Mechanisms involved in the sequestration and resistance of cadmium for a plant-associated Pseudomonas strain

• Published in: Ecotoxicology and environmental safety Vol. 266; p. 115527
• Main Authors: Huang, Mingyu, Shen, Shili, Meng, Zhuang, Si, Guangzheng, Wu, Xinni, Feng, Tingting, Liu, Chang’e, Chen, Jinquan, Duan, Changqun
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.11.2023; Elsevier
• Subjects: Cd sequestration; Microremediation; Molecular Cd-resistance; Cd sequestration; Microremediation; Molecular Cd-resistance
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2023.115527

Understanding Cd-resistant bacterial cadmium (Cd) resistance systems is crucial for improving microremediation in Cd-contaminated environments. However, these mechanisms are not fully understood in plant-associated bacteria. In the present study, we investigated the mechanisms underlying Cd sequestration and resistance in the strain AN-B15. These results showed that extracellular Cd sequestration by complexation in strain AN-B15 was primarily responsible for the removal of Cd from the solution. Transcriptome analyses have shown that the mechanisms of Cd resistance at the transcriptional level involve collaborative processes involving multiple metabolic pathways. The AN-B15 strain upregulated the expression of genes related to exopolymeric substance synthesis, metal transport, Fe-S cluster biogenesis, iron recruitment, reactive oxygen species oxidative stress defense, and DNA and protein repair to resist Cd-induced stress. Furthermore, inoculation with AN-B15 alleviated Cd-induced toxicity and reduced Cd uptake in the shoots of wheat seedlings, indicating its potential for remediation. Overall, the results improve our understanding of the mechanisms involved in Cd resistance in bacteria and thus have important implications for improving microremediation. [Display omitted] •Strain AN-B15 effectively sequestered Cd mainly by complexation.•Formation of CdS nanoparticles partially explains Cd sequestration by AN-B15.•Cd resistance in strain AN-B15 is a collaborative process involving multiple metabolic systems at the transcriptional level.•AN-B15 strain reduced Cd accumulation and phytotoxicity in plants.