Cytotoxicity of tea tree oil in tobacco cells

This study analyzed the effects of essential oil from Melaleuca alternifolia (tea tree oil) on tobacco Bright Yellow 2 cells to understand the cytological basis for its allelopathic properties. The minimum cidal concentration values of tea tree depended on duration of treatment. Cell viability was lost even at lower concentrations, if exposure to the essential oil was sufficiently long. Loss of vitality corresponded to rapid leakage of fluorescent dye 7-amino-4-chloromethylcoumarin from the vacuoles and cells. These cytological changes were monitored in real time and documented using time-lapse photography. The results have shown that tea tree oil has a major effect on membrane permeability not only in bacteria and fungi but also in plant cells. Melaleuca oils’ mode of action at the cellular level can explain the allelopathic properties (inhibition of germination and seedling growth) observed in nature. It suggested the potential use of tea tree oil for weed control.