Differential responses of Macrobrachium rosenbergii to initial and repeated low-temperature stress

Macrobrachium rosenbergii is indigenous to tropical and subtropical regions, exhibiting poor cold tolerance and is highly vulnerable to low-temperature. To explore whether this species possesses “cold stress memory” and the corresponding “low-temperature memory genes (LMGs)”, this study performed initial and repeated low-temperature stress on M. rosenbergii . The activities of antioxidant and immune defense enzymes, histopathological alterations, and transcriptome of the hepatopancreas were analyzed. The results showed that the antioxidant and immune defense capacities of the repeated stress group were significantly higher than those of the initial stress group, with more severe hepatopancreatic tissue damage observed in the latter; 151 differentially expressed genes were identified as potential LMGs, which are predominantly associated with functions in protein synthesis and energy metabolism, primarily enriched in biological processes and pathways such as carbohydrate metabolic process, glycolysis/gluconeogenesis, and lysosome. These findings demonstrate that the cold tolerance of M. rosenbergii is significantly enhanced upon re-exposure to low-temperature stress, confirming the existence of cold stress memory in this species, and the potential LMGs identified herein may serve as the molecular basis mediating this memory effect, providing essential foundational data for in-depth elucidation of the response mechanism of M. rosenbergii to repeated low-temperature stress.