Desiccation-tolerance (DT) is the ability to lose virtually all free intracellular water and then recover normal physiological functions. The phenomenon of desiccation tolerance is present in higher plants as well as few Pteridophytes which with stand drying up to 1020% of their dry weight and still resume metabolism following rehydration. The present investigation was carried to understand the biochemical adaptations against desiccation and also subsequent rehydration in Adiantum raddianum (AR) an Omni present fern in the Devarayanadurga forest region of Tumakuru district of Karnataka, India. Detached fronds from healthy AR fern were fully hydrated, subsequently desiccated and rehydrated under in vitro conditions. During the desiccation process the relative water content (RWC) of detached fronds decreased to as low as 16% after 4 hours with intense inward curving. Upon rehydration, the RWC of the desiccated fronds regained 85% of the initial water content within 4 hrs. The rehydrated fronds almost showed the original morphology. Further, physiological activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and glutathione reductase (GR), lipid peroxidation and proline increased during desiccation but sucrose and starch content showed differential response. The result obtained in this study reveals that Adiantum raddianum has desiccation tolerant properties.
Key words: Keywords: Adiantum raddianum, Desiccation, Rehydration, RWC, proline, lipid peroxidation, antioxidants.
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