Investigation of Ionic Response Characteristics and Homeostatic Mechanisms in Chlorella pyrenoidosa under Saline-Alkali Stress

This study utilized Chlorella pyrenoidosa as the experimental organism. To simulate saline-alkali stress conditions, various concentration gradients of Na2CO3 and NaHCO3 ( 0-0.1 mmol/L) were established. By integrating physiological phenotypic observations, ionomic profiling, and eukaryotic reference transcriptome analysis, the ion-responsive characteristics and underlying mechanisms of homeostasis maintenance under saline-alkali stress were thoroughly examined. Experimental results demonstrate that saline-alkali stress significantly suppresses algal cell growth, while concurrently enhancing lipid accumulation and antioxidant enzyme activities (SOD, POD, CAT, MDA) at certain concentration levels. Ionomic analysis showed significant alterations in intracellular ion content in Chlorella pyrenoidosa under saline-alkali stress conditions compared to the control group. Transcriptome sequencing revealed a total of 10,596 expressed genes and clarified the functional pathways associated with differentially expressed genes. Integrated multi-omics correlation analysis elucidates the molecular mechanisms underlying salt-alkali tolerance in Chlorella pyrenoidosa, thereby offering a theoretical foundation for the application of microalgae in the bioremediation of saline-alkali wastewater and the development of bioenergy.