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Venzhik Y, Deryabin A, Dykman L. Nanomaterials in plant physiology: Main effects in normal and under temperature stress. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2024; 346:112148. [PMID: 38838991 DOI: 10.1016/j.plantsci.2024.112148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 05/27/2024] [Accepted: 06/01/2024] [Indexed: 06/07/2024]
Abstract
Global climate change and high population growth rates lead to problems of food security and environmental pollution, which require new effective methods to increase yields and stress tolerance of important crops. Nowadays the question of using artificial chemicals is very relevant in theoretical and practical terms. It is important that such substances in low concentrations protect plants under stress conditions, but at the same time inflict minimal damage on the environment and human health. Nanotechnology, which allows the production of a wide range of nanomaterials (NM), provides novel techniques in this direction. NM include structures less than 100 nm. The review presents data on the methods of NM production, their properties, pathways for arrival in plants and their use in human life. It is shown that NM, due to their unique physical and chemical properties, can cross biological barriers and accumulate in cells of live organisms. The influence of NM on plant organism can be both positive and negative, depending on the NM chemical nature, their size and dose, the object of study, and the environmental conditions. This review provides a comparative analysis of the effect of artificial metal nanoparticles (NPm), the commonly employed NMs in plant physiology, on two important aspects of plant life: photosynthetic apparatus activity and antioxidant system function. According to studies, NM affect not only the functional activity of photosynthetic apparatus, but also structural organization of chloroplats. In addition, the literature analysis reflects the dual action of NM on oxidative processes, and antioxidant status of plants. These facts considerably complicate the ideas about possible mechanisms and further use of NPm in biology. In this regard, data on the effects of NM on plants under abiotic stressors are of great interest. Separate section is devoted to the use of NM as adaptogens that increase plant stress tolerance to unfavorable temperatures. Possible mechanisms of NM effects on plants are discussed, as well as the strategies for their further use in basic science and sustainable agriculture.
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Affiliation(s)
- Yliya Venzhik
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia.
| | - Alexander Deryabin
- K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Moscow, Russia
| | - Lev Dykman
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Saratov Scientific Centre of the Russian Academy of Sciences, Saratov, Russia
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2
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Li X, Chen Y, Xu J, Lynch I, Guo Z, Xie C, Zhang P. Advanced nanopesticides: Advantage and action mechanisms. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 203:108051. [PMID: 37820512 DOI: 10.1016/j.plaphy.2023.108051] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/24/2023] [Accepted: 09/20/2023] [Indexed: 10/13/2023]
Abstract
The use of various chemical substances to control pests, diseases, and weeds in the field is a necessary part of the agricultural development process in every country. While the application of pesticides can improve the quality and yield of crops, plant resistance and the harm caused by pesticide residues to the environment and humans have led to the search for greener and safer pesticide formulations to improve the current situation. In recent years, nanopesticides (NPts) have shown great potential in agriculture due to their high efficiency, low toxicity, targeting, resistance, and controlled slow release demonstrated in the experimental stage. Commonly used approaches to prepare NPts include the use of nanoscale metal materials as active ingredients (AI) (ingredients that can play a role in insecticide, sterilization and weeding) or the construction of carriers based on commonly used pesticides to make them stable in nano-sized form. This paper systematically summarizes the advantages and effects of NPts over conventional pesticides, analyzes the formation and functions of NPts in terms of structure, AI, and additives, and describes the mechanism of action of NPts. Despite the feasibility of NPts use, there is not enough comprehensive research on NPts, which must be supplemented by more experiments in terms of biotoxicology and ecological effects to provide strong support for NPts application.
