Resurrection of the Fern "Cheilanthes albomarginata Clarke" Involves Utilization of Trehalose as Energy Source and Accumulation of Protective Stress Metabolites

Most plants are unable to survive desiccation to an air-dried state, but a small group of plants known as resurrection plants can tolerate extreme desiccation, and regain normal function after rehydration. Cheilanthes albomarginata is one such resurrection fern, which has been analyzed in this study for metabolite changes during resurrection. In this study, we have tested C. albomarginata fronds from ten different geographical regions of Himachal Pradesh for the presence of trehalose, proline, and glycine betaine. The profile of trehalose sugar during resurrection was investigated using chromatographic techniques and enzymatic assays. Analysis of extracted sugars by High performance liquid chromatography (HPLC) showed that trehalose levels were highest in dehydrated stage of C. albomarginata (46 %), which reduced to 28% upon rehydration. Fourier Transform InfraRed spectroscopy (FTIR) analysis of intracellular sugars in crude extracts of C. albomarginata indicated the closest match of the sugar in the samples with trehalose rather than sucrose. Quantitative estimation of extracted trehalose sugar of C. albomarginata using crude trehalase further confirmed the utilization of trehalose during resurrection. Thus, trehalose appears to be the major sugar accumulating during dehydrated condition, with an active role in resurrection of C. albomarginata. Proline and Glycine betaine were observed to accumulate during dehydration stage in C. albomarginata, and remained largely unaltered during rehydrated state, indicating their protective role during resurrection.