Nicotine uptake by peppermint plants as a possible source of nicotine in plant-derived products

Abstract

Recently, nicotine has been detected in a large number of food crops and plant-derived products such as spices and herbal teas, but the origin of this nicotine is unknown. This study aimed to elucidate the putative sources of nicotine. We investigate the uptake of nicotine from nicotine-contaminated soils and tobacco smoke using peppermint plants, Mentha × piperita, as a model system in mulching and fumigation experiments. Results show that all the peppermint plants contain minor amounts of nicotine before treatment, but the experiments revealed that the plants also incorporate nicotine considerably from the soil as well as from tobacco smoke. These findings demonstrate for the first time that the reported occurrence of nicotine indeed may originate from tobacco. The incorporated nicotine was subsequently metabolised by the plants. Apart from the nutritional aspects, the results on nicotine uptake may also affect basic plant biology, because they demonstrate that alkaloids can be transferred from one plant, after its death, to another plant species.