Ectopic Expression of Plant RNA Chaperone Offering Multiple Stress Tolerance in E. coli

Members of the plant glycine-rich RNA-binding proteins (GR-RBPs) family have been reported in flowering, development, circadian rhythms, biotic and abiotic stresses. Particularly, GR-RBPs are reported to function as RNA chaperones, promoting growth and acclimation during cold shock. It is indispensable to further question the efficacy and mechanism of GR-RBPs under various environmental strains. Monitoring the expression of stress-regulated proteins under stress conditions has been a beneficial strategy to study their functional roles. In an effort to elucidate the NtGR-RBP1 function, stress markers such as salinity, drought, low temperature and heat stresses were studied. The NtGR-RBP1 gene was expressed in E. coli followed by the exposure to stress conditions. Recombinant E. coli expressing NtGR-RBP1 were more tolerant to stresses, e.g., salinity, drought, cold and heat shock. Recombinants exhibited higher growth rates compared to control in spot assays. The tolerance was further confirmed by monitoring the growth in liquid culture assays. Cells expressing NtGR-RBP1 under salt (500 mM NaCl), drought (20% PEG), cold (4 and 20 °C) and heat stresses (50 °C) had enhanced growing ability and better endurance. Our study supports the notion that the protective role of NtGR-RBP1 may contribute to growth and survival during diverse environmental stresses.