Abstract
One of the most significant biosphere contamination problems worldwide is derived from heavy metals. Heavy metals can be highly reactive and toxic according to their oxidation levels. Their toxic effects are associated with the increased production of reactive oxygen species (ROS) and cellular damage induced in plants. The present study focuses on the effects of nickel (Ni), copper (Cu), and zinc (Zn) applied to the soil on the antioxidant response and allergen production in the aromatic plant basil (Ocimum basilicum L.) following a combined physiological, biochemical and analytical approach. The concentrations used for the three heavy metals were based on the 2002 Regulation of the Polish Ministry of the Environment on Soil Quality Standards [(i) agricultural land (group B): Ni 100 ppm, Ni 210 ppm, Cu 200 ppm, Cu 500 ppm, Zn 720 ppm and (ii) industrial land (group C): Ni 500 ppm, Cu 1000 ppm, Zn 1500 ppm, Zn 3000 ppm]. The highest physiological and cellular damage in basil plants was caused by Cu and Zn. Increasing concentrations of Cu resulted in a further increase in cellular damage and nitro-oxidative stress, correlating with an induction in activity of reactive oxygen and nitrogen species metabolism enzymes (SOD, CAT, APX, NR). Treatment with Cu led to increased concentration of the allergenic protein profilin, while increasing concentrations of Cu and Zn led to a decrease in the concentration of total proteins (likely due to proteolysis) and antioxidant capacity. Interestingly, severe Cu stress resulted in the accumulation of specific proteins related to transpiration and photosynthetic processes. On the basis of these findings, Ni stress in basil plants appears to be less damaging and with lower allergenic potential compared with Cu and Zn stress, while Cu-stressed basil plants experience most detrimental effects and display highest allergen production.
Highlights
A large number of plant genera exists which belong to the Lamiaceae family and include common herb spices
Samples were analyzed using the ICP-MS method, which revealed that increasing concentrations of heavy metals (Ni 100–500 ppm, Cu 200–1000 ppm, and Zn 720 ppm) applied to treated plants correlates with increasing ion accumulation in plant leaves, validating the successful application of heavy metals as previously reported in Szczodrowska et al (2016)
After 17 days, no phenotypic differences were observed in basil seedlings between Cu (200, 500, 1000 ppm), Zn 720 ppm and control plants, except for Ni (100, 210, 500 ppm), which showed lower germination rate compared with control plants, and the higher concentrations of Zn (1500, 3000 ppm) which appeared to have chlorotic leaves (Supplementary Figure S2)
Summary
A large number of plant genera exists which belong to the Lamiaceae family and include common herb spices. One of them is the genus Ocimum which includes 50–150 species of herbs and shrubs (Javanmardi et al, 2003). Basil (Ocimum basilicum L.), a well-known herb, has been planted and used form ancient times and is abundant in tropical and subtropical regions (Khakdan et al, 2016). In the extracts of these plants, a number of phenolic compounds (such as flavonoids, phenolic acids, and phenolic diterpenes) with strong antioxidant activity have been found. These antioxidant qualities have the ability to maintain health and prevent from coronary heart disease and cancer (Javanmardi et al, 2003)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
