Single Walled Carbon Nanotubes Exhibit Dual-Phase Regulation to Exposed Arabidopsis Mesophyll Cells

Abstract

Herein we are the first to report that single-walled carbon nanotubes (SWCNTs) exhibit dual-phase regulation to Arabidopsis mesophyll cells exposed to different concentration of SWCNTs. The mesophyll protoplasts were prepared by enzyme digestion, and incubated with 15, 25, 50, 100 μg/ml SWCNTs for 48 h, and then were observed by optical microscopy and transmission electron microscopy, the reactive oxygen species (ROS) generation was measured. Partial protoplasts were stained with propidium iodide and 4'-6- diamidino-2-phenylindole, partial protoplasts were incubated with fluorescein isothiocyanate-labeled SWCNTs, and observed by fluorescence microscopy. Results showed that SWCNTs could traverse both the plant cell wall and cell membrane, with less than or equal to 50 μg/ml in the culture medium, SWCNTs stimulated plant cells to grow out trichome clusters on their surface, with more than 50 μg/ml SWCNTs in the culture medium, SWCNTs exhibited obvious toxic effects to the protoplasts such as increasing generation of ROS, inducing changes of protoplast morphology, changing green leaves into yellow, and inducing protoplast cells' necrosis and apoptosis. In conclusion, single walled carbon nanotubes can get through Arabidopsis mesophyll cell wall and membrane, and exhibit dose-dependent dual-phase regulation to Arabidopsis mesophyll protoplasts such as low dose stimulating cell growth, and high dose inducing cells' ROS generation, necrosis or apoptosis.

Physiological effect of graphene oxide on tobacco BY-2 suspension cells and its immigration

“…While cell vitality exhibited a steady decrease during the first four days in the higher concentrations of GO (100 and 200 μg/mL) and then had a tendency to slow down after the fourth day. The similar results were also observed in the research of carbon nanotubes [12,13]. To the best of our knowledge, it is the first research reported that GO can also stimulate plant cells growth in the lower concentration.…”

Influence of water soluble carbon dots on the growth of wheat plant

“…Tan et al (2009) demonstrated the use of MWCNT to increase reactive oxygen species (ROS) and decrease the cell viability of rice plant. Yuan et al (2011) found that SWNT (50 lg/ml) stimulate the growth of mesophyll cells of Arabidopsis. Khodakovskaya et al (2013a, b) studied at cellular level and showed the positive effect of MWCNT and explained the mechanism for the plant growth in tobacco cells.…”

“…Over last few years, there have been extensive studies to understand the influence of nanomaterials on the growth of different types of plants (Khodakovskaya et al 2009;Khodakovskaya et al 2013a, b;Lu et al 2002;Cañas et al 2008;Yang et al 2006;Hong et al 2005a, b;Tan et al 2009;Yuan et al 2011;Khodakovskaya et al 2013a, b;Mahajan et al 2011;Wang et al 2012;Larue et al 2012;Miralles et al 2012;Feizi et al 2012;Tripathi et al 2011;Sonkar et al 2012). Khodakovskaya et al (2009Khodakovskaya et al ( , 2013a demonstrated that at very low doses MWCNT can penetrate the seed coat and enhance the germination of tomato plant.…”

Effects of CdSe/ZnS quantum dots covered multi-walled carbon nanotubes on murine embryonicstem cells

“…Considering oxidative stress as a dominant mechanism underlying the experimentally observed ES cell cytotoxicity after exposure and internalization of high doses of FMNTs, we could speculate that low doses of FMNTs generate a few reactive oxygen species acting as regulators of cell differentiation. Molecular evidence for such a hypothesis was recently reported by Spike and Macleod [27][28][29][30][31][32], who identified the pRb tumor suppressor pathway as a critical cell cycle regulator of hematopoietic hemostasis at the G2/M checkpoint under oxidative stress. Future studies are required to define the molecular consequences Figure 4 Effect of FMNTs on the differentiation of embryonic stem cells.…”

“…Alternatively, internalized FMNTs may stimulate cell metabolism enzymes associated with endosomal/lysosomal degradation pathways. Formation of free radicals increases oxidative stress leading to structural modifications of vital cellular components, including DNA, RNA, and proteins, that ultimately induce necrosis and cell apoptosis [26][27][28][29].…”