双酚A对紫背浮萍生长和光合色素及抗氧化系统影响

以紫背浮萍为实验对象,探究双酚A(bsiphenol A, BPA)对其生长、光合色素含量、抗氧化系统和渗透压调节物质的影响。结果表明,不同浓度(0、1、5、20和50 mg·L~(-1))BPA连续暴露7 d后,与对照组相比,随暴露浓度升高,紫背浮萍湿重和叶绿素含量呈现先显著增加后降低的趋势;暴露组过氧化氢(H_2O_2)含量和抗超氧阴离子自由基活性显著降低;丙二醛(MDA)含量在20和50 mg·L~(-1)组显著升高;暴露组抗氧化酶活性包括超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)和总抗氧化能力(T-AOC)均低于对照组;谷胱甘肽(GSH)含量在高浓度组显著升高,20 mg·L~(-1)组可溶性糖含量显著升高,可溶性蛋白含量在中高浓度组显著增加。研究表明,中低浓度BPA会提高紫背浮萍光合色素含量,有机物积累增多,促进其生长;但随BPA浓度不断升高,紫背浮萍体内产生氧化损伤,抗氧化酶活性及叶绿素含量降低,生长受到抑制。本研究结果将为BPA污染控制及对水生植物生态毒性效应评价提供理论基础。

Effects of Bisphenol A on Growth, Photosynthesis Pigment and Antioxidant System of Spirodela polyrrhiza

In order to investigate the ecotoxicity effects of bispehnol A (BPA), Spirodela polyrrhiza were utilized for growth, photosynthetic pigment contents, antioxidant system and osmotic pressure regulator tests. The results showed that the fresh weight and photosynthetic pigment contents increased and then decreased as the BPA concentration increased. The H₂O₂ content and anti-superoxide anion activity in BPA treatment groups reduced significantly compared with the control group, and the malondialdehyde (MDA) levels increased in 20 and 50 mg L^-1 groups. The antioxidant enzyme, i.e., superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), aseorbateperoxidase (APX), glutathione reductase (GR), activities and total antioxidant capacity (T-AOC) decreased after BPA exposure, while the glutathione (GSH), soluble sugar and protein contents were significantly elevated by BPA. The results indicated that low and medium concentration BPA promoted the photosynthetic pigment contents and the organic material accumulated, which boosted the growth. As the BPA concentration was high, the oxidative damage occurred and the antioxidant enzymes as well as the photosynthetic pigment contents, were reduced, which led the inhibition of the growth. The findings of this study are expected to provide theoretical basis for BPA pollution control and ecotoxicological mechanism of BPA on aquatic plants.