中国水产科学2017，Vol.24Issue(4)：766-773,8.DOI:10.3724/SP.J.1118.2017.16356
Hg2+和Pb2+胁迫对脆江蓠生长及光合生理的影响
Effects of Hg2+ and Pb2+ on the growth and photosynthetic physiological characteristics of Gracilaria chouae
摘要
Abstract
In this study, we investigated the impact of Hg2+ and Pb2+ on the growth and photosynthetic physiologi-cal characteristics of Gracilaria chouae by exposing algal thalli to five concentrations of HgCl2 (0.01 mg/L, 0.025 mg/L, 0.05 mg/L, 0.1 mg/L, 0.25 mg/L, and 0.5 mg/L) and PbCl2 (0.05 mg/L, 0.1 mg/L, 0.5 mg/L, 1.0 mg/L, 2.0 mg/L, and 4.0 mg/L); the reference group exposed to seawater without Hg2+ and Pb2+. The growth rate, photosynthetic rate, pigment content, chlorophyll II fluorescence characteristics, and the activity of RuBisCO and PPDK in the thalli were measured after 7 days of incubation. The special growth rate (SGR) reduced significantly as the Hg2+level increased (P<0.05), mortality was observed following incubation with the highest concentration of Hg2+, and the photosynthetic rate reduced by 35.48%–77.50%. Similar trends were also observed for chlorophyll a (Chla) and carotenoid (Car) levels (P<0.05). Phycoerythrin (PE) and phycocyanin (PC) content was significantly lower at Hg2+ levels above 0.1 mg/L (P<0.05). The trend of the variation of Fv/Fm and Y( Ⅱ)with Hg2+ concentration was close to a bimodal curve, and the second peak appeared at 0.05 mg/L;PPDK activity showed a similar trend. The specific growth rate and Chla and Car content was significantly lower at Pb2+ levels above 1 mg/L (P<0.05). However, no significant change in either chlorophyll Ⅱ fluorescence characteristics or the level in PC content was found among different Pb2+ levels. Significantly lower RuBisCO activity was found at the highest Pb2+concentration than at lower concentrations, while PPDK activity was significantly higher (P<0.05). In con-clusion, Hg2+ and Pb2+ both showed detrimental effects on the growth and photosynthesis of G. chouae; however, this alga is more susceptible to Hg2+. A stress response was observed after the Hg2+concentration reached 0.01 mg/L, and this response increased as Hg2+concentration increased, while no stress response was observed at Pb2+concentrations below 1 mg/L.关键词
脆江蓠/Hg2+/Pb2+/光合生理Key words
Gracilaria chouae/Hg2+/Pb2+/photosynthetic physiological characteristics分类
农业科技引用本文复制引用
陈琼琳,李加琦,姜娓娓,薛素燕,李阳,沈淑芳,卞大鹏,方建光,毛玉泽..Hg2+和Pb2+胁迫对脆江蓠生长及光合生理的影响[J].中国水产科学,2017,24(4):766-773,8.基金项目
国家自然科学基金项目(41676147) （41676147）
国家自然基金委员会-山东省联合资助项目(U1606404) （U1606404）
中国水产科学研究院基本科研业务费项目(2017HY-8D0608). （2017HY-8D0608）
