Environmental risk assessment of carbon nanomaterials used as plant growth regulators

For the first goal, we propose to determine whether the uptake of carbon-based nanotubes (CNTs) by plant organs can significantly affect the metabolome of exposed tomato plants. Based on our preliminary data of gene expression profiling, we propose that the absorption of CNTs by tomato plants will affect individual branches of plant metabolism but will not lead to a significant increase of potentially toxic tomato metabolites. We are going to correlate metabolomics studies with an assessment of nanoparticle uptake using a new, advanced technique of CNT measurement, MIH. The documented effect of accelerating germination and plant growth by using carbon-based nanomaterials (Khodakovskaya et al., 2011; Lahiani et al., 2016) could offer enhanced options for a number of valuable applications, from agricultural crops to biofuel crops and space-grown plants. However, risks of food chain contamination by CNTs must be assessed. Thus, the second goal of the project is to evaluate the potential toxicity of tomato fruits/leaves with accumulated CNTs using a mouse model. We hypothesize that manmade CNTs will not have significant negative effects to animals (mice) at the low doses that can be accumulated in plant organs during the application of CNTs as plant growth regulators. Toxicological experiments with CNT-contaminated tomato fruits are essential to understand the consequences of intentional or unintentional incorporation of carbon-based nanomaterials into the food chain.