| 摘要: |
| 以坛紫菜（Pyropia haitanensis）Z-61叶状体为材料，检测了高盐（110）胁迫与低盐（0）胁迫处理不同时间（0、4、8、24h和恢复4h）后叶状体中的羟自由基（·OH-）清除能力、过氧化氢(H2O2)含量、丙二醛(MDA)含量、超氧阴离子(O2-·)含量、超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性、抗坏血酸过氧化物酶(GSH)活性以及叶绿素荧光参数［包括PS II最大光化学效率（Fv/Fm）、表观光合电子传递效率（ETR）、非光化学荧光猝灭系数（NPQ）、实际光合作用效率Y(II)］的变化，以探究坛紫菜叶状体对不同盐度海水的耐受机制.结果表明，在高盐和低盐胁迫下，H2O2的含量和·OH-的清除能力随时间增加而呈现逐渐上升的趋势，而O2-·的含量在胁迫4h显著升高后无显著变化.且相比于高盐（110），低盐（0）胁迫下坛紫菜叶状体会产生更多 H2O2、O2-·和·OH-，膜脂过氧化物丙二醛（MDA）含量增加更明显，说明低盐胁迫引起坛紫菜叶状体的氧化损伤要显著高于高盐胁迫.高盐胁迫24h后，SOD的活性达到了最大，CAT、抗坏血酸过氧化物酶(APX)、谷胱甘肽(GSH)的活性均呈现先上升后下降的变化趋势.低盐胁迫下，SOD、GSH的活性均不断增加，CAT、APX的活性先上升后下降.此外，低盐和高盐胁迫下，随时间的增加，叶绿素荧光参数均明显下降.上述结果表明，高盐和低盐胁迫下，坛紫菜叶状体的光合作用受到抑制，机体通过维持较高的抗氧化酶活性以提高活性氧的清除能力，进而保证藻体的正常存活. |
| 关键词: 海洋生物学 坛紫菜 盐胁迫 抗氧化系统 光合作用参数 |
| DOI：10.3969/J.ISSN.2095-4972.2018.03.010 |
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| 基金项目:现代农业产业技术体系专项资金资助项目（CARS-50） |
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| Effect of different saline stress on physiological indexes of Pyropia haitanensis |
| XU Yan,WANG Wen-lei,XU Kai,XU Yan,JI De-hua,CHEN Chang-sheng,XIE Chao-tian |
| (College of Fisheries, Jimei University, Xiamen 361021, China) |
| Abstract: |
| The stresses of high salinity (110) and low salinity (0) on the (·OH-) content, hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, superoxide anion (O2-·) content, superoxide dismutase (SOD) activity, catalase (CAT) activity, ascorbate peroxidase (GSH) activity and chlorophyll fluorescence parameters including the maximum photochemical efficiency (Fv/Fm), apparent photosynthetic electron transport efficiency (ETR), non-photochemical fluorescence quenching (NPQ) and the actual photosynthetic efficiency［Y(II)］ of Porphyra (Pyropia haitanensis Z-61) blades were studied in order to explore the tolerance mechanism of the blades at different time (0h, 4h, 8h, 24h and 4h after restoration). The results showed that under high and low saline stresses, the content of H2O2 and ·OH-increased gradually with time, while the content of O2-· changed insignificantly after 4h stress. Compared with the high saline stress, the contents of H2O2, O2-· and ·OH-in the blades of lower saline stress were higher and the content of MDA in the membrane lipid peroxides increased significantly. It indicated that the oxidative damage of the blades was much serious than that in the high saline stress. Under 24h high saline stress, the activity of SOD reached the maximum, and the activities of CAT, APX and GSH showed an increase in the first and then decreased.Under low saline stress, the activities of SOD and GSH were increasing, respectively, and the activities of CAT and APX increased first and then decreased. In addition, the chlorophyll fluorescence parameters decreased with time under both low and high saline stress. The results showed that the photosynthesis of the blades was inhibited, and the algae ensure the normal survival by maintaining a higher antioxidant enzyme activity to improve the ability of active oxygen scavenging. |
| Key words: marine biology Pyropia haitanensis salinity stress antioxidant system photosynthesis parameters |
