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Emamverdian A, Khalofah A, Pehlivan N, Li Y, Chen M, Liu G. Iron nanoparticles in combination with other conventional Fe sources remediate mercury toxicity-affected plants and soils by nutrient accumulation in bamboo species. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 278:116431. [PMID: 38718730 DOI: 10.1016/j.ecoenv.2024.116431] [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: 11/14/2023] [Revised: 04/30/2024] [Accepted: 05/03/2024] [Indexed: 05/26/2024]
Abstract
The issue of mercury (Hg) toxicity has recently been identified as a significant environmental concern, with the potential to impede plant growth in forested and agricultural areas. Conversely, recent reports have indicated that Fe, may play a role in alleviating HM toxicity in plants. Therefore, this study's objective is to examine the potential of iron nanoparticles (Fe NPs) and various sources of Fe, particularly iron sulfate (Fe SO4 or Fe S) and iron-ethylene diamine tetra acetic acid (Fe - EDTA or Fe C), either individually or in combination, to mitigate the toxic effects of Hg on Pleioblastus pygmaeus. Involved mechanisms in the reduction of Hg toxicity in one-year bamboo species by Fe NPs, and by various Fe sources were introduced by a controlled greenhouse experiment. While 80 mg/L Hg significantly reduced plant growth and biomass (shoot dry weight (36%), root dry weight (31%), and shoot length (31%) and plant tolerance (34%) in comparison with control treatments, 60 mg/L Fe NPs and conventional sources of Fe increased proline accumulation (32%), antioxidant metabolism (21%), polyamines (114%), photosynthetic pigments (59%), as well as root dry weight (25%), and shoot dry weight (22%), and shoot length (22%). Fe NPs, Fe S, and Fe C in plant systems substantially enhanced tolerance to Hg toxicity (23%). This improvement was attributed to increased leaf-relative water content (39%), enhanced nutrient availability (50%), improved antioxidant capacity (34%), and reduced Hg translocation (6%) and accumulation (31%) in plant organs. Applying Fe NPs alone or in conjunction with a mixture of Fe C and Fe S can most efficiently improve bamboo plants' tolerance to Hg toxicity. The highest efficiency in increasing biochemical and physiological indexes under Hg, was related to the treatments of Fe NPs as well as Fe NPs + FeS + FeC. Thus, Fe NPs and other Fe sources might be effective options to remove toxicity from plants and soil. The future perspective may help establish mechanisms to regulate environmental toxicity and human health progressions.
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Affiliation(s)
- Abolghassem Emamverdian
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; Bamboo Research Institute, Nanjing Forestry University, Nanjing 210037, China
| | - Ahlam Khalofah
- Biology Department, Faculty of Science, King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia; Research Center for Advanced Materials Science (RCAMS), King Khalid University, P.O. Box 9004, Abha 61413, Saudi Arabia
| | - Necla Pehlivan
- Department of Biology, Recep Tayyip Erdogan University, Rize 53100, Turkiye
| | - Yang Li
- Department of Mathematical Sciences, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Moxian Chen
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China.
| | - Guohua Liu
- Co-Innovation Center for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing 210037, China; Bamboo Research Institute, Nanjing Forestry University, Nanjing 210037, China.
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Ren J, Lu H, Lu S, Huang Z. Impacts of sulfamethoxazole stress on vegetable growth and rhizosphere bacteria and the corresponding mitigation mechanism. Front Bioeng Biotechnol 2024; 12:1303670. [PMID: 38390364 PMCID: PMC10882545 DOI: 10.3389/fbioe.2024.1303670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 01/02/2024] [Indexed: 02/24/2024] Open
Abstract
Antibiotics are an important pharmaceutical class excessively used by humans. Its presence in the soil can impact plant growth and induce antibiotic resistance. This research studies the effect of sulfamethoxazole (SMX) on plant growth, rhizosphere bacteria composition, and resistance genes. Two sets of vegetables (basil, cilantro, and spinach) were treated separately with water and SMX solution. The plant growth data and soil samples were collected and analyzed. The results revealed that SMX increased spinach leaf length (34.0%) while having no significant impacts on basil and cilantro. On the other hand, SMX improved the bacterial diversity in all samples. The shifts in the abundance of plant growth-promoting bacteria could indirectly affect vegetable stem and leaf length. SMX also significantly increased the abundance of resistance genes Sul1 and Sul2. A further study into the correlation between bacteria highlights the importance of Shingomonas and Alfipia for inhibiting the spread of key resistance gene hosts, namely, Pseudomonas, Stenotrophomonas, and Agrobacterium. This research provides insight into SMX's impact on vegetable growth and microbial diversity. It also points out important microbial interactions that could potentially be utilized to mitigate ARG proliferation.
