One of the main problems for plants when they colonized terrestrial environments on Earth nearly a half billion years ago was how to survive the dryness.
Resurrection plants, however, display the remarkable ability to survive near total desiccation (less than 5% relative water content), which causes them to appear dead. But when rehydrated, these plants can be revived. Hence, they are often referred to as “resurrection plants”.
Probably the most well-known is the species Selaginella lepidophylla
Briefly, the onset of water loss apparently sets into motion a series of cellular events that can be summarized as follows:
Dehydration –> Activation of “desiccation-related” genes –> (1) Alterations in metabolism and (2) Production of “protective” proteins
(1) Alterations in metabolism: (a) accumulation of protective solutes such as sucrose, trehalose, and proline that stabilize proteins and cellular membranes, (b) production of antioxidant compounds (such as galloylquinic acids), and (c) biochemical alterations in membrane and cell wall composition.
(2) Production of “protective” proteins such as “dehydrins” and “expansins” that help preserve the structural integrity of intracellular organelles and the cell walls.
References
1. Moore, J.P., et al. (2006) “Response of the Leaf Cell Wall to Desiccation in the Resurrection Plant Myrothamnus flabellifolius.” Plant Physiology Vol. 141, pp. 651–662.
2. Layton, B.E., et al. (2010) “Dehydration-induced expression of a 31-kDa dehydrin in Polypodium polypodioides (Polypodiaceae) may enable large, reversible deformation of cell walls.” American Journal of Botany Vol. 97, pp. 535-544.
3. Moore, J.P., et al. (2009) “Towards a systems-based understanding of plant desiccation tolerance.” Trends in Plant Science Vol. 14, pp. 110-117.
And this amazing plants are at the basis of a long-term thermostabilization process to preserve vaccines,
here some more details:
http://www.thenakedscientists.com/HTML/content/interviews/interview/1281/
http://stm.sciencemag.org/content/2/19/19ra12.abstract
http://www.dailymail.co.uk/health/article-322568/Vaccine-breakthrough-revolutionise-Third-World-health.html
http://www.ncbi.nlm.nih.gov/pubmed/17661683
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