Interaction of carbon nanohorns with plants: Uptake and biological effects

Abstract

Single-Walled Carbon Nanohorns (SWCNHs) are a unique carbon-based nanomaterial with promising application in different fields including, medicine, genetic engineering and horticulture. Here, we investigated the biological response of six crop species (barley, corn, rice, soybean, switchgrass, tomato) and tobacco cell culture to the exposure of SWCNHs. We found that SWCNHs can activate seed germination of selected crops and enhance growth of different organs of corn, tomato, rice and soybean. At cellular level, growth of tobacco cells was increased in response to exposure of SWCNHs (78% increase compared to control). Uptake of SWCNHs by exposed crops and tobacco cells was confirmed by transmission electron microscopy (TEM) and quantified by microwave induced heating (MIH) technique. At genetic level, SWCNHs were able to affect expression of a number of tomato genes that are involved in stress responses, cellular responses and metabolic processes. We have concluded that SWCNHs can be used as plant growth regulators and have the potential for plant-related applications.

Multi-walled carbon nanotubes stimulate callus induction, secondary metabolites biosynthesis and antioxidant capacity in medicinal plant Satureja khuzestanica grown in vitro

“…Due to their unique characteristics including surface chemistry, type of attachments and biocompability [31], carbon nanomaterials are considered as a promising candidate for modulating the redox status and modifying the physiological processes in plants exposed to such materials. The ability of carbon nanotubes to enhance the callus growth could be explained by their physical characteristics [32]. Moreover, the plant growth promotion following carbon nanotubes treatment has been attributed to the specific type and charge of functional groups on the surface, and the aggregation level of nanomaterials applied [5].…”

“…However, there is evidence that application of MWCNTs in a wide range of doses (5-500 lg ml À1 ) increase cell growth (by 55-64% over control) of tobacco callus culture [4]. Also, single-walled carbon nanohorn (at 100 lg ml À1 ) has been reported to increase the growth of tobacco callus up to 78% [32]. Values are given as mean ± SD, (n = 3).…”

“…Carbon-based nanomaterials interact with the cell wall through adhesion forces including hydrogen bonding between components of cell wall (e.g., nitrogen containing groups) and nanotubes [35] and then they envelop to the surface of cells and form clusters with filamentous structures and penetrate plant cell wall [32], leading to change in metabolic functions as well. Exposure of plant cell culture to different types of elicitors (biotic and abiotic) can stimulate the biosynthesis of secondary metabolites [48].…”

Carbon nanotubes: Impacts and behaviour in the terrestrial ecosystem - A review

“…Moreover, short MWCNTs (<100 nm) were targeted to specific cellular sub-structures such as nucleus, plastids and vacuoles. Serag et al [100] also reviewed that CNTs can penetrate plant cell walls, target specific organelles, probe protein-carrier activity and induce (Table 3): CNTs increased seed germination on a large range of concentrations (i.e: 40; 50; 100 and 500 mg/L) [21,88,89,103,104]. They can increase plant growth with a higher biomass production, higher flower production, or enhanced root elongation [86,89,91,94,96,103e109].…”

“…[104] Soybean hybrid S42-T4 (Glycine maxI), barley hybrid Robust (continued on next page) / Isolated CNTs were observed inside cells as a result of a direct penetration of the plasma membrane.…”