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Affiliation(s)
- Jiawei Ren
- State Key Laboratory of Environmental Criteria and Risk Assessment, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, China
- Lake Forest Academy, Lake Forest, IL, United States
| | - Hongbin Lu
- State Key Laboratory of Environmental Criteria and Risk Assessment, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, China
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, China
| | - Shaoyong Lu
- State Key Laboratory of Environmental Criteria and Risk Assessment, National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Zhanggen Huang
- State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, China
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Alp-Turgut FN, Ozfidan-Konakci C, Arikan B, Comak G, Yildiztugay E. Graphene oxide-based aerogel stimulates growth, mercury accumulation, photosynthesis-related gene expression, antioxidant efficiency and redox status in wheat under mercury exposure. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 342:123117. [PMID: 38086507 DOI: 10.1016/j.envpol.2023.123117] [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: 09/19/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/17/2023]
Abstract
Mercury (Hg) pollution is a global concern in cropland systems. Hg contamination causes a disruption in the growth, energy metabolism, redox balance, and photosynthetic activity of plants. In the removal of Hg toxicity, a recent critical strategy is the use of aerogels with biodegradability and biocompatibility. However, it is unknown how graphene oxide-based aerogels stimulate the defense systems in wheat plants exposed to Hg toxicity. Therefore, in this study, the photosynthetic, genetic, and biochemical effects of reduced graphene oxide aerogel treatments (gA; 50-100-250 mg L-1) were examined in wheat (Triticum aestivum) under Hg stress (50 μM HgCl2). The relative growth rate (RGR) significantly decreased (84%) in response to Hg stress. However, the reduced RGR and water relations (RWC) of wheat were improved by gA treatments. The impaired gas exchange levels (stomatal conductance, carbon assimilation rate, intercellular CO2 concentrations, and transpiration rate) caused by stress were reversed under Hg plus gAs. Additionally, stress hampered chlorophyll fluorescence (Fv/Fo, Fv/Fm), and under Hg toxicity the expression of psaA genes was reduced (>0.4-fold), but psaB gene was significantly up-regulated (>3-fold) which are the genes involved in PSI. By increasing expression patterns of both genes relating to PSI, gAs reversed the adverse consequences on Fv/Fo and Fv/Fm in the presence of excessive Hg concentration. The activities of glutathione S-transferase (GST), glutathione reductase (GR), catalase (CAT), ascorbate peroxidase (APX) and dehydroascorbate reductase (DHAR) decreased under Hg toxicity. On the other hand, the activities of superoxide dismutase (SOD), APX, GST, and glutathione peroxidase (GPX) increased following gA treatments against stress, leading to the successful elimination of toxic levels of H2O2 and lipid peroxidation (TBARS content) by decreasing the levels by about 30%, and 40%, respectively. By modulating enzyme/non-enzyme activity/contents including the AsA-GSH cycle, gAs contributed to the protection of the cellular redox state. Most important of all, gA applications were able to reduce Hg intake by approximately 66%. Therefore, these results showed that gAs were effective in highly inhibiting Hg uptake and could significantly increase wheat tolerance to toxicity by eliminating Hg-induced oxidative damage and inhibiting metabolic processes involved in photosynthesis. The findings obtained from the study provide a new perspective on the alleviation roles of reduced graphene oxide aerogels as an effective adsorbent for decreasing damages of mercury toxicity in wheat plants.
