Enzyme Dynamics of the Resurrection Plant Selaginella lepidophylla (Hook. & Grev.) Spring during Rehydration

The activities of 10 enzymes involved in carbohydrate metabolism were measured in both desiccated and rehydrated fronds of the desiccation-tolerant pteridophyte Selaginella lepidophylla (Hook. & Grev.) Spring. Enzyme conservation was defined as the ratio of desiccated to hydrated frond enzyme activity. The mean level of conservation was 74%, with nine of the 10 enzymes showing significant activity increases (P<0.05) during hydration. The mean of photosynthetic enzyme conservation was significantly lower (P=0.05) than the mean for glycolytic and respiratory enzymes combined. Chloramphenicol inhibited the normal activity increase in ribulose bisphosphate carboxylase and (NADPH)triose-P dehydrogenase but not pyruvate kinase upon rehydration. Cycloheximide did not affect the normal activity increase for these three enzymes. It is concluded that substantial enzyme conservation is beneficial for rapid resumption of metabolic activity in resurrection plants.