Research articleGlutathione-induced alleviation of cadmium toxicity in Zea mays

- External GSH alleviated Cd-toxicity, reduced Cd translocation and ROS in maize plants.
- GSH suppressed Cd-induced increase in ABA content and ethylene emission rate.
- GSH elevated the expression level of Cd-tolerance related genes.
- GSH affected stoma development, reduced the percentages of closed stomata, and improved photosynthesis performance of Cd-stressed plants.
- GSH counteracted Cd-induced alterations of GSH/GSSG ratio, leaf and root ultrastructure, and ×¥-GCS, SOD and POD activity.

Glutathione (GSH) is known to alleviate cadmium (Cd) stress in many plant species. However, the comprehensive mechanisms responsible for this effect in maize are still need more investigation. Here, a combination of physiological and molecular approaches was utilized in GSH-Cd treated maize seedlings, which revealed that GSH reversed the adverse effects of Cd, as reflected by plant growth, plant hormones, vacuole, stoma development, gene expression, etc. Plant growth, root cell viability, photosynthetic capacity, redox equilibrium, and cell ultrastructure recovery following GSH treatment, coupled with the strong up-regulation of Cd tolerance-related genes (e.g., phytochelatin synthetase-like protein, MYB and WRKY transcription factors, and CYP450), demonstrated the efficient activation of cellular defense against Cd toxicity. The addition of GSH significantly elevated GSH/GSSG ratio and the activity of γ-glutamylcysteine synthetase in both shoots and roots and markedly reduced Cd concentration in shoots. Ethylene emission rate and abscisic acid (ABA) content were significantly reduced after GSH application in the presence of Cd, except ABA content in leaves. These findings highlighted the significance of GSH in alleviating Cd-stress in maize and indicate a promising strategy for safe food production.

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