fig. 4.

Parameters of the graviproprioception (GP) model and the sine-law model estimated for the hypocotyls in Figs. 2, 3 at each observed time point after turning through 90°. a, b Parameters estimated for $\mathit{\partial }C/\mathit{\partial }t$ from hypocotyls with downward (a) and upward (b)-facing cotyledons, respectively. In the top panels, for the GP model, β = black circle and γ = black triangle; for the sine-law model, β = red circle. Solid symbols mean that their values are not significantly different from 0 (P > 0.05). Thick horizontal lines indicate the time period when autostraightening occurred in Figs. 2e, 3e. In the middle and bottom panels, the Akaike information criterion (AIC) and the adjusted R² are shown, respectively, for the GP model (black) and the sine-law model (red). Parameters were estimated for the apical portions of hypocotyls of which s was longer than 1.14 mm for a, and 1.33 mm for b. Some of the values of β and γ at t < 0.7 h fall outside of the area of these plots, and thus are shown in Fig. S6. c, d Parameters estimated for LRL from the same hypocotyls as in a and b, respectively. LRL was modeled after the GP and the sine-law models, and parameters are shown as in (a, b). For more details, see legend to a and b. Some of the values of β and γ at t < 0.9 h fall outside of the area of these plots, and thus are shown in Fig. S7. e, f A time–space map of β for the sine-law model for LRL from the same hypocotyls as in a and b, respectively. Segments of hypocotyls which were longer than 0.76 mm, and in which their LRL followed the sine-law model with R² > 0.95, are shown as a t‒s map (see Fig. S8 for an example). Such segments are colored according to β as shown in the color key, which is common to (e) and (f). These maps are superimposed with contour lines of LRL = −0.48 (red) and 0 (light blue) in (e), and LRL = −0.225 (red) and 0 (light blue) in (f), respectively