• Desiccation tolerance;
  • Cyanobacteria;
  • Nostoc commune;
  • RNA polymerase;
  • Gene expression

Abstract Immobilization and short-term air-drying of the cyanobacterium Nostoc commune strain UTEX 584 leads to a complete depletion of its cellular rpoC1C2 mRNA pool. This mRNA is required for the synthesis of the γ and β′ subunits of DNA-dependent RNA polymerase (RNA-P). In contrast, RNA-P remains stable in cells during long-term desiccation as judged from immunoblotting analyses of protein extracts using RNA-P core-specific antibodies. The data indicate that the extant RNA-P holoenzyme in air-dried cells drives the rapid de novo transcription of rpoC1C2 that ensues in response to cell rehydration.