The response mechanism of high pH and alkalinity interactive stress on immune system and energy metabolism pathway of Litopenaeus vannamei

Abstract

Litopenaeus vannamei is an important aquaculture species and faces complex stress challenges in saline-alkali water, such as high pH and alkalinity. In this study, the immune and metabolic responses of L.vannamei under acute interactive stress (pH 9.2, alkalinity 350 mg / L) were investigated by multi-omics analysis. The results showed that significant changes in antioxidant enzyme activity (e.g., increased SOD, decreased GSH-Px) and immune-related pathways (lysosomes, TGF-β, glutathione metabolism) were affected. Transcriptome analysis identified 1968 DEGs, which were mainly enriched in apoptosis, immune defense, and energy metabolism pathways. Metabolomics revealed the disorder of lipid, amino acid, and nucleotide metabolism, and key metabolites (such as arachidonic acid and sphingomyelin) were related to oxidative stress and membrane stability. Multi-omics integration showed that PI3K-AKT and TGF-β signaling pathways were coordinated and regulated under stress conditions. WGCNA analysis obtained a total of 19 co-expression modules. Among them, 13 hub genes related to saline-alkali stress were screened out in the turquoise and brown modules, and a transcriptional regulatory network was constructed. The expression patterns of five pairs of genes in four hot pathways under saline-alkali stress were verified. In summary, high pH and alkalinity interaction stress induces oxidative damage, disrupts metabolic homeostasis, and triggers adaptive responses through immune activation and energy redistribution. This study provides clues for exploring the molecular response mechanism of L. vannamei under saline-alkali stress and provides a theoretical basis for optimizing shrimp culture in saline-alkali waters.