Abstract
Lead (Pb) is the second most toxic metal on Earth and is toxic to humans and other living things. In plants, Pb commonly inhibits growth when it is at a concentration in the soil of 30 mg/kg or more but several Pb tolerant plants have been reported. However, few studies have focused on plant response to Pb exposure, particularly at concentrations higher than 30 mg/kg. The assessment and evaluation of metal dose-dependent plant responses will assist in future phytoremediation studies. Therefore, this work documents the Pb concentration-dependent antioxidative response in Tetraena qataranse. Young seedlings were irrigated with 0, 25, 50, and 100 mg/L Pb every 48 h for seven weeks under greenhouse conditions. A phytotoxicity test showed that at the lowest treatment concentration, Pb stimulates growth. However, at 100 mg/L (1600 mg/kg Pb in the growth medium at harvest), the metal disrupted healthy growth in T. qataranse, particularly root development. Metal accumulation in the root was higher (up to 2784 mg/kg) than that of the shoot (1141.6 mg/kg). Activity assays of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and glutathione reductase (GR) showed a progressive increase in enzymatic activities due to Pb treatment. Together, the results of this study suggest that T. qataranse is a Pb hyperaccumulator. Increased antioxidant enzyme activity was essential to maintaining cellular homeostasis and assisted in the arid plant’s tolerance to Pb stress.
Highlights
Lead (Pb) is the second most toxic metal on Earth and is toxic to humans and other living things
PCs are induced by phytochelatins synthase (PCS), an enzyme that is triggered when metal ions are p resent[26]
Plants tend to be more susceptible to metal toxicity after g ermination[11]
Summary
Lead (Pb) is the second most toxic metal on Earth and is toxic to humans and other living things. Few studies have focused on plant response to Pb exposure, at concentrations higher than 30 mg/kg. The assessment and evaluation of metal dose-dependent plant responses will assist in future phytoremediation studies. Toxic metals, including Pb, are some pollutants that are most dangerous to human health. It is generally toxic to most plants at a soil concentration higher than 30 mg/kg[4 ]. Though metal concentrations in the soil were relatively low, our study found Tetraena qataranse to be the most promising for phytoremediation. Studying promising plant’s responses to toxic metal exposure will help in overcoming such a limitation. In this regard, high metal accumulation in plant tissues provides the perfect condition for evaluating such responses. Toxic metals, including Pb, interferes with cellular homeostasis by generating reactive
Sign-in/Register to view highlights & summary 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.
