Inoculation with abscisic acid (ABA)-catabolizing bacteria can improve phytoextraction of heavy metal in contaminated soil. (February 2020)

• Record Type: Journal Article
• Authors: Lu, Qi; Weng, Yineng; You, Yue; Xu, Qianru; Li, Haiyue; Li, Yuan; Liu, Huijun; Du, Shaoting
• Is Part Of: Environmental pollution. Volume 257(2020)
• Publication Date: 2020-02
• Subjects: ABA-catabolizing bacteria -- Heavy metal -- Phytoextraction -- Metal transporter; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2019.113497
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Promotion of plant capacity for accumulation of heavy metals (HMs) is one of the key strategies in enhancing phytoremediation in contaminated soils. Here we report that, Rhodococcus qingshengii, an abscisic acid (ABA)-catabolizing bacteria, clearly boosts levels of Cd, Zn, and Ni in wild-type Arabidopsis by 47, 24, and 30%, respectively, but no increase in Cu was noted, when compared with non-inoculated Arabidopsis plants in contaminated growth substrate. Furthermore, when compared with wild-type plants, R.qingshengii- induced increases in Cd, Zn, and Ni concentrations were more pronounced in abi1/hab1/abi2 (ABA-sensitive mutant) strains of Arabidopsis, whereas little effect was observed in snrk2.2/2.3 (ABA insensitive mutant). This demonstrates that metabolizing ABA might be indispensable for R. qingshengii to improve metal accumulation in plants. Bacterial inoculation significantly elevated the expression of Cd, Zn, and Ni-related transporters; whereas the transcript levels of Cu transporters remained unchanged. This result may be a reasonable explanation for why the uptake of Cd, Zn, and Ni in plants was stimulated by bacterial inoculation, while no effect was observed on Cu levels. From our results, we clearly demonstrate that R. qingshengii can increase the accumulation of Cd, Zn, and Ni in plants via an ABA-mediated HM transporters-associated mechanism. Metabolizing ABA in the plants by ABA-catabolizing bacterial inoculation might be an alternative strategy to improve phytoremediation efficiency in HMs contaminated soil. Graphical abstract: Image 1 Highlights: R. qingshengii improved the phytoextraction efficacy of Cd, Zn, and Ni, but not Cu. R. qingshengii improved plant uptake of Cd, Zn, and Ni by an ABA-mediated process. R. qingshengii upregulated expression of Cd, Zn, and Ni associated transporters. R. qingshengii did not significantly affect Cu transporter transcription levels. R.qingshengii barely affected Cd, Zn, and Ni uptake in the irt1 deletion mutants. Abstract : Inoculation with R. qingshengii could increase the accumulation of Cd, Zn, and Ni in plants via an ABA-mediated HM transporter-associated (mostly of IRT1) mechanism.