Effects of temperature and salinity on tissue structure, antioxidant capacity and heat shock protein gene expression of Penaeus monodon

Abstract

In order to explore the influence of temperature and salinity on stress response of P. monodon, four experimental groups were set, respectively were normal temperature and normal salt (Control group), normal temperature and low salt(Group A), high temperature and low salt(Group B), high temperature and normal salt(Group C). The stress experiment was conducted for 96 hours, and the activities of acid phosphatase(ACP), alkaline phosphatase(AKP), total superoxide dismutase (T-SOD) and total antioxidant capacity (T-AOC) in hepatopancreas, the changes of tissue structure and the expression of related heat shock protein genes were measured．The results showed that the branchial structures of the three stress groups were found to be damaged to varying degrees. In Group A, AKP and ACP levels increased initially and then decreased, while T-SOD levels decreased initially and then steadily increased. In Group B and Group C, the four enzymes showed similar trends.There was no significant difference in the expression level of Hsps in the low salt group. The expression levels of Hsp-10, Hsp-60 and Hsp-90 genes showed a similar trend, and the maximum expression levels of the four genes were all at 96h. The expression levels of Hsps in muscle tissue were similar to those in hepatopancreas tissue. However, the highest expression levels of Hsp-70 and Hsp-90 in high temperature and low salt group were at 24h. Through this work on P. monodon stress responses to high temperature and low salinity, we have gained a deeper understanding of the physiological responses to environmental stressors, which will be useful in the development of protective measures for the shrimps under aquaculture conditions that replicate these stressors.