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Affiliation(s)
- Fatma Nur Alp-Turgut
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Ceyda Ozfidan-Konakci
- Department of Molecular Biology and Genetics, Faculty of Science, Necmettin Erbakan University, Meram, 42090, Konya, Turkey.
| | - Busra Arikan
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
| | - Gurbuz Comak
- Department of Chemical Engineering, Faculty of Engineering, Mersin University, Mersin, 33100, Turkey.
| | - Evren Yildiztugay
- Department of Biotechnology, Faculty of Science, Selcuk University, Selcuklu, 42130, Konya, Turkey.
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Jalil S, Nazir MM, Ali Q, Zulfiqar F, Moosa A, Altaf MA, Zaid A, Nafees M, Yong JWH, Jin X. Zinc and nano zinc mediated alleviation of heavy metals and metalloids in plants: an overview. FUNCTIONAL PLANT BIOLOGY : FPB 2023; 50:870-888. [PMID: 37598713 DOI: 10.1071/fp23021] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 07/30/2023] [Indexed: 08/22/2023]
Abstract
Heavy metals and metalloids (HMs) contamination in the environment has heightened recently due to increasing global concern for food safety and human livability. Zinc (Zn2+ ) is an important nutrient required for the normal development of plants. It is an essential cofactor for the vital enzymes involved in various biological mechanisms of plants. Interestingly, Zn2+ has an additional role in the detoxification of HMs in plants due to its unique biochemical-mediating role in several soil and plant processes. During any exposure to high levels of HMs, the application of Zn2+ would confer greater plant resilience by decreasing oxidative stress, maintaining uptake of nutrients, photosynthesis productivity and optimising osmolytes concentration. Zn2+ also has an important role in ameliorating HMs toxicity by regulating metal uptake through the expression of certain metal transporter genes, targeted chelation and translocation from roots to shoots. This review examined the vital roles of Zn2+ and nano Zn in plants and described their involvement in alleviating HMs toxicity in plants. Moving forward, a broad understanding of uptake, transport, signalling and tolerance mechanisms of Zn2+ /zinc and its nanoparticles in alleviating HMs toxicity of plants will be the first step towards a wider incorporation of Zn2+ into agricultural practices.
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Affiliation(s)
- Sanaullah Jalil
- The Key Laboratory for Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | | | - Qurban Ali
- Department of Plant Breeding and Genetics, Faculty of Agricultural Sciences, Punjab University, Lahore 54590, Pakistan
| | - Faisal Zulfiqar
- Department of Horticultural Sciences, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - Anam Moosa
- Department of Plant Pathology, Faculty of Agricultural and Environment, The Islamia University of Bahawalpur, Bahawalpur, Pakistan
| | | | - Abbu Zaid
- Department of Botany, Government Gandhi Memorial Science College, Jammu, India
| | - Muhammad Nafees
- Department of Horticultural Sciences, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur 63100, Pakistan
| | - Jean Wan Hong Yong
- Department of Biosystems and Technology, Swedish University of Agricultural Sciences, Alnarp 23456, Sweden
| | - Xiaoli Jin
- The Key Laboratory for Crop Germplasm Resource of Zhejiang Province, Zhejiang University, Hangzhou, Zhejiang 310058, China
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Salgado L, López-Sánchez CA, Colina A, Baragaño D, Forján R, Gallego JR. Hg and As pollution in the soil-plant system evaluated by combining multispectral UAV-RS, geochemical survey and machine learning. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:122066. [PMID: 37343919 DOI: 10.1016/j.envpol.2023.122066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/14/2023] [Accepted: 06/15/2023] [Indexed: 06/23/2023]
Abstract
The combination of a low-density geochemical survey, multispectral data obtained with Unmanned Aerial Vehicle-Remote Sensing (UAV-RS), and a machine learning technique was tested in the search for a statistically robust prediction of contaminant distribution in soil and vegetation, for zones with a highly variable pollutant load. To this end, a novel methodology was devised by means of a limited geochemical study of topsoil and vegetation combined with multispectral data obtained by UAV-RS. The methodology was verified in an area affected by Hg and As contamination that typifies abandoned mining-metallurgy sites in recent decades. A broad selection of spectral indices were calculated to evaluate soil-plant system response, and four machine learning techniques (Multiple Linear Regression, Random Forest, Generalized Boosted Models, and Multivariate Adaptive Regression Spline) were tested to obtain robust statistical models. Random Forest (RF) provided the best non-biased models for As and Hg concentration in soil and vegetation, with R2 and rRMSE (%) ranging from 0.501 to 0.630 and from 180.72 to 46.31, respectively, and with acceptable values for RPD and RPIQ statistics. The prediction and mapping of contaminant content and distribution in the study area were well enough adjusted to the geochemical data and revealed superior accuracy for As than Hg, and for vegetation than topsoil. The results were more precise than those obtained in comparable studies that applied satellite or spectrometry data. In conclusion, the methodology presented emerges as a powerful tool for studies addressing soil and vegetation pollution and an alternative approach to classical geochemical studies, which are time-consuming and expensive.
