The oxidative stress in Ambrosia artemisiifolia L. shoots grown in vitro induced by Nepeta rtanjensis and N. cataria essential oils

Abstract

The possibility of using essential oil (EO) of Nepeta rtanjensis and N. cataria as bioherbicides against Ambrosia artemisiifolia L., an important weed and allergen species, was explored. In vitro culture experimental system of A. artemisiifolia has been established and ragweed shoots were exposed to the atmosphere enriched with volatile compounds (VOCs) emitted from EOs. N. rtanjensis EO was characterized by high amounts of 4aα,7α,7aβ-nepetalactone (trans,cis-nepetalactone), while N. cataria EO possessed high amounts of 4aα,7α,7aα-nepetalactone (cis,trans-nepetalactone). Reduction in A. artemisiifolia shoots growth and their discoloration, in the presence of N. rtanjensis and N. cataria EOs (2% and 4%, final nepetalactone concentrations) was observed after 2 weeks of exposure. An antioxidative defense system of A. artemisiifolia was activated by increasing peroxidases activity or by inactivating catalases and superoxide dismutases activity. Overall, stronger inhibitory effect on shoot growth, CAT activity, and stimulating POX activity was observed for N. cataria EO. N. rtanjensis EO was more efficient in inhibiting rooting and root growth, and in suppressing SOD activity. Therefore, EOs of N. rtanjensis and N. cataria might be recommended as potential bioherbicides against highly allergenic and weed species A. artemisiifolia. Further exploration of EOs’ mode of action, confirmation of phytotoxicity in field conditions, and feasibility assessment for the commercial production and application in agricultural practice, is the course of our further work.