Transcriptomic and physiological analysis of Dunaliella salina under sistan deep water in Iran

The freshwater crisis in arid and semi-arid regions has increasingly prompted the exploration of alternative water resources, such as deep groundwater. Consequently, this study employed RNA-Seq technology to investigate the effect of deep groundwater on the growth performance and transcriptomic changes of Dunaliella salina. The findings indicated that the unique chemical properties of deep groundwater, particularly the elevated concentrations of nitrate, sulfate, and fluoride, facilitated cell growth, pigment production, and alterations in gene expression. Mapping results revealed that from the 18,740 genes annotated in the Dunaliella reference genome, Transcripts were detected for 18,317 genes in the RNA-Seq data. Among these, 9892 genes demonstrated significant differential expression at the 0.01 threshold. Gene Ontology (GO) analysis revealed the upregulation of genes associated with ribosome synthesis, stress response, photosynthetic activities, and ion regulation. The reconstruction of the co-expression network for upregulated genes indicated that rpl3, rpl8, and prpl13, which displayed the highest direct connectivity with other genes in the network, are crucial for ribosomal structure and the translation process. The outcomes of this research offer important insights into the regulatory mechanisms of Dunaliella salina in response to varying water sources and may significantly contribute to the optimization and industrial utilization of this microalga.