MOLECULAR CHARACTERIZATION OF THE REHYDRATION PROCESS IN THE RESURRECTION PLANT CRATEROSTIGMA-PLANTAGINEUM

The resurrection plant Craterostigma plantagineum is unique among high er plants because it is able to survive a desiccation treatment. For t his reason it has been used as a model system for the analysis of the molecular mechanisms of desiccation tolerance. Many transcripts and pr oteins are expressed de novo during dehydration. This paper describes the molecular events that occur during the rehydration process of drie d C. plantagineum plants. Changes in gene expression patterns were fir st analyzed by in vivo labeling and in vitro translation experiments. In a second set of experiments steady-state mRNA levels were monitored using specific cDNA clones. The experiments indicated three major cha nges on the molecular level during rehydration: the dehydration-specif ic gene products disappeared during an early phase of rehydration, a s mall number of rehydration-specific transcripts were synthesized aroun d 12 to 15 h after the onset of rewatering, and hydration-related gene products appeared concomitantly. The gene expression patterns during rehydration are discussed with respect to the possible roles of the ge ne products.