Research progress on effects of salinity stress on immune function and mechanism in shellfish
Shellfish aquaculture has become an important part of China's marine economic development.In recent years,environmental deterioration has intensified,and the scale of shellfish culture has gradually increased,resulting in increase in disease incidence and decrease in economic benefits.Shellfish is not only affected by biotic stressors such as viruses,bacteria and parasites,but also by abiotic stressors such as temperature,dissolved oxygen,pH and salinity.Salinity is an important ecological factor in marine ecosystems,directly affecting the osmotic pressure of marine animals and indirectly affecting their survival,growth,and reproduction.The salinity of surface seawater and nearshore water is inclined to decrease during rainy seasons due to precipitation,resulting in increased mortality and changes in the spatial distribution of many marine organisms.Extreme fluctuations in salinity can defeat the defences and cause varying degrees of damage to marine molluscs,even may lead to mortalities and heavy economic losses.The effects of salinity stress on shellfish culture have gradually become a research focus.The immune function of shellfish mainly consists of cellular immunity and humoral immunity.The number of blood cells and phagocytosis are important factors in the immunity of shellfish.Immune factors such as superoxide dismutase(SOD),catalase(CAT),lysozyme(LZM)and acid phosphatase(ACP)are important members of phagocytosis and are effective indicators to assess the effect of the environment on life form.Existing studies have shown that salinity stress can cause physiological and biochemical changes in shellfish to reduce metabolic levels such as feeding,destroy the stability of shellfish's internal environment and reduce shellfish's ability to resist pathogen invasion and respond to external environmental stimuli,thereby adversely affecting shellfish's growth and immunity,and it may eventually lead to the death of stressed shellfish.Salinity stress can accelerate reactive oxygen species(ROS)in organisms,induce oxidative stress in shellfish,and significantly change anti-stress related genes expression response to maintain cell stability and survival.Both high and low salinity stress can change the physiological activities and states of marine shellfish.This paper summarizes the immune system of shellfish,reviews and analyzes the response mechanisms to salinity stress including shellfish immune function,stress response genes and their expression regulation.The paper is to provide a reference for understanding the immune function of shellfish and the response mechanism of shellfish to salinity stress,prevent shellfish diseases,facilitate the investigation of the breeding of salt-resistant varieties of shellfish.
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维普