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Affiliation(s)
- L Salgado
- SMartForest Research Group, Department of Biology of Organisms and Systems Biology, University of Oviedo, 33600 Mieres, Spain; Environmental Biogeochemistry & Raw Materials Group and Institute of Natural Resources and Territorial Planning (INDUROT), University of Oviedo, 33600 Mieres, Spain
| | - C A López-Sánchez
- SMartForest Research Group, Department of Biology of Organisms and Systems Biology, University of Oviedo, 33600 Mieres, Spain
| | - A Colina
- Environmental Biogeochemistry & Raw Materials Group and Institute of Natural Resources and Territorial Planning (INDUROT), University of Oviedo, 33600 Mieres, Spain; Department of Geography, Campus del Milán, University of Oviedo, 33011 Oviedo, Spain
| | - D Baragaño
- Environmental Biogeochemistry & Raw Materials Group and Institute of Natural Resources and Territorial Planning (INDUROT), University of Oviedo, 33600 Mieres, Spain; Escuela Politécnica de Ingeniería de Minas y Energía, University of Cantabria, 39316 Torrelavega, Spain
| | - R Forján
- Environmental Biogeochemistry & Raw Materials Group and Institute of Natural Resources and Territorial Planning (INDUROT), University of Oviedo, 33600 Mieres, Spain; Plant Production Area, Department of Biology of Organisms and Systems Biology, University of Oviedo, 33600 Mieres, Spain
| | - J R Gallego
- Environmental Biogeochemistry & Raw Materials Group and Institute of Natural Resources and Territorial Planning (INDUROT), University of Oviedo, 33600 Mieres, Spain.
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Kováčik J, Husáková L, Piroutková M, Babula P. Mercury Content and Amelioration of Its Toxicity by Nitric Oxide in Lichens. PLANTS (BASEL, SWITZERLAND) 2023; 12:727. [PMID: 36840082 PMCID: PMC9967695 DOI: 10.3390/plants12040727] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/25/2023] [Accepted: 02/04/2023] [Indexed: 06/18/2023]
Abstract
Mercury (Hg) content measured in five epiphytic lichen species collected in Slovakia mountain forests ranged from 30 to 100 ng/g DW and was species-specific, decreasing in the order Hypogymnia > Pseudevernia > Usnea > Xanthoria > Evernia prunastri (but polluted sites had no impact on Hg amount in Xanthoria). Evernia was therefore used to study the impact of short-term exogenous Hg (100 µM, 24 h) and possible amelioration of Hg toxicity by nitric oxide (NO) donor sodium nitroprusside (SNP). NO was efficiently released from SNP as detected by two staining reagents and fluorescence microscopy and reduced Hg-induced ROS signal and absorption of Hg by thalli of Evernia prunastri. At the same time, NO ameliorated Hg-induced depletion of metabolites such as ascorbic acid and non-protein thiols, but not of free amino acids. The amount of metabolites, including soluble phenols, was reduced by excess Hg per se. On the contrary, NO was unable to restore Hg-stimulated depletion of chlorophyll autofluorescence but mitigated the decline of some macronutrients (K and Ca). Data confirm that accumulation of Hg in the epiphytic lichens is species-specific and that NO is a vital molecule in Evernia prunastri that provides protection against Hg-induced toxicity with considerable positive impact on metabolic changes.
