Fig. 1. Generalized response of increase in seed water content during imbibition and germination at different water potentials. Phase I is imbibition, Phase II includes the onset of germination (increased metabolism and cell elongation) until the radicle emerges outside the seed coat (germination complete), and Phase III begins. Mitosis, O₂ uptake, and root growth rate increase rapidly in Phase III. Adapted from Bewley and Black (1994) and Bradford (1995).