| 摘要: |
| 研究了杜氏盐藻Dunaliella salina 在不同浓度的Cu2+、Zn2+、Cd2+等重金属离子胁迫一段时间(24、48、72 和96 h)后, 叶绿素荧光特性的变化情况。测定的主要参数有: PSII 的最大光能转化效率（Fv/Fm)、PSII 的潜在活性(Fv/Fo)、PSII 的实际光能转化效率(Yield)、相对光合电子传递效率(rETR)、光化学淬灭(qP)和非光化学淬灭(NPQ)。研究结果表明, 当Cu2+浓度范围在600～800 μmol/L 时, 杜氏盐藻的Fv/Fm、Fv/Fo、Yield、rETR 和qP 均明显降低, NPQ 变化不规律, 随着胁迫时间的延长, 除qP 在96 h时有所上升外, 各荧光参数均逐渐降低; Zn2+胁迫下Fv/Fm、Fv/Fo、Yield 和rETR 随着浓度的增加而降低, NPQ 先下降后上升, qP 仅在Zn2+浓度范围(800～3200 μmol/L)下明显下降, 随着胁迫时间的延长, 各荧光参数均逐渐降低; Cd2+胁迫下各荧光参数均明显下降, 随着胁迫时间的延长, Fv/Fm、Fv/Fo 和NPQ先下降后上升, 在48 h 时达到最低值, Yield、rETR 和qP 均逐渐降低。在3 种重金属离子胁迫下, 细胞密度和叶绿素相对含量也显著降低。根据3 种重金属离子的半抑制浓度(EC50), 其毒性大小顺序为Cu2+ >Cd2+ > Zn2+。 |
| 关键词: 杜氏盐藻Dunaliella salina 重金属胁迫 叶绿素荧光 |
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| 基金项目:?“十一五”国家科技支撑计划项目(2006BAD09A03); 中国海洋大学海水养殖教育部重点实验室开放课题(200603) |
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| Effects of heavy metal exposure on the growth and chlorophyll fluorescence of Dunaliella salina |
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WANG Shuai,LIANG Ying,FENG Li-xia,TIAN Chuan-yuan
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| Abstract: |
| The modulate chlorophyll fluorescence kinetics of Dunaliella salina under different concentrations of heavy metals (Cu2+, Zn2+, Cd2+) and different durations (24, 48, 72 and 96 h) were investigated. The main parameters determined in the present study included the maximal photochemical efficiency of PSII (Fv/Fm), the potential activity of PSII (Fv/Fo), the actual photochemical efficiency of PSII in the light (Yield), the relative electron transport rate (rETR), the photochemical quenching (qP), and the non-photochemical quenching (NPQ). The results showed that the parameters of D. salina Fv/Fm, Fv/Fo, Yield, rETR and qP reduced markedly at 600～800 μmol/L by Cu2+, NPQ first decreased then increased, and declined at 400 μmol/L again. The changed degree of the parameters all reduced with the increasing exposure time except qP rose at 96 h;Fv/Fm, Fv/Fo, Yield and rETR reduced under toxic effect by Zn2+, NPQ first decreased then increased, qP declined clearly just at 800～3200 μmol/L by Zn2+, the parameters all decreased with the increasing exposure time; all of the parameters reduced under toxic effect by Cd2+, Fv/Fm, Fv/Fo and NPQ first decreased then increased with the increasing exposure time, the data reach to the lowest at 48 h, Yield, rETR and qP decreased all the time. The cell density and chlorophyll content were also decreased under heavy metal stress. The EC50 values indicated that the toxicities followed the order of Cu2+ >Cd2+ >Zn2+. |
| Key words: Dunaliella salina heavy metal stress chlorophyll fluorescence |
