Global Transcriptome Analysis Reveals Acclimation-Primed Processes Involved in the Acquisition of Desiccation Tolerance in Boea hygrometrica

Boea hygrometrica resurrection plants require a period of acclimation by slow soil-drying in order to survive a subse-quent period of rapid desiccation. The molecular basis of this observation was investigated by comparing gene expres-sion profiles under different degrees of water deprivation. Transcripts were clustered according to the expression profiles in plants that were air-dried (rapid desiccation), soil-dried (gradual desiccation), rehydrated (acclimated) and air-dried after acclimation. Although phenotypically in-distinguishable, it was shown by principal component ana-lysis that the gene expression profiles in rehydrated, acclimated plants resemble those of desiccated plants more closely than those of hydrated acclimated plants. Enrichment analysis based on gene ontology was performed to deconvolute the processes that accompanied desiccatio