Responsive Mechanism Of Reef-Building Coral Rocks To Temperature Stress

Coral reef ecosystems are one of the most important marine ecosystems and are extremely rich in biodiversity.However,under the influence of global climate change and environmental pollution,the growth of reef-building corals is seriously threatened,and coral reefs around the world are rapidly degraded.There are reports that moderate temperature stress can improve coral tolerance,but for different species of coral domestication effect and coral response mechanism to temperature stress has not been clearly reported,this study intends to use indoor simulation experiments on corals to conduct short-term high temperature domestication stress simulation experiments to explore the response mechanism of coral temperature stress and different forms of coral domestication effect severance differences.This study conducted a simulation of temperature stress in Porites lutea,Pocillopora damicornis,Pavona decussata.Explore the coral in the temperature after receive the change of the quantity and the maximum light quantum yield,to study its tolerance to temperature.Through the coral Catalases,Superoxde dismutase,Glutamine synthetase and Caspase3 enzyme and Lipid peroxidase,Glutathione content changes,reef to study made in the short term,heat tolerance after domestication whether to increase and domestication influence hot stress tolerance mechanism,guide the coral transplantation to repair,provides the basis for coral reef ecosystem protection.1.This research shows that: 1 the coral under the temperature stress,the three kinds of reef building after 32 ? and 34 ? high temperature stress,coral symbionts zooxanthella(zooxanthellae)density,symbiotic zooxanthella dark adaptation after maximum light quantum yield will be reduced,but the cross peony coral zooxanthellae loss minimum,maximum light quantum yield decreased maximum;While staghorn cup corals lost the most amount of zooxanthellae,the maximum light quantum yield decreased the least,indicates that the three coral symbionts have different thermal tolerance to temperature.2.When corals were subjected to temperature stress,the activity changes of Catalase,Superoxde dismutase,Glutamine synthetase and Caspase3 enzyme,as well as the content changes of Lipid peroxidase and Glutathione were consistent among the three scleractinian corals under temperature stress at 32? and 34?,indicating that the three corals may have similar response mechanisms to temperature.3.When the three corals recovered from the 32? high temperature stress were subjected to the 34? high temperature stress,the heat resistance of the three corals was improved compared with the control group(without the high temperature stress),but the variation range was different,indicating that the symbionts' tolerance to temperature will be improved to a certain extent after the domestication of the three corals,but the domestication effect is not the same.4.Through the analysis of coral physiology indexes,coral under temperature stress response mechanism may be: temperature lead to receive free,further cause the decrease of maximum light quantum yield.Due to the rise of temperature and zooxanthella losses,coral intracellular reactive oxygen content increased.Coral intracellular reactive oxygen levels rise,will further activate the secretion of antioxidant enzymes,when high active oxygen content,will combine with unsaturated fatty acids on the cell membrane formation of Lipid peroxidase.Glutathione can react with reactive oxygen species,in order to protect the protein thiol is not damaged by reactive oxygen species,so as to cut down the content of Glutathione.Reduced Glutathione and active substances.The increase of the content will activate caspase-3,which will induce cell initiation and regulation.The loss of zooxanthellae will cause the coral cell color to become lighter,and the destruction of cell membrane and the initiation of cell apoptosis will cause the death of coral.This study found that the heat resistance of the three corals recovered after high temperature stress at 32 ° C was higher than that of the control group(not subjected to high temperature stress)when subjected to high temperature stress at 34°C,but the domestication effect of different coral species was different.Therefore,moderate high temperature stress will have a certain domestication effect on corals.The research results can be used to artificially enhance the heat resistance of corals and provide theoretical basis for the ecological restoration of coral reefs under the background of global warming.