Technical Abstract: Plant reproductive structures provide ideal systems to study the impact of water loss on cellular systems. Diverse physiologies in related taxa or among different organs (e.g., leaves, overwintering structures, pollen and embryos) allow us to compare sensitivities among structures and identify primary lesions and cascading effects resulting from water loss. Cellular membranes and the cytoskeleton are identified as primary sites of damage. Water deficit can also induce production of reactive oxygen species (ROS) that degrade all macromolecules. This chapter overviews some of these structural and biochemical changes and focuses on quantitation of damage in the context of the degree of stress and the time required for damage to occur. We borrow heavily from the pharmaceutical and food science literature where these questions apply to the stability of formulations as they are dried and stored. An important concept arising from these considerations is that desiccation tolerant and sensitive cells may not differ in the types of reactions that occur during dehydration; instead the difference may lie in the slower rates of inevitable damaging reactions in tolerant cells.