Graphene-based materials do not impair physiology, gene expression and growth dynamics of the aeroterrestrial microalga Trebouxia gelatinosa
Graphene-based materials do not impair physiology, gene expression and growth dynamics of the aeroterrestrial microalga Trebouxia gelatinosa
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DOI：
10.1080/17435390.2019.1570371
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发表时间：
2019-06-21
期刊：
影响因子：
5
通讯作者：
Tretiach, Mauro
中科院分区：
文献类型：
--
作者：
Banchi, Elisa;Carniel, Fabio Candotto;Tretiach, Mauro
研究了两种石墨烯基材料（GBM）--少层石墨烯（FLG）和氧化石墨烯（GO）--在气生绿色微藻Trebouxia gelatinosa中的作用。藻类进行短期和长期暴露于GBM在0.01，1和50 μ g mL（-1）。用共聚焦显微镜、拉曼光谱和透射电镜研究了短期暴露后GBM的内化。通过分析叶绿素a荧光（Chl（a）F）、胁迫相关基因的表达和膜完整性，验证了GBM与H2 O2诱导的氧化胁迫相比的潜在负面效应。长达4周的曝光的影响进行了评估，分析生长动力学，叶绿素（a）F和光合色素。在细胞中未观察到GBM，但在细胞壁和质膜之间的界面处检测到FLG，而观察到GO粘附于外壁表面。FLG引起HSP 70 -1基因的下调，蛋白水平保持稳定，而GO没有影响。H2 O2对Chl（a）F、基因表达和HSP 70蛋白水平的影响具有剂量和时间依赖性。长期暴露于GBM没有影响生长动态，叶绿素（a）F或光合色素含量，表明观察到的少数短期影响对长期没有危险。结果表明，FLG和质膜之间的相互作用是无害的，激活HSP 70 -1基因的下调类似于H2 O2诱导。我们的工作表明，研究GBM对非模式生物的影响是重要的，因为模式绿色微藻的结果并不能代表整个分类组。
The effects of two graphene-based materials (GBMs), few-layers graphene (FLG) and graphene oxide (GO), were studied in the aeroterrestrial green microalga Trebouxia gelatinosa. Algae were subjected to short- and long-term exposure to GBMs at 0.01, 1 and 50 mu g mL (- 1). GBMs internalization after short-term exposures was investigated with confocal microscopy, Raman spectroscopy and TEM. Potential negative effects of GBMs, compared to the oxidative stress induced by H2O2, were verified by analyzing chlorophyl a fluorescence (Chl(a)F), expression of stress-related genes and membrane integrity. Effects of up to 4-week-long exposures were assessed analyzing growth dynamics, Chl(a)F and photosynthetic pigments. GBMs were not observed in cells but FLG was detected at the interface between the cell wall and plasma membrane, whereas GO was observed adherent to the external wall surface. FLG caused the down-regulation of the HSP70-1 gene, with the protein levels remaining stable, whereas GO had no effect. In comparison, H2O2 produced dose- and time-dependent effects on Chl(a)F, gene expression and HSP70 protein level. Long-term exposures to GBMs did not affect growth dynamics, Chl(a)F or photosynthetic pigment contents, indicating that the few observed short-term effects were not dangerous on the long-term. Results suggest that interactions between FLG and plasma membrane were harmless, activating a down-regulation of the HSP70-1 gene similar to that induced by H2O2. Our work shows that studying GBMs effects on non-model organisms is important since the results of model green microalgae are not representative of the whole taxonomic group.