On the Cover: The cereal aleurone is a specialized layer of the endosperm that responds to GA by producing hydrolytic enzymes. These enzymes then break down storage reserves in the starchy endosperm to fuel germination and early seedling growth. The dose response of isolated aleurone cells to GA covers a very broad range of concentrations (several orders of magnitude), but the molecular basis for this large range of hormone sensitivity remains unknown. The cover photograph shows a population of aleurone protoplasts treated with a single GA concentration and exhibiting different degrees of vacuolation characteristic of different degrees of the GA resonse. These and other observations reported by Ritchie et al. (pp. 361-370) indicate that the aleurone tissue consists of cells with differing sensitivities to GA. The wide GA dose response of this tissue is due to progressive recruitment of cells from these subpopulations with different hormone response thresholds located in different regions of the seed.