Figure 9.

Time course of PME activities in the embryo and megagametophyte following incubation of intact seeds at different stages in water or GA₃. Intact yellow cedar seeds were subjected to a full dormancy-breaking treatment (A and B, after moist chilling), or were subjected to the dormancy-breaking treatment and then transferred to germination conditions for 4 d (C and D, germ.) or until the seeds had germinated and had achieved radicle lengths of 1 mm (E and F, post-germ.). Following moist chilling or during the germinative and post-germinative stages, seeds were incubated in water or 0.5 mm GA₃ and the total PME activities determined in the embryo and megagametophyte of the intact seeds by activity assays over an 8-d period. The incubation solutions (water and GA₃) were changed every 3 d.