Cell‐water deficit regulates expression of rpoC1C2 (RNA polymerase) at the level of mRNA in desiccation‐tolerant Nostoc commune UTEX 584 (Cyanobacteria)

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.