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Affiliation(s)
- Jozef Kováčik
- Department of Biology, University of Trnava, Priemyselná 4, 918 43 Trnava, Slovak Republic
| | - Lenka Husáková
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573 HB/D, 532 10 Pardubice, Czech Republic
| | - Martina Piroutková
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573 HB/D, 532 10 Pardubice, Czech Republic
| | - Petr Babula
- Department of Physiology, Faculty of Medicine, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
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Rahman SU, Nawaz MF, Gul S, Yasin G, Hussain B, Li Y, Cheng H. State-of-the-art OMICS strategies against toxic effects of heavy metals in plants: A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 242:113952. [PMID: 35999767 DOI: 10.1016/j.ecoenv.2022.113952] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 06/15/2023]
Abstract
Environmental pollution of heavy metals (HMs), mainly due to anthropogenic activities, has received growing attention in recent decades. HMs, especially the non-essential carcinogenic ones, including chromium (Cr), cadmium (Cd), mercury (Hg), aluminum (Al), lead (Pb), and arsenic (As), have appeared as the most significant air, water, and soil pollutants, which adversely affect the quantity, quality, and security of plant-based food all over the world. Plants exposed to HMs could experience significant decline in growth and yield. To avoid or tolerate the toxic effects of HMs, plants have developed complicated defense mechanisms, including absorption and accumulation of HMs in cell organelles, immobilization by forming complexes with organic chelates, extraction by using numerous transporters, ion channels, signalling cascades, and transcription elements, among others. OMICS strategies have developed significantly to understand the mechanisms of plant transcriptomics, genomics, proteomics, metabolomics, and ionomics to counter HM-mediated stress stimuli. These strategies have been considered to be reliable and feasible for investigating the roles of genomics (genomes), transcriptomic (coding), mRNA transcripts (non-coding), metabolomics (metabolites), and ionomics (metal ions) to enhance stress resistance or tolerance in plants. The recent developments in the mechanistic understandings of the HMs-plant interaction in terms of their absorption, translocation, and toxicity invasions at the molecular and cellular levels, as well as plants' response and adaptation strategies against these stressors, are summarized in the present review. Transcriptomics, genomics, metabolomics, proteomics, and ionomics for plants against HMs toxicities are reviewed, while challenges and future recommendations are also discussed.
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Affiliation(s)
- Shafeeq Ur Rahman
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, Guangdong 523808, China; MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
| | - Muhammad Farrakh Nawaz
- Department of Forestry and Range Management, University of Agricultureó, Faisalabad, Pakistan
| | - Sadaf Gul
- Department of Botany, University of Karachi, Karachi, Pakistan
| | - Ghulam Yasin
- Department of Forestry and Range Management, Bahauddin Zakariya University Multan, Pakistan
| | - Babar Hussain
- Department of Plant Science Karakoram International University (KIU), Gilgit 15100, Gilgit-Baltistan, Pakistan
| | - Yanliang Li
- School of Environment and Civil Engineering, Dongguan University of Technology, Dongguan, Guangdong 523808, China; Dongguan Key Laboratory of Water Pollution and Ecological Safety Regulation, Dongguan, Guangdong 523808, China.
