Effects of Vibrio parahaemolyticus on activities of respiratoryrelated enzymes and gene expression of antioxidant enzymes in hepatopancreas and gill of Macrobrachium rosenbergii

【Objective】To investigate the effects of Vibrio parahaemolyticus on the activities of respiratory-related enzymes and antioxidant enzyme genes in hepatopancreas and gill of Macrobrachium rosenbergii，in order to provide reference for the immune mechanism research and disease control of M. rosenbergii.【Method】Regular and healthy M. rosenbergii was selected and injected with PBS solution（control group）and V. parahaemolyticus（experimental group）respectively. The cumulative survival rate was counted at the 1，3，6，12，24，48，72 and 96 h，and the activities of respiratory related enzymes and the expression of antioxidant enzyme related genes were measured in hepatopancreas and gill tissues.【Result】After being infected with V. parahaemolyticus，the cumulative survival rate of M. rosenbergii gradually decreased with the passage of time，and the cumulative survival rate was 72% at 96 h. After infection with V. parahaemolyticus，compared with the control group，the activities of ATP synthase，cytochrome C oxidase and NADH dehydrogenase in the hepatopancreas of M. rosenbergii in the experimental group decreased at first and then increased and finally tended to be the level of the control group. At 6 to 24 h，the activities of the three enzymes were significantly lower than those in the control group（P<0.05，the same below），and then gradually increased. The reactive oxygen species（ROS）content increased at first and then decreased，and was significantly higher than that in control group at 6-48 h. Superoxide dismutase （SOD）gene，catalase（CAT）gene and glutathione peroxidase（GPX）gene increased at first，then decreased and then increased. In the gill tissue of M. rosenbergii in the experimental group，the activities of ATP synthase，cytochrome C oxidase and NADH dehydrogenase decreased at first and then increased to the level of the control group，and the activities of the three enzymes decreased significantly at 6-72 h. The activity of reactive oxygen species increased at first and then decreased. The relative expression of SOD gene，CAT gene and GPX gene increased first，then decreased and finally increased，and both of them significantly increased to the maximum at 6 h after infection，in which the relative expression of GPX gene significantly decreased from 12-48 h to lower than that of the control group，and gradually increased at 72 h. 【Conclusion】V. parahaemolyticus infection of M. rosenbergii has significant effect on antioxidant enzyme genes and respiratory-related enzymes in hepatopancreas and gill tissues，the level of ROS increases. Although M. rosenbergii can resist pathogen invasion by self-regulating antioxidant enzyme genes and respiratory-related enzymes，it will cause damage to the body when it exceeds the limit of self-regulation.