The Ecotoxicology Of Bisphenol A On Three Aquatic Plants

BPA?Bisphenol A?is a typical environmental endocrine disruptor chemical.It is harmful to the normal physiological processes of organisms,which can affect the endocrine system,nervous system,reproductive system and immune system.Tremendous BPA have get into the aquatic environment after its high consumption and caused the potential toxicological impact on aquatic plants.In this study,three aquatic plants?Spirodela polyrrhiza,Lemna minor,and Azolla filiculoides?were chosen to investigate the ecotoxicological effects of BPA on growth,photosynthesis pigments,oxidative damage,anti-oxidant system and osmoregulation substances of aquatic plants with different BPA concentrations.The data are promised to provide theoretical basis for exploring the defense mechanism of the aquatic plants against BPA,and the results are as follows:1.Compared with the control group,the fresh weight of the S.polyrrhiza increased first and decreased as the BPA concentration increased.The fresh weight was significantly higher at 20 mg/L and lower at 50 mg/L.Contents of Chl a and total Chlorophyll increased at 1,5 and 20 mg/L,and Chl b elevated significantly at 1 and 5 mg/L.The activities of anti-superoxide anion free radical of all BPA treatment groups were significantly lower than which of the control group;and decreased as the BPA concentration increased.Compared with the control group,the concentration of H₂O₂decreased significantly at 5,20 and 50 mg/L,and the MDA content significantly increased at 20 and 50 mg/L,furthermore,the activities of CAT,GR,and SOD were significantly reduced in all BPA exposed groups.POD activity significantly dropped at 5,20,and 50 mg/L,and total antioxidant capacity decreased significantly at 20 and 50 mg/L,and APX activity of treatment groups were lower than which of the control group,but there was no significant difference.GSH content improved significantly at 5,20 and 50mg/L.The soluble sugar content significantly increased at 20 mg/L,and the soluble protein content significantly increased at 5,20,and 50 mg/L.2.Compared with the control group,the fresh weight of the L.minor increased first and then decreased as the BPA concentrations increased;there was significant improvement at5 mg/L and significant reduction at 50 mg/L.The photosynthetic pigments showed the same trend as the fresh weight.Contents of Chl a,Chl b and total Chlorophyll increased significantly at 5 and 20 mg/L,and decreased significantly at 50 mg/L.The H₂O₂ content dropped significantly at 5 mg/L and elevated clearly at 50 mg/L.The activity of anti-superoxide anion free radical significantly decreased at 1,5,20 mg/L,and there was significant improvement at 50 mg/L.The inhibitory hydroxyl radical activity of all the BPA treatment groups reduced as the concentrations increased,which were all lower than the control group.The MDA content increased significantly in all BPA treatment groups.The POD,GR and T-AOC of the BPA treatment groups were significantly higher than which of the control group.The APX activity increased as the BPA concentration increased,and improved significantly at 20 and 50 mg/L.The CAT activity decreased first and then increased,which significantly decreased at 5 mg/L and significantly increased at50 mg/L.SOD activity decreased significantly at 1,5 and 20 mg/L,and increased significantly at 50 mg/L.The GSH content decreased first and then increased,which significantly reduced at 5 mg/L and significantly increased at 50 mg/L.The proline content significantly decreased at 1,5 mg/L,and significantly increased at 50 mg/L.The soluble protein significantly increased at 20 mg/L,and significantly decreased at 50 mg/L.The soluble sugar contents increased significantly at 5 and 20 mg/L.3.The fresh weight of A.filiculoides increased first and then decreased as the BPA concentrations increased,which significantly increased at 5 mg/L and decreased at 50mg/L.Contents of Chl a,Chl b and total Chlorophyll increased significantly at 20 mg/L,and Chl a reducued clearly at 50 mg/L.The H₂O₂ concentration decreased significantly at5 mg/L,and improved clearly at 50 mg/L.The activity of hydroxyl radical inhibition was lower significantly in all BPA treatment groups than which of the control group,and dropped gradually as the BPA concentrations increased.The MDA content significantly increased at 1 and 5 mg/L.The activity of CAT and SOD in all BPA treatment groups was significantly lower than which of the control group.GR activity significantly decreased at5 and 20 mg/L.POD activity significantly increased at 1 mg/L,and APX activity significantly increased at 50 mg/L.T-AOC significantly decreased at 1,5,20 mg/L,and significantly increased at 50 mg/L.The GSH content significantly decreased at 1,5 mg/L and increased clearly at 50 mg/L.The proline content of all BPA treatment groups was significantly lower than which of the control group.The soluble protein content significantly increased at 1 and 5 mg/L and the soluble sugar content was significantly improved at 5 mg/L.In summary,low-concentration of BPA caused increment the the photosynthetic pigment contents of three aquatic plants,and promoted the accumulation of organic materials,and thus the fresh weight gradually increased.As the BPA concentrations elevated continuously,the photosynthetic pigment contents decreased,and photosynthesis decreased,and thus the accumulations of the organic materials decreased.At the same time,the reactive oxygen species accumulated,which led to the oxidative damage and the membrane lipid peroxidation occurred.As the results,the anti-oxidant system started to play the role of defense and osmoregulation substances were influenced and resulted in the inhibition of the growth of three aquatic plants.