Effects of low temperature stress on activities of antioxidant enzymes，Na~+/-K~+-ATP enzyme and Hsp70 content of Nibea albiflora
LUO Sheng-yu；XU Dong-dong；LOU Bao；CHEN Rui-yi；ZHAN Wei；MAO Guo-ming；Zhejiang Ocean University；Zhejiang Province Key Lab of Mariculture and Enhancement，Marine Fishery Institute of Zhejiang Province；
In order to investigate the effects of low temperature treatment on the physiological function of juvenile Nibea albiflora，we investigated the effect of cold stress on activities of antioxidant enzymes，Na~+/-K~+-ATP enzyme and Hsp70 content in juvenile Nibea albiflora.Four treatments were set up，and 18℃was as the control and 8℃，10℃and 14℃groups were as experimental groups.We measured the activities of antioxidant enzymes，Na~+K~+-ATP enzymes and Hsp70 content of N. albiflora at different temperatures.The results showed that the temperature significantly influenced the SOD and CAT enzyme activities，and Na~+/-K~+-ATP enzyme activities and Hsp70 content of N. albiflora.The results showed that antioxidant enzyme activities increased in the beginning and then decreased under the low temperature stress，and at 72 h post-stress，antioxidant enzyme activities in low temperature treatments were at the same level as the control（P > 0.05）.Na~+/-K~+-ATP enzyme activities in the muscles of low temperature treatments showed the trend of decreasing firstly and then rising during the process of cold temperature stress.The Na~+/-K~+-ATP enzyme activities of 10℃and 14℃treatments could recover and have no significant differences at 72 h post-stress compared with the 18℃treatment，but the activities of Na~+/-K~+-ATP enzyme in 8℃treatment remained lower at 72 h post-stress.The Hsp70 contents in different treatments were also impacted by the low temperature，and showed the trend of increasing firstly and then decreasing during the process of cold temperature stress.Compared with the control，the Hsp70 contents of 10℃and 14℃treatments recovered and showed insignificant differences at 72 h post-stress.However，the Hsp70 contents remained higher than that of control at 72 h post-stress.Therefore，SOD，CAT，Na~+/-K~+-ATPase and Hsp70 were involved in the process when N. albiflora was responding to low temperature stress，and they could be the markers corresponding to cold stress in N. albiflora.
