以伪矮海链藻(Thalassiosirapseudonana)为研究对象,考察了磷化氢(PH3)对其抗氧化酶系统的影响,分析了P也对海洋微藻可能存在的作用途径。研究发现,在实验前期,随着PH,浓度的升高,单位藻细胞超氧化物歧化酶(SOD)活性、过氧化氢酶(CAT)活性随之升高,丙二醛(MDA)含量降低;而实验后期,高浓度PH,处理组S01)及CAT活性下降,MDA含量随PH,浓度的升高而升高。实验结果表明,低浓度的PH,可激活藻细胞抗氧化防御系统,增强藻细胞耐逆性;而高浓度的PH3致使细胞所受氧化压力超过抗氧化酶系统的防御能力,导致细胞损伤程度增大,该结果揭示了P也对伪矮海链藻抗氧化酶系统的双重效应。本研究结果将为深入探讨PH,对海洋微藻的作用机制提供科学依据,对进一步揭示海水体系中磷(P)的生物学及生态学意义具有重要作用。
In the present study, the effects of phosphine on the antioxidant enzyme system in Thalassiosira pseudonana were studied, and a possible function of phosphine on microalgae was analyzed. The results showed that the activity of SOD ( superoxide dismutase) and CAT (catalase) increased with increasing phosphine concentration, and the content of MDA (malonyldialdehyde) decreased with the increasing concentration of phosphine during the early culture period. During the decline phase, high phosphine concentrations had inhibitory effects on SOD and CAT, and the content of MDA increased with increasing phosphine concentration. These results indica ted that low phosphine concentrations could enhance antioxidant defense system and ease the damage of membrane lipid peroxidation. However, high phosphine concentrations would induce too much oxidative stress on the antioxidant enzyme system, resulting in lipid peroxidatiou. The changes of SOD, CAT and MDA indicated the dual effects of phosphine on antioxidant system of T. pseudonana. This work will provide a basis for studying the mechanism of effect of phosphine on marine microalgae, and it will be helpful for further re search on the biological and ecological significance of phosphorus in the ocean environment.