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Wu C, Wu Y, Li F, Ding X, Yi S, Hang S, Ge F, Zhang M. Reducing the accumulation of cadmium and phenanthrene in rice by optimizing planting spacing: Role of low-abundance but core rhizobacterial communities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171856. [PMID: 38522531 DOI: 10.1016/j.scitotenv.2024.171856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 03/26/2024]
Abstract
Optimizing planting spacing is a common agricultural practice for enhancing rice growth. However, its effect on the accumulation of cadmium (Cd) and phenanthrene (Phen) in soil-rice systems and the response mechanisms of rhizobacteria to co-contaminants remain unclear. This study found that reducing rice planting spacing to 5 cm and 10 cm significantly decreased the bioavailability of Cd (by 7.9 %-29.5 %) and Phen (by 12.9 %-47.6 %) in the rhizosphere soil by converting them into insoluble forms. The increased accumulation of Cd and Phen in roots and iron plaques (IPs) ultimately led to decreased Cd (by 32.2 %-39.9 %) and Phen (by 4.2 %-17.3 %) levels in brown rice, and also significantly affected the composition of rhizobacteria. Specifically, reducing rice planting spacing increased the abundance of low-abundance but core rhizobacteria in the rhizosphere soil and IPs, including Bacillus, Clostridium, Sphingomonas, Paenibacillus, and Leifsonia. These low-abundance but core rhizobacteria exhibited enhanced metabolic capacities for Cd and Phen, accompanied by increased abundances of Cd-resistance genes (e.g., czcC and czcB) and Phen-degradation genes (e.g., pahE4 and pahE1) within the rhizosphere soil and IPs. Reduced planting spacing had no noticeable impact on rice biomass. These findings provide new insights into the role of low-abundance but core rhizobacterial communities in Cd and Phen uptake by rice, highlighting the potential of reduced planting spacing as an eco-friendly strategy for ensuring the safety of rice production on contaminated paddy soils.
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Affiliation(s)
- Chen Wu
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Yujun Wu
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Feng Li
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China.
| | - Xiangxi Ding
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Shengwei Yi
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Sicheng Hang
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Fei Ge
- College of Environment and Resources, Xiangtan University, Xiangtan, 411105, China; Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan 411105, China; Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan 411105, China; The Experimental Teaching Center in College of Environment and Resources, Xiangtan University, Xiangtan 411105, China
| | - Ming Zhang
- Department of Environmental Engineering, China Jiliang University, Hangzhou 310018, China
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Yi S, Zhu Z, Li F, Zhu L, Wu C, Ge F, Ji X, Tian J. Metagenomic and proteomic insights into the self-adaptive cell surface hydrophobicity of Sphingomonas sp. strain PAH02 reducing the migration of cadmium-phenanthrene co-pollutant in rice. Environ Microbiol 2024; 26:e16577. [PMID: 38183371 DOI: 10.1111/1462-2920.16577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/21/2023] [Indexed: 01/08/2024]
Abstract
Cell surface hydrophobicity (CSH) dominates the interactions between rhizobacteria and pollutants at the soil-water interface, which is critical for understanding the dissipation of pollutants in the rhizosphere microzone of rice. Herein, we explored the effects of self-adaptive CSH of Sphingomonas sp. strain PAH02 on the translocation and biotransformation behaviour of cadmium-phenanthrene (Cd-Phe) co-pollutant in rice and rhizosphere microbiome. We evidenced that strain PAH02 reduced the adsorption of Cd-Phe co-pollutant on the rice root surface while enhancing the degradation of Phe and adsorption of Cd via its self-adaptive CSH in the hydroponic experiment. The significant upregulation of key protein expression levels such as MerR, ARHDs and enoyl-CoA hydratase/isomerase, ensures self-adaptive CSH to cope with the stress of Cd-Phe co-pollutant. Consistently, the bioaugmentation of strain PAH02 promoted the formation of core microbiota in the rhizosphere soil of rice (Oryza sativa L.), such as Bradyrhizobium and Streptomyces and induced gene enrichment of CusA and PobA that are strongly associated with pollutant transformation. Consequently, the contents of Cd and Phe in rice grains at maturity decreased by 17.2% ± 0.2% and 65.7% ± 0.3%, respectively, after the bioaugmentation of strain PAH02. These findings present new opportunities for the implementation of rhizosphere bioremediation strategies of co-contaminants in paddy fields.
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Affiliation(s)
- Shengwei Yi
- College of Environment and Resources, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan University, Xiangtan, China
| | - Zhongnan Zhu
- College of Environment and Resources, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan University, Xiangtan, China
| | - Feng Li
- College of Environment and Resources, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan University, Xiangtan, China
| | - Lizhong Zhu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Chen Wu
- College of Environment and Resources, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan University, Xiangtan, China
| | - Fei Ge
- College of Environment and Resources, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan University, Xiangtan, China
| | - Xionghui Ji
- Hunan Institute of Agro-Environment and Ecology, Hunan Academy of Agricultural Sciences, Changsha, China
| | - Jiang Tian
- College of Environment and Resources, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental and Ecological Health, Xiangtan University, Xiangtan, China
- Hunan Provincial University Key Laboratory for Environmental Behavior and Control Principle of New Pollutants, Xiangtan University, Xiangtan, China
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Zhou M, Wang J, Zhou J, Liu L, Yang R, Xu J, Liang M, Xu L. Exogenous IAA application affects the specific characteristics of fluoranthene distribution in Arabidopsis. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115306. [PMID: 37515970 DOI: 10.1016/j.ecoenv.2023.115306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/19/2023] [Accepted: 07/24/2023] [Indexed: 07/31/2023]
Abstract
Indole-3-acetic acid (IAA) is a crucial growth regulator involved in the accumulation of polycyclic aromatic hydrocarbons (PAHs). However, the precise physiological and molecular mechanisms underlying IAA-mediated plant growth and PAH accumulation are not yet fully understood. In this study, two distinct IAA-sensitive genotypes of Arabidopsis thaliana (wild type and Axr5 mutant) were chosen to investigate the mechanisms of fluoranthene (Flu) uptake and accumulation in plant tissues (roots and leaves) through physiological and molecular analyses. The results revealed that the Flu concentration in Axr5 leaves was significantly higher than that in wild-type (WT) leaves. In roots, the Flu content decreased significantly with increasing IAA treatment, while no significant changes were observed with lower IAA treatment. Principal component analysis demonstrated that Flu accumulation in Arabidopsis roots was associated with IAA concentrations, whereas Flu accumulation in leaves was dependent on the genotype. Moreover, Flu accumulation showed a positive correlation with the activity of glutathione S-transferase (GST) and root length and a positive correlation with catalase (CAT) and peroxidase (POD) activity in the leaves. Transcriptome analysis confirmed that the expression of the ethylene-related gene ATERF6 and GST-related genes ATGSTF14 and ATGSTU27 in roots, as well as the POD-related genes AtPRX9 and AtPRX25 and CAT-related gene AtCAT3 in leaves, played a role in Flu accumulation. Furthermore, WRKY transcription factors (TFs) in roots and NAC TFs in leaves were identified as important regulators of Flu accumulation. Understanding the mechanisms of Flu uptake and accumulation in A. thaliana provides valuable insights for regulating PAH accumulation in plants.
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Affiliation(s)
- Mengjia Zhou
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210014, China
| | - Ji Wang
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jing Zhou
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210014, China
| | - Lin Liu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ruixuan Yang
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jingjing Xu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Mingxiang Liang
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Li Xu
- Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing 210014, China.
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