Multi-omics insights into antioxidant and immune responses in Penaeus monodon under ammonia-N, low salinity, and combined stress

Ammonia nitrogen and salinity are critical environmental factors that significantly impact marine organisms and present substantial threats to Penaeus monodon species within aquaculture systems. This study utilized a comprehensive multi-omics approach, encompassing transcriptomics, metabolomics, and gut microbiome analysis, to systematically examine the biological responses of shrimp subjected to low salinity, ammonia nitrogen stress, and their combined conditions. Metabolomic analysis demonstrated that exposure to ammonia nitrogen stress markedly influenced the concentrations of antioxidant-related metabolites, such as glutathione, suggesting that shrimp mitigate oxidative stress by augmenting their antioxidant capacity. The transcriptomic analysis revealed an upregulation of genes linked to energy metabolism and immune responses and antioxidant enzymes. Concurrently, gut microbiome analysis demonstrated that ammonia nitrogen stress resulted in a marked increase in Vibrio populations and a significant decrease in Photobacterium, indicating that alterations in microbial community structure are intricately associated with the shrimp stress response. A comprehensive analysis further indicated that the combined stressors of ammonia nitrogen and salinity exert a synergistic effect on the immune function and physiological homeostasis of shrimp by modulating antioxidant metabolic pathways and gut microbial communities. These findings provide critical systematic data for elucidating the mechanisms through which ammonia nitrogen and salinity influence marine ecosystems, offering substantial implications for environmental protection and ecological management.