Green tides have occurred every year from 2007 to 2014 in the Yellow Sea. Ulva prolifera （Mtiller） J. Agardh has been identified as the bloom-forming alga, co-occurring with U. intestinalis. We observed distinct str...Green tides have occurred every year from 2007 to 2014 in the Yellow Sea. Ulva prolifera （Mtiller） J. Agardh has been identified as the bloom-forming alga, co-occurring with U. intestinalis. We observed distinct strategies for both algal species during green tides. U.prolifera exhibited a high abundance initially and then decreased dramatically, while U. intestinalis persisted throughout. The antioxidant system responses of these two macroalgae were compared in the late phase of a green tide （in-situ） and after laboratory acclimation. Lipid peroxidation and antioxidant system responses differed significantly between the two. Malondialdehyde and hydrogen peroxide contents increased significantly in-situ in U. prolifera, but not in U. intestinalis. In U. prolifera, we observed a significant decrease in total antioxidant ability （T-AOC）, antioxidant enzymes （SOD and Apx）, and non-enzyme antioxidants （GSH and AsA） in-situ. U. intestinalis showed the same pattern of T-AOC and SOD, but its Gpx, Apx, and GSH responses did not differ significantly. The results suggest that U. prolifera was more susceptible than U. intestinalis to the harsh environmental changes during the late phase of a Yellow Sea green tide. The boom and bust strategy exhibited by U. prolifera and the persistence of U. intestinalis can be explained by differences in enzyme activity and antioxidant systems.展开更多
基金Supported by the China Postdoctoral Science Foundation(No.2013M531648)the Natural Science Foundation of Shandong Province(No.ZR2014DP008)+2 种基金the Fundamental Research Funds for the Central Universities(No.201513046)the National Special Research Fund for Non-Profit Marine Sector(No.201305009)the Joint Funds of the National Natural Science Foundation of China(No.U1406403)
文摘Green tides have occurred every year from 2007 to 2014 in the Yellow Sea. Ulva prolifera （Mtiller） J. Agardh has been identified as the bloom-forming alga, co-occurring with U. intestinalis. We observed distinct strategies for both algal species during green tides. U.prolifera exhibited a high abundance initially and then decreased dramatically, while U. intestinalis persisted throughout. The antioxidant system responses of these two macroalgae were compared in the late phase of a green tide （in-situ） and after laboratory acclimation. Lipid peroxidation and antioxidant system responses differed significantly between the two. Malondialdehyde and hydrogen peroxide contents increased significantly in-situ in U. prolifera, but not in U. intestinalis. In U. prolifera, we observed a significant decrease in total antioxidant ability （T-AOC）, antioxidant enzymes （SOD and Apx）, and non-enzyme antioxidants （GSH and AsA） in-situ. U. intestinalis showed the same pattern of T-AOC and SOD, but its Gpx, Apx, and GSH responses did not differ significantly. The results suggest that U. prolifera was more susceptible than U. intestinalis to the harsh environmental changes during the late phase of a Yellow Sea green tide. The boom and bust strategy exhibited by U. prolifera and the persistence of U. intestinalis can be explained by differences in enzyme activity and antioxidant systems.
