Figure 5.

Profiles of turgor-induced elastic strain (ɛ) along hypocotyls of light-grown sunflower seedlings; position 0 refers to the insertion of the cotyledons. Original data pooled from seven or more plants are shown. A, Strain gradients along the hypocotyl of rapidly growing plants (between 120 and 136 h after germination), measured during the night phase. B, Strain gradients along the hypocotyl of rapidly growing plants (between 120 and 136 h after germination), measured during the day phase. C, Strain gradients along hypocotyls, in which elongation growth had ceased (260 h after germination). In A, B, and C, turgor-induced elastic strain was calculated using shrinkage data measured immediately after freezing/thawing (○; second-order polynomial fits given as solid bold lines, with 95% confidence intervals shown as fine dashed lines). For comparison, strain profiles based on shrinkage determined 20 h after freezing/thawing are shown as well (bold dashed lines). The shape of the profiles is similar, irrespective of the time passing before the determination of plasmolytically induced shrinkage.