Gramine-induced growth inhibition, oxidative damage and antioxidant responses in freshwater cyanobacterium Microcystis aeruginosa
Gramine-induced growth inhibition, oxidative damage and antioxidant responses in freshwater cyanobacterium Microcystis aeruginosa
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DOI：
10.1016/j.aquatox.2008.11.014
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发表时间：
2009-02-19
影响因子：
4.5
通讯作者：
Li, Feng-Min
中科院分区：
文献类型：
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作者：
Hong, Yu;Hu, Hong-Ying;Li, Feng-Min
近年来，探索和开发防治藻华特别是铜绿微囊藻藻华的有效方法已成为水环境保护领域的一个重要课题。化感化学物质（天然植物毒素）被认为是控制藻华的有前途的杀藻剂来源。本研究的目的是确定一种众所周知的化感化学物gramine （N，N-二甲基-3-氨基甲基吲哚）对绿藻M. aeruginosa的抑制作用及其潜在机制。结果表明，该吲哚类生物碱能有效抑制铜绿假单胞菌的生长。随着初始藻密度（IAD）的增加，3d抑制50%的有效浓度（EC50,3d）增加。当IAD由5 × 10(4)增加到5 × 105 cells mL（-1）时，EC50, 3d由0.5 mg L-1增加到2.1 mg L-1。在M. aeruginosa细胞中，gramine引起活性氧（ROS）水平明显升高。在谷物处理的细胞中，脂质过氧化产物丙二醛（MDA）显著增加。谷氨酰胺对酶促抗氧化剂和非酶促抗氧化剂的作用方式不同。超氧化物歧化酶（SOD）活性降低。过氧化氢酶（CAT）活性在4 h后升高，60 h后下降，抗坏血酸（AsA）和还原性谷胱甘肽（GSH）含量和再生速率在4 h后均升高。暴露40 h后，仅GSH含量增加。这些结果表明，绿脓杆菌抗氧化剂的激活在初期抵抗gramine胁迫中起着重要作用，SOD的失活是gramine抑制M. aeruginosa生长的关键，gramine对M. aeruginosa的植物毒性可能是由于ROS氧化引起的氧化损伤。(C) 2008 Elsevier B.V.版权所有
In recent years, the exploration and development of the effective methods of treatment and prevention to algal blooms, especially Microcystis aeruginosa blooms has been an important issue in the field of water environment protection. Allelochemicals (natural plant toxins) are considered promising sources of algicides to control algal blooms. The objective of this study is to determine the inhibitory effects and potential mechanisms of a well-known allelochemical gramine (N,N-dimethyl-3-amino-methylindole) on bloom-forming cyanobacterium M. aeruginosa. The results showed that this indole alkaloid effectively inhibited the growth of M. aeruginosa. The effective concentration causing a 50% inhibition at 3 d (EC50,3d) increased with the initial algal density (IAD) increasing. When IAD increased from 5 x 10(4) to 5 x 105 cells mL(-1), the values of EC50, 3d increased from 0.5 to 2.1 mg L-1. In the cells of M. aeruginosa, gramine caused an obvious increase in the level of reactive oxygen species (ROS). The lipid-peroxidation product malondialdehyde (MDA) increased significantly in gramine-treated cells. The effects of gramine on enzymatic and non-enzymatic antioxidants were in different manners. The activity of superoxide dismutase (SOD) was decreased after gramine exposure. The catalase (CAT) activity was increased after 4 h but decreased from 60 h. Both the contents and the regeneration rates of ascorbic acid (AsA) and reduced glutathione (GSH) were increased after 4 h of exposure to gramine. However, only GSH content was still increased after 40 h of exposure. These results suggested that the activation of antioxidants in M. aeruginosa played an important role to resist the stress from gramine at initial time, the inactivation of SOD is crucial to the growth inhibition of M. aeruginosa by gramine, and the phytotoxicity of gramine on M. aeruginosa may be due to oxidative damage via oxidation of ROS. (C) 2008 Elsevier B.V. All rights reserved.