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Affiliation(s)
- Xiaowei Li
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, 255000, Shandong, China
| | - Yiqing Chen
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, 255000, Shandong, China
| | - Jianing Xu
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, 255000, Shandong, China
| | - Iseult Lynch
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Zhiling Guo
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Changjian Xie
- School of Life Sciences and Medicine, Shandong University of Technology, Zibo, 255000, Shandong, China.
| | - Peng Zhang
- Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, 230026, China; School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
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Glavaš Ljubimir K, Domijan AM, Radić Brkanac S. Phytotoxic Action of Silver Nanoparticles on Lemna minor: Multi-Parameter Analysis of Different Physiological Processes. PLANTS (BASEL, SWITZERLAND) 2023; 12:343. [PMID: 36679056 PMCID: PMC9861787 DOI: 10.3390/plants12020343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 12/28/2022] [Accepted: 01/10/2023] [Indexed: 06/17/2023]
Abstract
Considering the widespread use of silver nanoparticles (AgNPs) and their consequent build-up in waterways, there is a concern about the hazardous effect of AgNPs for aquatic ecosystems. The aim of this study was to clarify the mechanism of the action of AgNPs on duckweed (Lemna minor L.) by evaluating multiple parameters in different physiological processes. Duckweed was treated with AgNPs in a concentration range of 0.5 to 5 mg/L over a 7-day period. The analysis revealed that the AgNP-treated duckweed accumulated Ag in accordance with increasing AgNP concentrations. Furthermore, higher concentrations (2 and 5 mg/L) of AgNPs negatively affected N, P and especially K and Mg levels in the plant tissue. Accordingly, the plant growth and photosynthetic parameters were more inhibited in response to higher concentrations of AgNPs. Nanosilver significantly increased the generation of ROS at higher concentrations, although lipid peroxidation was significant even at the lowest concentration of AgNPs. However, defense mechanisms were able to counteract AgNP-induced oxidative stress and balance the intracellular redox status, as evidenced by increased activities of the main detoxification enzymes. With this experimental setting, AgNPs exhibited a relatively weak phytotoxicity at 0.5 and 1 mg/L; nevertheless, silver in a nano form poses a hazard for plants, considering its continuous release into aquatic environments.
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Affiliation(s)
| | - Ana-Marija Domijan
- Department of Pharmaceutical Botany, Faculty of Pharmacy and Biochemistry, University of Zagreb, 10 000 Zagreb, Croatia
| | - Sandra Radić Brkanac
- Department of Biology, Faculty of Science, University of Zagreb, 10 000 Zagreb, Croatia
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Aqeel U, Aftab T, Khan MMA, Naeem M, Khan MN. A comprehensive review of impacts of diverse nanoparticles on growth, development and physiological adjustments in plants under changing environment. CHEMOSPHERE 2022; 291:132672. [PMID: 34756946 DOI: 10.1016/j.chemosphere.2021.132672] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 10/12/2021] [Accepted: 10/23/2021] [Indexed: 06/13/2023]
Abstract
The application of nanotechnology in agriculture includes the use of nanofertilizers, nanopesticides, and nanoherbicides that enhance plant nutrition without disturbing the soil texture and protect it against microbial infections. Thus, nanotechnology maintains the plant's health by maintaining its soil health. The use of nanoparticles (NPs) in agriculture reduces the chemical spread and nutrient loss and boosts crop yield and productivity. Effect of NPs varies with their applied concentrations, physiochemical properties, and plant species. Various NPs have an impact on the plant to increase biomass productivity, germination rate and their physiology. Also, NPs change the plant molecular mechanisms by altering gene expression. Metal and non-metal oxides of NPs (Au, Ag, ZnO, Fe2O3, TiO2, SiO2, Al2O3, Se, carbon nanotubes, quantum dots) exert an important role in plant growth and development and perform an essential role in stress amelioration. On the other hand, other effects of NPs have also been well investigated by observing their role in growth suppression and inhibition of chlorophyll and photosynthetic efficiency. In this review, we addressed a description of studies that have been made to understand the effects of various kind of NPs, their translocation and interaction with the plants. Also, the phytoremediation approaches of contaminated soil with combined use of NPs for sustainable agriculture is covered.
