High-efficiency antioxidant system, chelating system and stress-responsive genes enhance tolerance to cesium ionotoxicity in Indian mustard (Brassica juncea L.)

• Published in: Ecotoxicology and environmental safety 2019-10, Vol.181, p.491-498
• Main Authors: Lai, Jin-long, Luo, Xue-gang
• Format: Article
• Language: English
• Subjects: Antioxidant system; Cesium; Gene expression; Indian mustard; Ionic toxicity; ROS
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2019.06.048

Indian mustard (Brassica juncea L.) was more tolerance to Cs than some sensitive plants, such as Arabidopsis thaliana and Vicia faba, and may have a special detoxification mechanism. In this study, the effects on reactive oxygen species (ROS) content, the antioxidant enzyme system and chelation system in Indian mustard were studied by observing different plant physiological responses. In addition, we focused on the analysis of gene regulatory networks related to ROS formation, ROS scavenging system, and other stress-response genes to Cs exposure using a transcriptome-sequencing database. The results showed that ROS and malonaldehyde content in seedlings increased significantly in Cs-treatment groups. The enzyme activities of superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase were increased, and the synthesis of antioxidants glutathione, phytochelatin and metallothionein also increased under Cs treatment. Further analysis showed that ROS formation pathways were primarily the photosynthetic electron transport chain process and photorespiration process in the peroxisome. Antioxidant enzyme systems and the respiratory burst oxidase homolog protein-mediated signal transduction pathway played a key role in ROS scavenging. In summary, one of the mechanisms of tolerance and detoxification of Indian mustard to Cs was that it enhanced the scavenging ability of antioxidant enzymes to ROS, chelated free Cs ions in cells and regulated the expression of related disease-resistant genes. •Cs induced the synthesis of sulfhydryl peptides, which might combine with Cs to form chelating peptide complexes.•The antioxidant enzyme system (SOD, POD, CAT, and APX) in Indian mustard was enhanced under Cs-induced conditions.•Indian mustard quickly turned on stress-related genes and alleviated the Cs toxicity.