当前位置: X-MOL 学术Aquat. Toxicol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Diclofenac and atrazine restrict the growth of a synchronous Chlamydomonas reinhardtii population via various mechanisms
Aquatic Toxicology ( IF 4.5 ) Pub Date : 2020-11-23 , DOI: 10.1016/j.aquatox.2020.105698
Darya Harshkova , Monika Majewska , Wojciech Pokora , Agnieszka Baścik-Remisiewicz , Szymon Tułodziecki , Anna Aksmann

Non-steroidal anti-inflammatory drug diclofenac (DCF) is commonly found in freshwater bodies and can have adverse effects on non-target organisms. Among the studies on DCF toxicity, several ones have reported its harmful effects on plants and algae. To gain a better understanding of the mechanisms of DCF toxicity towards green algae, we used a synchronous Chlamydomonas reinhardtii cc-1690 culture and compared DCF (135 mg/L) effects with effects caused by atrazine (ATR; 77.6 μg/L), an herbicide with a well-known mechanism of toxic action. To achieve our goal, cell number and size, photosynthetic oxygen consumption/evolution, chlorophyll a fluorescence in vivo, H2O2 production by the cells, antioxidative enzymes encoding genes expression were analyzed during light phase of the cell cycle.

We have found, that DCF and ATR affect C. reinhardtii through different mechanisms. ATR inhibited the photosynthetic electron transport chain and induced oxidative stress in chloroplast. Such chloroplastic energetics disruption indirectly influenced respiration, the intensification of which could partially mitigate low efficiency of photosynthetic energy production. As a result, ATR inhibited the growth of single cell leading to limitation in C. reinhardtii population development. In contrast to ATR-treated algae, in DCF-treated cells the fraction of active PSII reaction centers was diminished without drastic changes in electron transport or oxidative stress symptoms in chloroplast. However, significant increase in transcript level of gene encoding for mitochondria-located catalase indicates respiratory processes as a source of H2O2 overproduced in the DCF-treated cells. Because the single cell growth was not strongly affected by DCF, its adverse effect on progeny cell number seemed to be related rather to arresting of cell divisions. Concluding, although the DCF phytotoxic action appeared to be different from the action of the typical herbicide ATR, it can act as algal growth-inhibiting factor in the environment.



中文翻译:

双氯芬酸和at去津通过多种机制限制了莱茵衣藻同步种群的生长

非甾体类抗炎药双氯芬酸(DCF)通常在淡水体内发现,可能对非目标生物产生不利影响。在DCF毒性研究中,有几项报道了其对植物和藻类的有害作用。为了更好地了解DCF对绿藻的毒性作用机理,我们使用了莱茵衣藻cc-1690同步培养,并将DCF(135 mg / L)的作用与阿特拉津(ATR; 77.6μg/ L),具有众所周知的毒性作用机理的除草剂。为了实现我们的目标,细胞数量和大小,光合耗氧/进化,体内叶绿素a荧光,H 2 O 2 由细胞产生,在细胞周期的轻度阶段分析编码基因表达的抗氧化酶。

我们发现,DCF和ATR通过不同的机制影响莱茵衣藻。ATR抑制了叶绿体中的光合电子传输链并诱导了氧化应激。这种叶绿素能高能的破坏间接地影响了呼吸,其增强可以部分减轻光合能量产生的低效率。结果,ATR抑制了单细胞的生长,从而导致莱茵衣藻的限制人口发展。与ATR处理的藻类相反,在DCF处理的细胞中,活性PSII反应中心的比例减少了,而叶绿体中的电子传递或氧化应激症状却没有急剧变化。但是,编码线粒体过氧化氢酶的基因的转录水平显着增加,表明呼吸过程是DCF处理细胞中过量产生的H 2 O 2的来源。因为单细胞生长不受DCF强烈影响,所以它对子代细胞数量的不利影响似乎与阻止细胞分裂有关。结论,尽管DCF的植物毒性作用似乎不同于典型除草剂ATR的作用,但它可以作为环境中藻类生长的抑制因子。

更新日期:2020-12-09
down
wechat
bug