Effect of carbon nanomaterials on cell toxicity, biomass production, nutritional and active compound accumulation in plants

Abstract The unique characteristics of carbon nanomaterials (CNMs) have attracted great attention in the agricultural field since the breakthrough of fullerenes, carbon nanotubes (CNTs) and graphene. Worldwide, there have been numerous efforts to insight new interactions of CNMs with plants. Published research reported contradictory effects of CNMs on plant toxicity, biomass accumulation, development stages, nutritional and pharmaceutical compound accumulation. Thus, growth and development patterns varied in different plant species and depended on the CNM types, concentration, exposure time, plant species and growth conditions on which these were applied. It was found that CNMs at low concentrations activated water channel and cell wall extension proteins which promoted water uptake, nutrient absorption, seed germination, seedling growth and photosynthesis. On the contrary, at high doses CNMs promoted free radicals and some antioxidant enzyme production which induced oxidative stress responses and cell damage. Also, CNMs stimulated the accumulation of nutritional (carotenoids) and pharmaceutical compounds in a dose-dependent manner. Researchers noted that CNMs by changing the genes involved in secondary metabolite pathways could regulate their accumulation. The present review updates the effect of various CNMs on plant toxicity, biomass accumulation, development stages, nutritional and pharmaceutical compound accumulation in plants.