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Affiliation(s)
- Umra Aqeel
- Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh, 202002, India
| | - Tariq Aftab
- Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh, 202002, India
| | - M Masroor A Khan
- Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh, 202002, India
| | - M Naeem
- Plant Physiology Section, Department of Botany, Aligarh Muslim University, Aligarh, 202002, India.
| | - M Nasir Khan
- Department of Biology, Faculty of Science, College of Haql, University of Tabuk, Tabuk, Saudi Arabia
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Venzhik YV, Moshkov IE, Dykman LA. Influence of Nanoparticles of Metals and Their Oxides on the Photosynthetic Apparatus of Plants. BIOL BULL+ 2021. [DOI: 10.1134/s106235902102014x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Peharec Štefanić P, Košpić K, Lyons DM, Jurković L, Balen B, Tkalec M. Phytotoxicity of Silver Nanoparticles on Tobacco Plants: Evaluation of Coating Effects on Photosynthetic Performance and Chloroplast Ultrastructure. NANOMATERIALS 2021; 11:nano11030744. [PMID: 33809644 PMCID: PMC8002358 DOI: 10.3390/nano11030744] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/05/2021] [Accepted: 03/11/2021] [Indexed: 12/11/2022]
Abstract
Silver nanoparticles (AgNPs) are the most exploited nanomaterial in agriculture and food production, and their release into the environment raises concern about their impact on plants. Since AgNPs are prone to biotransformation, various surface coatings are used to enhance their stability, which may modulate AgNP-imposed toxic effects. In this study, the impact of AgNPs stabilized with different coatings (citrate, polyvinylpyrrolidone (PVP), and cetyltrimethylammonium bromide (CTAB)) and AgNO3 on photosynthesis of tobacco plants as well as AgNP stability in exposure medium have been investigated. Obtained results revealed that AgNP-citrate induced the least effects on chlorophyll a fluorescence parameters and pigment content, which could be ascribed to their fast agglomeration in the exposure medium and consequently weak uptake. The impact of AgNP-PVP and AgNP-CTAB was more severe, inducing a deterioration of photosynthetic activity along with reduced pigment content and alterations in chloroplast ultrastructure, which could be correlated to their higher stability, elevated Ag accumulation, and surface charge. In conclusion, intrinsic properties of AgNP coatings affect their stability and bioavailability in the biological medium, thereby indirectly contributing changes in the photosynthetic apparatus. Moreover, AgNP treatments exhibited more severe inhibitory effects compared to AgNO3, which indicates that the impact on photosynthesis is dependent on the form of Ag.
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Affiliation(s)
- Petra Peharec Štefanić
- Department of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia; (P.P.Š.); (K.K.); (B.B.)
| | - Karla Košpić
- Department of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia; (P.P.Š.); (K.K.); (B.B.)
| | - Daniel Mark Lyons
- Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, 52210 Rovinj, Croatia; (D.M.L.); (L.J.)
| | - Lara Jurković
- Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, 52210 Rovinj, Croatia; (D.M.L.); (L.J.)
| | - Biljana Balen
- Department of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia; (P.P.Š.); (K.K.); (B.B.)
| | - Mirta Tkalec
- Department of Biology, Faculty of Science, University of Zagreb, Horvatovac 102a, HR-10000 Zagreb, Croatia; (P.P.Š.); (K.K.); (B.B.)
- Correspondence:
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Ziegler P, Sree KS, Appenroth KJ. Duckweed biomarkers for identifying toxic water contaminants? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:14797-14822. [PMID: 30397749 DOI: 10.1007/s11356-018-3427-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
Surface or ground waters can be contaminated with numerous toxic substances. The duckweeds Lemna minor and Lemna gibba are widely used for assaying waterborne toxicity to higher plants in terms of growth inhibition and photosynthetic pigment reduction. These tests cannot, however, in themselves determine the nature of the agents responsible for toxicity. Morphological, developmental, physiological, biochemical, and genetic responses of duckweeds to exposure to toxic water contaminants constitute biomarkers of toxic effect. In principle, the very detection of these biomarkers should enable the contaminants having elicited them (and being responsible for the toxicity) to be identified. However, in practice, this is severely compromised by insufficient specificity of biomarkers for their corresponding toxicants and by the lack of documentation of biomarker/toxin relationships. The present contribution illustrates the difficulties of using known water contaminant-related duckweed biomarkers to identify toxins, and discusses possibilities for achieving this goal.
