Transcriptome Analysis of Penaeus vannamei Hepatopancreas in Response to Lactococcus garvieae Infection in Low Salinity

Lactococcus garvieae infection significantly affects the health of the white shrimp, Penaeus vannamei, particularly under low salinity conditions (5 ppt). Despite being a euryhaline species, shrimp become more vulnerable to stressors when exposed to low salinity, which can lead to disease outbreaks in aquaculture systems. In this study, we conducted RNA-Seq analysis on hepatopancreatic tissue from shrimp exposed to both low salinity and L. garvieae. The differential transcript analysis revealed 294 transcripts: 234 upregulated and 60 downregulated in shrimp under combined stress conditions. Gene Ontology (GO) analysis indicated that many differentially expressed genes were linked to biological processes, particularly peptidase inhibitory and regulatory activities. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the ECM-receptor interaction pathway was upregulated, while pathways related to gluconeogenesis and metabolism were downregulated. The ECM-receptor pathway involved critical genes such as integrin β PS3, laminin, collagen and thrombospondins (THBS). This research provides insights into the molecular responses of shrimp to L. garvieae infection and low salinity stress.