| Abstract: | Detached fronds of Polypodium virginianum L. survived loss of65–70% of their fresh weight over 10 d of slow-drying.Drying over silica gel resulted in a faster rate of water loss,to a lower fresh weight, which the fronds did not survive. Whenfronds were incubated in abscisic acid for 24 h prior to silica-drying,the amount of water lost was reduced, resulting in survivalof the fronds upon subsequent rehydration. Incubation in abscisicacid for at least 18 h was necessary for survival. Fronds inwhich the final fresh weight after drying was below a criticalamount (i.e. to less than 25% original fresh weight) did notsurvive. A reasonable correlation could be drawn between electrolyteleakage upon rehydration and survival of somedesiccation treatments,although this was not always clear-cut, especially in frondsincubated in abscisic acid for an insufficient time to ensuresurvival. Several polypeptides were synthesized during slow-and silica-drying, and in response to abscisic acid. No novelpolypeptides were identified that were unique to the desiccationregimes which resulted in survival. Nor did ABA induce specificproteins in fronds desiccated after preincubation in this regulatorfor 24 h. Key words: Desiccation-tolerance, abscisic acid, protein synthesis, fern, Polypodium virginianum |
