Desiccation tolerance and sensitivity in plants

Abstract

With the pressing issues surrounding the predicted alterations in climate and the growing need to increase agricultural production to service a growing world population, the desire to comprehend how plants tolerate abiotic stress events has grown in intensity over the past decade. Since a number of climate models emphasize the importance of water availability and the vulnerability of world agriculture (and society) to drought, an understanding of how plants tolerate water deficits has now become a priority. Much has been learnt from the intense study of model plants and a few select crops that are relatively sensitive to water deficits such as Arabidopsis, tomato, and maize, but despite this intense activity we still have little understanding of the adaptive value of how plants respond, or functional knowledge of the genes that respond, to cellular dehydration. At this point it is still uncertain which responses and genes are associated with the establishment of tolerance (or promoting adaptation to dehydration) and which relate more closely to the processes of cellular injury associated with water loss. In addition, as most of the plants studied so far tolerate only mild water deficits, it is possible that processes and genes important in dehydration tolerance have yet to be revealed. The aforementioned pressing agricultural issues and the desire to identify key adaptive processes and genes associated with tolerance of dehydration have prompted a resurgence of interest in the phenomenon of cellular desiccation tolerance in plants. Understanding how plant cells tolerate and survive the extremes of cellular dehydration in combination with our ever increasing understanding of how sensitive plants respond to water deficits will prove invaluable in generating ideas and mechanisms for improving the ability of the world’s most important food and fibre crops to tolerate drought. Indeed, much of the support for the many hypotheses concerning the PHYSIOLOGIA PLANTARUM 122: 1–2. 2004 doi: 10.1111/j.1399-3054.2004.00379.x Printed inDenmark – all rights reserved Copyright#PhysiologiaPlantarum2004