| | - Hefa Cheng
- MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
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Shao R, Zhang J, Shi W, Wang Y, Tang Y, Liu Z, Sun W, Wang H, Guo J, Meng Y, Kang G, Jagadish KS, Yang Q. Mercury stress tolerance in wheat and maize is achieved by lignin accumulation controlled by nitric oxide. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 307:119488. [PMID: 35597486 DOI: 10.1016/j.envpol.2022.119488] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 04/26/2022] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
Nitric oxide (NO) is an important phytohormone for plant adaptation to mercury (Hg) stress. The effect of Hg on lignin synthesis, NO production in leaf, sheath and root and their relationship were investigated in two members of the grass family - wheat and maize. Hg stress decreased growth and lignin contents, significantly affected phenylpropanoid and monolignol pathways (PAL, phenylalanine ammonia-lyase; 4-coumarate: CoA ligase, 4CL; cinnamyl alcohol dehydrogenase, CAD), with maize identified to be more sensitive to Hg stress than wheat. Among the tissue types, sheath encountered severe damage compared to leaves and roots. Hg translocation in maize was about twice that in wheat. Interestingly, total NO produced under Hg stress was significantly decreased compared to control, with maximum reduction of 43.4% and 42.9% in wheat and maize sheath, respectively. Regression analysis between lignin and NO contents or the activities of three enzymes including CAD, 4CL and PAL displayed the importance of NO contents, CAD, 4CL and PAL for lignin synthesis. Further, the gene expression profiles encoding CAD, 4CL and PAL provided support for the damaging effect of Hg on wheat sheath, and maize shoot. To validate NO potential to mitigate Hg toxicity in maize and wheat, NO donor and NO synthase inhibitor were supplemented along with Hg. The resulting phenotype, histochemical analysis and lignin contents showed that NO mitigated Hg toxicity by improving growth and lignin synthesis and accumulation. In summary, Hg sensitivity was higher in maize seedlings compared to wheat, which was associated with the lower lignin contents and reduced NO contents. External supplementation of NO is proposed as a sustainable approach to mitigate Hg toxicity in maize and wheat.
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Affiliation(s)
- Ruixin Shao
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Junjie Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Weiyu Shi
- Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station, School of Geographical Sciences, Southwest University, Chongqing, 400715, China.
| | - Yongchao Wang
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Yulou Tang
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Zikai Liu
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Wei Sun
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Hao Wang
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Jiameng Guo
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Yanjun Meng
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Guozhang Kang
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
| | - Krishna Sv Jagadish
- Department of Plant and Soil Science, Texas Tech University, Lubbock, TX, 79410, USA.
| | - Qinghua Yang
- National Key Laboratory of Wheat and Maize Crop Science, Key Laboratory of Regulating and Controlling Crop Growth and Development Ministry of Education, Henan Agricultural University, Zhengzhou, Henan, 450046, China.
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Kalinhoff C, Calderón NT. Mercury Phytotoxicity and Tolerance in Three Wild Plants during Germination and Seedling Development. PLANTS 2022; 11:plants11152046. [PMID: 35956524 PMCID: PMC9370237 DOI: 10.3390/plants11152046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/16/2022]
Abstract
By examining plant responses to heavy metal stress during the early stages of the life cycle, we can predict their tolerance and survival in polluted areas as well as their potential for bioremediation. The objective of our study was to evaluate the effect of exposure to mercury (Hg) on the germination and in vitro development of three plant species: Bidens pilosa, Taraxacum officinale (Asteraceae), and Heliocarpus americanus (Malvaceae). These are wild ecotypes adapted to local edaphoclimatic conditions in southern Ecuador, an area which has been historically affected by artisanal and small-scale gold mining (SSGM). For comparison, we additionally used a known Hg-tolerant plant, Lactuca sativa (Asteraceae). We tested biorelevant concentrations of Hg, equivalent to those occurring in soils affected by SSGM, i.e., up to 4.0 mg/L of Hg. The relative inhibitory effects of the treatments (0.6, 2.0, and 4.0 mg/L of Hg) on the germination percentage were most evident in T. officinale, followed by B. pilosa, while L. sativa and H. americanus were not affected. In terms of the time needed to reach 50% germination (T50), B. pilosa exposed to higher concentrations of Hg showed an increase in T50, while H. americanus showed a significant reduction compared to the control treatment. The reduction in radicle length at 4.0 mg/L Hg compared to the control was more evident in L. sativa (86%) than in B. pilosa (55.3%) and H. americanus (31.5%). We concluded that, in a scenario of Hg contamination in the evaluated concentration range, the grass B. pilosa and the tree H. americanus could have a higher probability of establishment and survival.
