Division of Life Science, University of Incheon, Incheon 406-840, Republic of Korea.
Aquat Toxicol. 2012 Jan 15;106-107:182-8. doi: 10.1016/j.aquatox.2011.10.004. Epub 2011 Nov 4.
Phenol is a ubiquitous environmental pollutant and a widely used reference toxicant for many bioassays. However, little information is available regarding the toxic effects of phenol on aquatic macrophytes. Seventy-two hour bioassays, with different end-points, were carried out to assess phenol toxicity in Lemna paucicostata. A concentration-dependent decline in frond multiplication and colony disintegration was observed, with 11.38 and 22.76 μM phenol resulting in browning of fronds and colony disintegration, respectively. Growth of fronds, as measured by changes in surface area, was significantly inhibited with EC₅₀ value of 2.70 μM. When pulse amplitude modulated chlorophyll a (Chl a) fluorescence imaging (i-PAM) was employed, the maximum quantum yield of PS II (F(v)/F(m)) significantly declined with increasing phenol concentrations with resultant EC₅₀ of 1.91 μM and coefficients of variation (CVs) generated for the EC₅₀ values of less than 4.7%. A gradual increase in fluorescence emissions from chlorophylls a and b and pheophytin up to a concentration of 2.85 μM was found but declined markedly at higher concentrations. The significant correlation between the F(v)/F(m) and surface growth rate data implies that the former is an appropriate biomarker of whole plant toxicity. Using imaging Chl a fluorescence on L. paucicostata provides a rapid, sensitive and reliable method for assessing the toxic risks posed by phenol to aquatic ecosystems and has practical applications for municipal and industrial waste water management.
苯酚是一种普遍存在的环境污染物，也是许多生物测定中广泛使用的参考毒物。然而，关于苯酚对水生植物的毒性影响的信息却很少。我们进行了 72 小时的生物测定，使用不同的终点来评估苯酚对浮萍的毒性。观察到叶片繁殖和群体解体的浓度依赖性下降，11.38 和 22.76 μM 的苯酚分别导致叶片变褐和群体解体。用表面积变化来衡量的叶片生长，随着 EC₅₀ 值为 2.70 μM 而受到显著抑制。当采用脉冲振幅调制叶绿素 a（Chl a）荧光成像（i-PAM）时，随着苯酚浓度的增加，PS II 的最大量子产率（F(v)/F(m)）显著下降，结果 EC₅₀值为 1.91 μM，而 EC₅₀值的变异系数（CVs）小于 4.7%。发现叶绿素 a 和 b 以及脱镁叶绿素的荧光发射逐渐增加，直到 2.85 μM，但在更高浓度下显著下降。F(v)/F(m)和表面生长速率数据之间的显著相关性表明，前者是整个植物毒性的合适生物标志物。使用浮萍的成像 Chl a 荧光可以快速、灵敏和可靠地评估苯酚对水生生态系统造成的毒性风险，并且在城市和工业废水管理中有实际应用。
