游出超, 董兰芳, 曾梦清, 蒋艳, 许明珠, 张琴
广西壮族自治区海洋研究所 广西海洋生物技术重点实验室, 广西 北海 536000

摘要:
为探讨低盐度急性胁迫对可口革囊星虫（Phascolosoma esculenta）的影响规律，研究星虫对急性低盐度胁迫的响应机制，本试验先通过急性毒性试验确定星虫96 h内对低盐度的耐受范围，再选取96 h最小死亡率盐度，研究该盐度急性胁迫下星虫（平均体质量0.85±0.07 g）体质量、体壁含水量、Na⁺/K⁺-ATP酶活力以及酸碱磷酸酶活力在96 h内的动态变化。结果表明：在本试验盐度3.0~7.0范围内，可口革囊星虫24 h的最大死亡率盐度是3.0，96 h的最小死亡率盐度为7.0；星虫死亡率随盐度降低逐渐升高，但相同盐度下随着时间延长，星虫死亡率基本不变，可口革囊星虫96h内能耐受的最低盐度是7.0；在低盐度7.0胁迫下，星虫体质量和体壁含水量在12 h内显著增大（P<0.05），12 h后趋于平稳（P>0.05）；Na⁺/K⁺-ATP酶活力也在6 h内显著升高至最大值（P<0.05），6 h至12h又显著降低（P<0.05），此后稳定在高于对照组水平；酸性磷酸酶和碱性磷酸酶活力变化趋势与Na⁺/K⁺-ATP酶活力类似，均是先显著升高（P<0.05）后显著降低（P<0.05），最后稳定在高于对照组水平。以上研究表明，可口革囊星虫能够通过Na⁺/K⁺-ATP酶、酸碱磷酸酶等渗透和免疫相关的生理调节机制，迅速响应低盐度环境，其对低盐度有很强的适应力和耐受力。
关键词:低盐度胁迫可口革囊星虫Na⁺/K⁺-ATP酶磷酸酶
DOI：10.11759/hykx20190117001
分类号:Q958.11
基金项目:广西创新驱动发展专项资金项目（桂科AA17204044），广西科学研究与技术开发计划项目（桂科攻14121006-2-3）

Effect of Acute Low-Salinity Stress on the Survival and Na⁺/K⁺-ATPase and Phosphatase Activities of Phascolosoma esculenta
YOU Chu-chao, DONG Lan-fang, ZENG Meng-qing, JIANG Yan, XU Ming-zhu, ZHANG Qin
Guangxi Institute of Oceanology, Key Laboratory of Marine Biotechnology of Guangxi, Beihai 536000
Abstract:
To analyze the effect of acute low-salinity stress on Phascolosoma esculenta (P. esculenta) and its response mechanism, acute toxicity testing was first conducted to determine the tolerance range of P. esculenta to low salinity within 96 h. Furthermore, the salinity of minimum mortality rate at 96 h were determined to culture P. esculenta, which investigate the dynamic changes of the body mass, water content of the body wall, and Na⁺/K⁺-ATPase and phosphatase activities of P. esculenta (average body mass of 0.85 ±0.07 g) under this acute low-salinity stress within 96 h. The results showed that in the test range (3.0-7.0) of salinity, the maximum salinity at 24 h and minimum salinity at 96 h were 3.0 and 7.0, respectively. The mortality rate of P. esculenta gradually increased with the decrease in salinity from 7.0 to 3.0. However, with the same salinity, the mortality rate remained unchanged with the increase in time. The minimum salinity that P. esculenta can tolerate within 96 h is 7.0. The Na⁺/K⁺-ATPase activity also increased significantly to the maximum value within 6 h (P < 0.05) and decreased significantly from 6 h to 12 h (P < 0.05). Subsequently, the Na⁺/K⁺-ATPase activity stabilized at a higher level than the control group. The activities of acid phosphatase and alkaline phosphatase were similar to that of Na⁺/K⁺-ATPase, both of which initially increased significantly (P < 0.05), then significantly decreased (P < 0.05), and finally stabilized at a higher level than the control group. In conclusion, P. esculenta was able to rapidly respond to the low-salinity environment through the physiological regulation mechanism related to osmosis and immunity, such as Na⁺/K⁺-ATPase, acid phosphatase, and alkaline phosphatase, and exhibited strong adaptability and tolerance to low salinity.
Key words:low-salinity stressPhascolosoma esculentaNa⁺/K⁺-ATPaseacid phosphatasealkaline phosphatase





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