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Syntrichia caninervis adapt to mercury stress by altering submicrostructure and physiological properties in the Gurbantünggüt Desert. Sci Rep 2022; 12:11717. [PMID: 35810254 PMCID: PMC9271083 DOI: 10.1038/s41598-022-15822-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 06/29/2022] [Indexed: 11/30/2022] Open
Abstract
Sewage and industrial waste discharges have been found to have a deleterious effect on plant growth and environmental safety through the accumulation of trace metal mercury (Hg) in soils. Although the effects of Hg on vascular plants have been reported in terms of enzyme activity, oxidative damage and physiology, few studies have been done on non-vascular plants. A simulation experiment including 7 Hg concentrations (0, 10, 20, 30, 40, 50, 75 µM) was conducted to investigate the influence of Hg stress on ultrastructure and physiological properties of biocrust moss Syntrichia. caninervis across 7 consecutive days. The results showed that the lowest lethal concentration of S. caninervis was 30 µM Hg. The mortality rate of the plants increased significantly with Hg concentrations. The ultrastructure did not change significantly at Hg concentration ≤ 20 µM, while exceeding which, cell walls began to separate, nuclei began to blur, and chloroplasts began to expand. The soluble sugars (SS), peroxidase (POD), and superoxide dismutase (SOD) activities increased initially and then decreased with the increase of concentration in the time gradient, with the largest values at 20 µM. The contents of malondialdehyde (MDA) and proline (Pro) increased with the increase of Hg concentration, both reached peak value at 50 µM. However, chlorophyll (Chl) contents continued to decrease along both the concentration and time gradients. Pearson correlation and principal component analysis showed that two principal components (PC1 and PC2) explained 73.9% of the variance in plant adaptation to Hg stress. SOD, POD, Chl, SS, and Pro all responded well to Hg in S. caninervis. Our study showed that Hg stress caused changes in ultrastructure and physiological metabolism of S. caninervis. 20 µM was the maximum concentration of Hg that biocrust moss S. caninervis can tolerate. S. caninervis mainly adopted two adaptation strategies related to exclusion and accumulation to reduce Hg stress.
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Yang L, Yang H, Bian Z, Lu H, Zhang L, Chen J. The Defensive Role of Endogenous H2S in Brassica rapa against Mercury-Selenium Combined Stress. Int J Mol Sci 2022; 23:ijms23052854. [PMID: 35269996 PMCID: PMC8910845 DOI: 10.3390/ijms23052854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/01/2022] [Accepted: 03/03/2022] [Indexed: 12/14/2022] Open
Abstract
Plants are always exposed to the environment, polluted by multiple trace elements. Hydrogen sulfide (H2S), an endogenous gaseous transmitter in plant cells, can help plant combat single elements with excess concentration. Until now, little has been known about the regulatory role of H2S in response to combined stress of multiple elements. Here we found that combined exposure of mercury (Hg) and selenium (Se) triggered endogenous H2S signal in the roots of Brasscia rapa. However, neither Hg nor Se alone worked on it. In roots upon Hg + Se exposure, the defensive role of endogenous H2S was associated to the decrease in reactive oxygen species (ROS) level, followed by alleviating cell death and recovering root growth. Such findings extend our knowledge of plant H2S in response to multiple stress conditions.
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Affiliation(s)
- Lifei Yang
- Department of Horticulture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (L.Y.); (H.Y.); (Z.B.)
- Hexian New Countryside Development Research Institute, Nanjing Agricultural University, Hexian 238200, China
| | - Huimin Yang
- Department of Horticulture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (L.Y.); (H.Y.); (Z.B.)
| | - Zhiwei Bian
- Department of Horticulture, College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China; (L.Y.); (H.Y.); (Z.B.)
| | - Haiyan Lu
- Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China;
| | - Li Zhang
- Department of Tobacco, College of Plant Protection, Shandong Agricultural University, Taian 271018, China;
| | - Jian Chen
- Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base of Ministry of Science and Technology, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China;
- Correspondence:
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