温度胁迫对皱纹盘鲍生理和生化活动的影响

为探讨温度胁迫下皱纹盘鲍(Haliotis discus hannai Ino)的响应机制,采用室内控温实验,通过设置4个温度梯度(5℃、10℃、20℃和25℃),设计温度骤变处理组(皱纹盘鲍从15℃暂养温度直接转移至各实验温度)和温度缓变处理组(0.5℃/12 h),分析温度剧烈变化和温度缓慢变化对皱纹盘鲍耗氧率和排氨率的影响及其差异性;并对高温和低温处理下皱纹盘鲍消化腺中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、酸性磷酸酶(ACP)和溶菌酶(LSZ)活性的变化情况以及不同组织(血细胞和肌肉组织)中Cu/Zn–SOD基因的表达状况进行了研究。结果表明,皱纹盘鲍耗氧率和排氨率随海水温度的升高而增加,20℃达到最高值;25℃骤变处理组与缓变处理组耗氧率和排氨率间存在极显著差异(P0.01)。5℃和10℃骤变处理组皱纹盘鲍氧氮比(O/N)同缓变处理组间存在极显著差异(P0.01)。在高温胁迫后的3 h,消化腺中SOD、CAT和LSZ活性达到最高,而ACP活性在胁迫6 h后达到最高(P0.01);低温胁迫显著降低皱纹盘鲍LSZ的活性,于胁迫9 h后达到最低(P0.01)。不同温度胁迫下,皱纹盘鲍血细胞和肌肉组织中Cu/Zn–SOD基因的相对表达量均表现上调,与对照组存在显著差异性(P0.05)。本研究表明,温度胁迫能显著影响皱纹盘鲍的生理和生化活动,这将有助于探讨皱纹盘鲍夏季高死亡率的原因,为皱纹盘鲍健康养殖提供一定的理论依据。

Effects of temperature change on physiological and biochemical activities of Haliotis discus hannai Ino

The effects of changes in temperature on physiological and biochemical activities of Haliotis discus hannai Ino were studied in the laboratory to better understand the thermal tolerance mechanisms of abalone. Aba-lone were transferred abruptly from a rearing temperature (15℃, control temperature) to 5℃, 10℃, 20℃, or 25℃. Other groups of abalone were acclimated to different experimental temperatures (5℃, 10℃, 20℃, and 25℃) by gradually increasing or decreasing seawater temperature (0.5℃/12 h). Then, oxygen consumption and ammonia excretion rates of H. discus hannai Ino were measured, the activities of superoxide dismutase (SOD), catalase, acid phosphatase and lysozyme (LSZ) in the digestive gland were determined, and Cu/Zn–SOD gene expression levels in hemocytes and muscle were determined. The results showed that oxygen consumption and ammonia-N excretion rates of H. discus hannai Ino increased gradually with an increase in water temperature and peaked at 20℃. The rates of oxygen consumption and ammonia-N excretion in the 25℃-acute temperature change treatment were significantly higher than those in the gradual treatment (P<0.01). Moreover, significant differences in the abalone O/N ratio were observed between the acute and gradual temperature change treatments at 5℃ and 10℃ (P<0.01). SOD, catalase, acid phosphatase, and LSZ activities increased significantly in abalone exposed to high temperature (25℃) for 72 h and reached the maximum at 3 h or 6 h (P<0.01). However, a significant decrease in LSZ activity was found in abalone in the 5℃-acute temperature change treatment and reached the lowest level after 9 h (P<0.01). Significantly up regulated Cu/Zn–SOD gene expression was also observed in hemocytes and muscle in abalone from the different temperature treatments (P<0.05). The physiological and biochemical activi-ties of H. discus hannai Ino were significantly affected by temperature. These data provide valuable insight into the possible mechanisms of abalone summer mortalities and will serve as a theoretical basis for healthy breeding of abalone.