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Drying without dying: the comparative mechanisms and evolution of desiccation tolerance in animals, microbes, and plants

Symposium organized by Peter Alpert, James Clegg, Brent Mishler, and Mel Oliver




The fly Polypedilum vanderplanki is the only insect known to tolerate desiccation. Its larva can recover from a fully dried, inactive state (0 min) to a fully hydrated and active one in less than one hour (44 min). Photo by Takashi Okuda.


Southern Africa is a center of diversity of desiccation- tolerant flowering plants, such as the shrub Myriothamnus flabellifolia. Photo by Jill Farrant.


The anhydrobiotic bdelloid rotifer Philodina roseola. Photo by Alan Tunnacliffe



For most organisms, drying to equilibrium with even moderately humid air is fatal. Accordingly, mechanisms to acquire and conserve water are one of the most conspicuous features of life on land. However, at least three phyla of animals and all but one of the major plant taxa also contain species that tolerate desiccation. Recent comparisons of desiccation-tolerant plants suggest that tolerance has evolved many times, converged on similar biochemical mechanisms, and entrained parallel trade offs between tolerance and both complexity and productivity. This symposium will extend this comparison to include animals and microbes, providing the first synthesis of knowledge of desiccation tolerance across all the major kingdoms of life in over 15 years. The symposium will integrate studies of the biophysics, biochemistry, genetics, anatomy, physiology, and ecology of tolerance to help understand the comparative mechanisms of tolerance and the evolutionary basis for the apparent trade off between tolerance and growth.

Technical advances in molecular biology have stimulated a recent flush of integrative, basic research on desiccation tolerance in plants. One important practical application could be in genetic engineering of tolerance in crops. Likewise, research is being done on the use of knowledge gained from the study of desiccation-tolerant animals to stabilize and make stress-resistant mammalian cells in culture - even human blood platelets. These results could find ready application in the current emphasis on using "lessons from nature" to induce stability and stress resistance in a wide variety of biological systems. The time has come to integrate these two bodies of research and to compare their lessons for agriculture and health. The symposium will take place on two of the days of the SICB meeting and be published as a special issue of the journal Integrative and Comparative Biology.


Schedule


January 5

9:00 am. Peter Alpert, University of Massachusetts at Amherst, USA: "The constraints of tolerance: why are desiccation-tolerant organisms small and rare?"

9:30 am. Amy Treonis, Creighton University, USA (co-authored with Diana Wall, Colorado State University, USA): "Worms bite the dust: ecological tradeoffs for nematode survival in arid environments"

10:00 am. coffee break

10:30 am. Ingemar Jönsson, University of Lund, Sweden: "A life history perspective on desiccation tolerance"

11:00 am. Brent Mishler, University of California at Berkeley, USA : "The evolution and ecology of desiccation tolerance in mosses"

11:30 am. Mel Oliver, Agricultural Research Service, US Dept. of Agriculture, USA "Desiccation tolerance in bryophytes: evidence for whether tolerance is the primitive condition in plants"

12:00 pm. lunch break

1:00 pm. Dorothea Bartels, University of Bonn, Germany "The evolution of desiccation tolerance in higher plants: genomic aspects"

1:30 pm. Malcolm Potts, Virginia Tech, USA: "The desiccome: humble beginnings"

2:00 pm. Folkert Hoekstra, Wageningen Agricultural University, The Netherlands: "Differential storage behavior in dried pollen and spores"

2:30 pm. Chris Walters, Colorado State University, USA: "Dying while dry: kinetics and mechanisms of deterioration in desiccated organisms"

3:00 pm. adjournment for the day

January 6

8:30 am. Ilse Kranner, Royal Botanical Gardens at Kew, UK: "The lichen symbiosis - antioxidants confer desiccation tolerance"

9:00 am. Jill Farrant, University of Cape Town, South Africa: "Molecular, biochemical and physiological mechanisms of desiccation tolerance in a range of angiosperm resurrection plants"

9:30 am. Alan Tunnacliffe, Cambridge University, UK

"Molecular anhydrobiology"

10:00 am. coffee break

10:30 am. Takashi Okuda, National Institute of Agrobiological Sciences, Japan "Anhydrobiosis in an African chironomid"

11:00 pm. James Clegg, University of California at Davis, USA: "Adaptations underlying severe desiccation tolerance in the animal extremophile, Artemia"

11:30 am. John Crowe, University of California at Davis, USA: "Real-world applications of lessons learned from the world of anhydrobiosis"

12:00 pm. adjournment

[a workshop on integrating ecology, systematics, physiology, and genomics to study desiccation tolerance and other biological phenomena is in planning for a two-hour period In the afternoon or evening following the symposium]



For more information, please contact: Peter Alpert, Biology Department, University of Massachusetts, 611 North Pleasant St., Amherst, MA 01003-9297, USA; phone: 1 413 545 4357; fax: 1 413 545 3243; email: palpert@bio.umass.edu