Excess Zinc Supply Reduces Cadmium Uptake and Mitigates Cadmium Toxicity Effects on Chloroplast Structure, Oxidative Stress, and Photosystem II Photochemical Efficiency in Salvia sclarea Plants

• Published in: Toxics (Basel) Vol. 10; no. 1; p. 36
• Main Authors: Sperdouli, Ilektra, Adamakis, Ioannis-Dimosthenis S, Dobrikova, Anelia, Apostolova, Emilia, Hanć, Anetta, Moustakas, Michael
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 12.01.2022; MDPI
• Subjects: Accumulation; Antiinfectives and antibacterials; Binding sites; Cadmium; Chlorophyll; chlorophyll fluorescence; Chloroplasts; clary sage; Food chains; Fungicides; Health risks; Herbal medicine; hydroponic culture; Leaves; Lipid peroxidation; Lipids; Mass spectrometry; Medicinal plants; Metabolism; Oxidative stress; Peroxidation; Photochemicals; Photochemistry; photosynthesis; Photosystem II; phytotoxicity; reactive oxygen species; Redox properties; Salvia sclarea; Scientific imaging; Side effects; Soil contamination; Toxicity; Translocation; Ultrastructure; Zinc; Zinc sulfate; Germany; non photochemical quenching; phytotoxicity; photosynthesis; chlorophyll fluorescence; hydrogen peroxide; reactive oxygen species; quinone A (QA); redox state; clary sage; hydroponic culture
• ISSN: 2305-6304; 2305-6304
• DOI: 10.3390/toxics10010036

L. is a Cd tolerant medicinal herb with antifungal and antimicrobial properties cultivated for its pharmacological properties. However, accumulation of high Cd content in its tissues increases the adverse health effects of Cd in humans. Therefore, there is a serious demand to lower human Cd intake. The purpose of our study was to evaluate the mitigative role of excess Zn supply to Cd uptake/translocation and toxicity in clary sage. Salvia plants were treated with excess Cd (100 μM CdSO ) alone, and in combination with Zn (900 μM ZnSO ), in modified Hoagland nutrient solution. The results demonstrate that plants exposed to Cd toxicity accumulated a significant amount of Cd in their tissues, with higher concentrations in roots than in leaves. Cadmium exposure enhanced total Zn uptake but also decreased its translocation to leaves. The accumulated Cd led to a substantial decrease in photosystem II (PSII) photochemistry and disrupted the chloroplast ultrastructure, which coincided with an increased lipid peroxidation. Zinc application decreased Cd uptake and translocation to leaves, while it mitigated oxidative stress, restoring chloroplast ultrastructure. Excess Zn ameliorated the adverse effects of Cd on PSII photochemistry, increasing the fraction of energy used for photochemistry (Φ ) and restoring PSII redox state and maximum PSII efficiency ( / ), while decreasing excess excitation energy at PSII (EXC). We conclude that excess Zn application eliminated the adverse effects of Cd toxicity, reducing Cd uptake and translocation and restoring chloroplast ultrastructure and PSII photochemical efficiency. Thus, excess Zn application can be used as an important method for low Cd -accumulating crops, limiting Cd entry into the food chain.