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Zhu QY, Ren ML, Jiang YJ, He C, Ding ZJ, Zheng SJ, Wang ZG, Jin CW. Co-mutation of OsLPR1/3/4/5 provides a promising strategy to minimize Cd contamination in rice grains. JOURNAL OF HAZARDOUS MATERIALS 2024; 476:135165. [PMID: 38996675 DOI: 10.1016/j.jhazmat.2024.135165] [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: 05/26/2024] [Revised: 06/25/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024]
Abstract
Minimizing cadmium (Cd) contamination in rice grains is crucial for ensuring food security and promoting sustainable agriculture. Utilizing genetic modification to generate rice varieties with low Cd accumulation is a promising strategy due to its cost-effectiveness and operational simplicity. Our study demonstrated that the CRISPR-Cas9-mediated quadruple mutation of the multicopper oxidase genes OsLPR1/3/4/5 in the japonica rice cultivar Tongjing 981 had little effect on yields. However, a notable increase was observed in the cell wall functional groups that bind with Cd. As a result, the quadruple mutation of OsLPR1/3/4/5 enhanced Cd sequestration within the cell wall while reducing Cd concentrations in both xylem and phloem sap, thereby inhibiting Cd transport from roots to shoots. Consequently, Cd concentrations in brown rice and husk in oslpr1/3/4/5 quadruple mutants (qm) decreased by 52% and 55%, respectively, compared to the wild-type. These findings illustrate that the quadruple mutation of OsLPR1/3/4/5 is an effective method for minimizing Cd contamination in rice grains without compromising yields. Therefore, the quadruple mutation of OsLPR1/3/4/5 via biotechnological pathways may represent a valuable strategy for the generation of new rice varieties with low Cd accumulation.
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Affiliation(s)
- Qing Yang Zhu
- State Key Laboratory of Plant Environmental Resilience, Zhejiang University, Hangzhou 310058, China
| | - Meng Lian Ren
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China
| | - Yi Jie Jiang
- State Key Laboratory of Plant Environmental Resilience, Zhejiang University, Hangzhou 310058, China
| | - Chao He
- Institute of Environment Pollution Control and Treatment, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, Zhejiang, China
| | - Zhong Jie Ding
- State Key Laboratory of Plant Environmental Resilience, Zhejiang University, Hangzhou 310058, China
| | - Shao Jian Zheng
- State Key Laboratory of Plant Environmental Resilience, Zhejiang University, Hangzhou 310058, China
| | - Ze Gang Wang
- College of Bioscience and Biotechnology, Yangzhou University, Yangzhou 225009, China.
| | - Chong Wei Jin
- State Key Laboratory of Plant Environmental Resilience, Zhejiang University, Hangzhou 310058, China.
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Wang Z, Wang Y, Lü J, Li T, Li S, Nie M, Shi G, Zhao X. Silicon and selenium alleviate cadmium toxicity in Artemisia selengensis Turcz by regulating the plant-rhizosphere. ENVIRONMENTAL RESEARCH 2024; 252:119064. [PMID: 38710427 DOI: 10.1016/j.envres.2024.119064] [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: 11/21/2023] [Revised: 04/21/2024] [Accepted: 04/30/2024] [Indexed: 05/08/2024]
Abstract
Soil cadmium (Cd) pollution has emerged as a pressing concern due to its deleterious impacts on both plant physiology and human well-being. Silicon (Si) is renowned for its ability to mitigate excessive Cd accumulation within plant cells and reduce the mobility of Cd in soil, whereas Selenium (Se) augments plant antioxidant capabilities and promotes rhizosphere microbial activity. However, research focusing on the simultaneous utilization of Si and Se to ameliorate plant Cd toxicity through multiple mechanisms within the plant-rhizosphere remains comparatively limited. This study combined hydroponic and pot experiments to investigate the effects of the combined application of Si and Se on Cd absorption and accumulation, as well as the growth and rhizosphere of A. selengensis Turcz under Cd stress. The results revealed that a strong synergistic effect was observed between both Si and Se. The combination of Si and Se significantly increased the activity and content of enzymes and non-enzyme antioxidants within A. selengensis Turcz, reduced Cd accumulation and inhibiting its translocation from roots to shoots. Moreover, Si and Se application improved the levels of reducing sugar, soluble protein, and vitamin C, while reducing nitrite content and Cd bioavailability. Furthermore, the experimental results showed that the combination of Si and Se not only increased the abundance of core rhizosphere microorganisms, but also stimulated the activity of soil enzymes, which effectively limited the migration of Cd in the soil. These findings provided valuable insights into the effective mitigation of soil Cd toxicity to plants and also the potential applications in improving plant quality and safety.
