Abstract
Plants suffer from combined stress of sulfur deficiency and cadmium toxicity in some agricultural lands. However, little is known about the reaction in plants, such as responses in antioxidant enzymes and non-protein thiol compounds, to such combined stress. Therefore, in this study, four treatments, S-sufficiency (TS-Cd), S-deficiency (T-S-Cd), Cd stress (TS+Cd) and combined stress of S-deficiency and Cd stress (T-S+Cd), were set up to investigate (1) the effects of sulfur deficiency or sulfur sufficiency on Cd toxicity to kidney bean cultivar seedlings and the related mechanisms, and (2) the responses of two kidney bean cultivars to combined stress of S-deficiency and Cd-tolerance. The results showed significant increases in hydrogen peroxide (H2O2) and malondialdehyde contents and significant increases in antioxidant enzyme (superoxide dismutase, catalase, peroxidase, and glutathione S-transferase) activities and non-protein thiol compounds (non-protein thiols, reduced glutathione, phytochelatins) synthesis in the plants in TS+Cd and T-S+Cd. On the tissue level, higher proportion of Cd was found to be immobilized/deposited in roots, while on the sub-cell level, higher proportion of Cd was located in cell walls and vacuole fractions with lower in cell organelles. Taken together, the results indicated that Cd detoxification was achieved by the two kidney bean cultivars through antioxidant enzyme activation, non-protein thiol compound synthesis and sub-cellular compartmentalization. In addition, the results indicated that sufficient S supply helped to relieve Cd toxicity, which is of special significance for remediation or utilization of Cd-contaminated soils as S is a plant essential nutrient.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: 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.