Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 5/1/2007
Publication Date: 12/1/2007
Citation: Walters, C. and K.L. Koster. 2007. Structural Dynamic and Desiccation Damage in Plant reproductive Organs. p. 251-280. In Jenks, M.A. and Wood A. (eds)Plant Desiccation Tolerance. Blackwell publishing, Oxford, U.K. Interpretive Summary: Most biological systems (organisms, cells, biomolecules) are damaged when they are dried. Yet, drying is a critical part of most preservation treatments. This paradox suggests why it is so difficult to pinpoint the lethal effects of drying. In this chapter, direct and indirect effects of dehydration on cell structure and chemistry are reviewed in the context of recent advances in understanding stabilization of biomolecules from the food and pharmaceutical perspectives.
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.