短期高盐胁迫对脆江蓠抗氧化酶活性及光合酶活性的影响

Effects of Short Period High-Salinity Stress on Antioxidant Enzyme Activities and Photosynthesis Enzyme Activities of Gracilaria chouae

中文关键词: 脆江蓠  高盐胁迫  抗氧化酶  光合酶

英文关键词: Gracilaria chouae  High-salinity stress  Antioxidant enzyme  Photosynthetic enzymes

中文摘要:

      采用实验生态学方法，研究了脆江蓠(Gracilaria chouae)相关酶活性对短期高盐胁迫的响应，旨在为提高脆江蓠规模化养殖夹苗效率提供理论依据。实验设置5个盐度梯度(40、45、50、55和60)，自然海水作为对照组，研究了高盐处理0.5 h及自然海水恢复12和24 h对脆江蓠抗氧化酶和光合酶活性的影响。结果显示，高盐胁迫0.5 h后，随盐度的升高，脆江蓠的抗氧化酶中，超氧化物歧化酶(SOD)活性逐渐升高(P<0.05)，过氧化物酶(POD)活性呈波动变化(P<0.05)，过氧化氢酶(CAT)活性逐渐降低但差异不显著(P>0.05)，丙二醛(MDA)含量随盐度升高显著升高(P<0.01)，上述抗氧化酶活性均在盐度50~55时出现极值；脆江蓠光合作用关键酶Rubisco活性随盐度升高逐渐降低(P<0.01)，碳酸酐酶(CA)含量随盐度增加略有增加(P<0.05)。随恢复时间的增加，脆江蓠SOD、POD和CAT活性逐渐升高(P<0.05)，MDA含量显著降低(P<0.05)；Rubisco活性逐渐升高(P<0.05)，CA含量呈波动变化。研究表明，短期高盐胁迫显著影响脆江蓠藻体抗氧化酶和光合酶活性，藻体通过提高抗氧化酶活性以及加强对无机碳的吸收利用来应对高盐胁迫，胁迫去除后逐渐恢复至正常水平。

英文摘要:

      The effects of acute hypersalinity stress on the antioxidant and photosynthetic enzyme activities of Gracilaria chouae were studied. Plants were exposed to different levels of salinity ranging from 33 (control) to 60 under laboratory conditions. After incubation, plants were then transferred to seawater with a controlled level of salinity and recovered after 12 or 24 hours, respectively. The activity of antioxidant enzyme SOD increased (P<0.05), the activity of POD was fluctuated (P<0.05), the activity of CAT gradually decreased without significant difference (P>0.05) but the content of MDA was significantly increased (P<0.01). The activity of SOD、POD、CAT and MDA reached the maximum in 50~55 psu groups but decreased significantly at salinity 60; The activity of Rubisco, a key enzyme in photosynthesis of C3, gradually decreased with the increase of salinity (P<0.01). The content of CA slightly increased with the increase of salinity (P<0.05). With the increase of recovery time, SOD, POD and CAT activities gradually increased (P<0.05), and the activity of each antioxidant enzyme showed a maximum value in 50~55 psu groups, but MDA content decreased considerably (P<0.05). Rubisco activity was significantly higher than that in 0.5 h (P<0.05), and CA content fluctuated with salinity. Short period high-salinity stress significantly affected the activities of antioxidant enzymes and photosynthetic enzymes in G. chouae. Algae responded to hypersalinity stress by increasing the activities of antioxidant enzymes, and enhancing the absorption and utilization of inorganic carbon by CA. The alga gradually returned to the normal level after the stress was removed. The purpose of this study is to provide a theoretical basis for improving the efficiency of large-scale cultivation of G. chouae, and to provide basic data for the study of salt tolerance mechanism of macroalgae.