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Affiliation(s)
- Zhen Wang
- School of Environmental Science and Engineering / Hubei Key Laboratory of Mine Environmental Pollution Control & Remediation, Huei Polytechnic University, Huangshi 435003, China
| | - Yin Wang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Jiliang Lü
- School of Environmental Science and Engineering / Hubei Key Laboratory of Mine Environmental Pollution Control & Remediation, Huei Polytechnic University, Huangshi 435003, China.
| | - Tingqiang Li
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Shiqian Li
- Fujian Universities and Colleges Engineering Research Center of Modern Facility Agriculture, Fuqing 350300, China; Fujian Provincial Key Lab of Coastal Basin Environment (Fujian Polytechnic Normal Univeristy), Fuqing, 350300, China
| | - Min Nie
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Guangyu Shi
- College of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China
| | - Xiaohu Zhao
- Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental Resource Sciences, Zhejiang University, Hangzhou 310058, China; College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
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Wang S, He X, Tian J, Wu R, Liu H, Fang Z, Du S. NRT1.2 overexpression enhances the synergistic interplay between ABA-generating bacteria and biochars in reducing heavy metal accumulation in pak choi. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171276. [PMID: 38417500 DOI: 10.1016/j.scitotenv.2024.171276] [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: 01/01/2024] [Revised: 02/07/2024] [Accepted: 02/23/2024] [Indexed: 03/01/2024]
Abstract
The agricultural sector faces severe challenges owing to heavy metal (HM) contamination of farmlands, requiring urgent preventive measures. To address this, we investigated the impact of the synergistic application of Azospirillum brasilense, a growth-promoting rhizobacterium producing abscisic acid (ABA), and biochar to minimize HM accumulation in pak choi, using three distinct expression levels of the ABA transporter NRT1.2 in pak choi and three different types of contaminated soils as experimental materials. The results revealed that pak choi with low, medium, and high NRT1.2 expression intensity, when subjected to bacterial strain-biochar treatment, exhibited an increasing trend in ABA content compared to the control. Correspondingly, the aboveground HM content decreased by 1-49 %, 22-52 %, and 15-96 %, whereas the fresh weight increased by 12-38 %, 88-126 %, and 152-340 %, respectively, showing a significant correlation with NRT1.2 expression. Pearson correlation analysis demonstrated that NRT1.2 expression intensity was inversely associated with the combined treatment's reduction in HM accumulation and positively correlated with the promotional effect. Simultaneously, soil discrepancies significantly affected the combined treatment, which was likely associated with variations in the active forms of HM in each soil. Consequently, when employing ABA-producing bacteria for mitigating crop HM accumulation, selecting plants with higher relative NRT1.2 expression intensity, combined with biochar, is recommended.
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Affiliation(s)
- Shengtao Wang
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Xiaolin He
- Jiangxi Province Agricultural Technology Extension Center, Nanchang 330045, China
| | - Jiaying Tian
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Ran Wu
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Huijun Liu
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Zhiguo Fang
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Shaoting Du
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China.
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Zhu Y, Wang Y, Liu H, Wang H, Xie M, Fang Z, Du S. ABA-metabolizing bacteria and rhamnolipids as valuable allies for enhancing phytoremediation efficiency in heavy metal-contaminated soils. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 905:167398. [PMID: 37758153 DOI: 10.1016/j.scitotenv.2023.167398] [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: 09/05/2023] [Revised: 09/19/2023] [Accepted: 09/24/2023] [Indexed: 10/02/2023]
Abstract
Microbial-assisted phytoremediation has great potential to improve the efficiency of phytoremediation in heavy metal (HM)-contaminated soils. In this study, the synergistic effects of rhamnolipids and the abscisic acid (ABA)-metabolizing bacterium Rhodococcus qingshengii on the phytoremediation efficiency of Indian mustard (Brassica juncea) in HM-contaminated soils were investigated. The Cd, Zn, and Pb contents in plants treated with a combination of rhamnolipids and R. qingshengii were 48.4-77.1 %, 14.6-40.4 %, and 16.1-20.0 % higher, respectively, than in those treated with R. qingshengii alone, and 42.8-59.2 %, 13.1-48.2 %, and 7.3-67.5 % higher, respectively, than in those treated with rhamnolipids alone. In addition, the bioconcentration factors of each metal were improved, and the biomass further increased by 36.6-65.7 % compared to that of single treatments. Pearson's correlation analysis showed that rhamnolipids and R. qingshengii enhanced the accumulation of HMs in B. juncea by activating the available forms of HMs in the soil and regulating the ABA and indole-3-acetic acid in plants, respectively. The structural equation model indicated that R. qingshengii had a larger path coefficient than rhamnolipids in terms of HM content and plant biomass, suggesting that R. qingshengii may have a greater contribution to promoting the extraction of HMs from the soil under synergistic conditions. In conclusion, the combination of rhamnolipids and R. qingshengii has great potential to enhance the phytoremediation efficiency of hyperaccumulating plants in HM-contaminated soils.
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Affiliation(s)
- Yaxin Zhu
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China
| | - Yu Wang
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Huijun Liu
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Hua Wang
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, Zhejiang 321004, China
| | - Minghui Xie
- College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua, Zhejiang 321004, China
| | - Zhiguo Fang
- College of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, China
| | - Shaoting Du
- Key Laboratory of Pollution Exposure and Health Intervention of Zhejiang Province, Interdisciplinary Research Academy (IRA), Zhejiang Shuren University, Hangzhou 310015, China.
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