Physiology and Ultrastructure of Desiccation in the Green Alga Prasiola crispa from Antarctica

Physiological and fine structural responses of the antarctic green alga Prasiola crispa ssp. antarctica (Kutz.) Knebel to desiccation and reimmersion in seawater are described. Experiments were conducted in the dark over a 14 day period, using a range of relative humidities (5% to 95%). Emersed thalli lost about 75% of the total cellular water during 6 hours of desiccation. Maximum water loss (86%) occurred after 1 day exposure to 50% relative humidity (r. h.), and then remained stable for 14 days. Water loss of more than 90% led to irreversible damage of the plants (...)