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Affiliation(s)
- Paul Ziegler
- Department of Plant Physiology, University of Bayreuth, Universitätsstr. 30, 95440, Bayreuth, Germany.
| | - Kandregula Sowjanya Sree
- Department of Environmental Science, Central University of Kerala, Tejaswini Hills, Periye, 671316, India
| | - Klaus-Jürgen Appenroth
- Matthias-Schleiden Institute, Department of Plant Physiology, Friedrich-Schiller-University Jena, Dornburger Str. 159, 07743, Jena, Germany
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Tighe-Neira R, Carmora E, Recio G, Nunes-Nesi A, Reyes-Diaz M, Alberdi M, Rengel Z, Inostroza-Blancheteau C. Metallic nanoparticles influence the structure and function of the photosynthetic apparatus in plants. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2018; 130:408-417. [PMID: 30064097 DOI: 10.1016/j.plaphy.2018.07.024] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/17/2018] [Accepted: 07/18/2018] [Indexed: 06/08/2023]
Abstract
The applications of nanoparticles continue to expand into areas as diverse as medicine, bioremediation, cosmetics, pharmacology and various industries, including agri-food production. The widespread use of nanoparticles has generated concerns given the impact these nanoparticles - mostly metal-based such as CuO, Ag, Au, CeO2, TiO2, ZnO, Co, and Pt - could be having on plants. Some of the most studied variables are plant growth, development, production of biomass, and ultimately oxidative stress and photosynthesis. A systematic appraisal of information about the impact of nanoparticles on these processes is needed to enhance our understanding of the effects of metallic nanoparticles and oxides on the structure and function on the plant photosynthetic apparatus. Most nanoparticles studied, especially CuO and Ag, had a detrimental impact on the structure and function of the photosynthetic apparatus. Nanoparticles led to a decrease in concentration of photosynthetic pigments, especially chlorophyll, and disruption of grana and other malformations in chloroplasts. Regarding the functions of the photosynthetic apparatus, nanoparticles were associated with a decrease in the photosynthetic efficiency of photosystem II and decreased net photosynthesis. However, CeO2 and TiO2 nanoparticles may have a positive effect on photosynthetic efficiency, mainly due to an increase in electron flow between the photosystems II and I in the Hill reaction, as well as an increase in Rubisco activity in the Calvin and Benson cycle. Nevertheless, the underlying mechanisms are poorly understood. The future mechanistic work needs to be aimed at characterizing the enhancing effect of nanoparticles on the active generation of ATP and NADPH, carbon fixation and its incorporation into primary molecules such as photo-assimilates.
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Affiliation(s)
- Ricardo Tighe-Neira
- Programa de Doctorado en Ciencias Agropecuarias, Facultad de Recursos Naturales, Universidad Católica de Temuco, P.O. Box 15-D, Temuco, Chile; Departamento de Ciencias Agropecuarias y Acuícolas, Facultad de Recursos Naturales, Universidad Católica de Temuco, P.O. Box 15-D, Temuco, Chile
| | - Erico Carmora
- Núcleo de Investigación en Bioproductos y Materiales Avanzados, Facultad de Ingeniería, Universidad Católica de Temuco, P.O. Box 15-D, Temuco, Chile
| | - Gonzalo Recio
- Núcleo de Investigación en Bioproductos y Materiales Avanzados, Facultad de Ingeniería, Universidad Católica de Temuco, P.O. Box 15-D, Temuco, Chile
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Minas Gerais, 36570-900, Viçosa, Brazil
| | - Marjorie Reyes-Diaz
- Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería y Ciencias, Universidad de La Frontera, P.O. Box 54-D, Temuco, Chile; Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, P.O. Box 54-D, Temuco, Chile
| | - Miren Alberdi
- Departamento de Ciencias Químicas y Recursos Naturales, Facultad de Ingeniería y Ciencias, Universidad de La Frontera, P.O. Box 54-D, Temuco, Chile; Center of Plant, Soil Interaction and Natural Resources Biotechnology, Scientific and Technological Bioresource Nucleus (BIOREN), Universidad de La Frontera, P.O. Box 54-D, Temuco, Chile
| | - Zed Rengel
- Soil Science and Plant Nutrition, UWA School of Agriculture and Environment, The University of Western Australia, Perth, WA, 6009, Australia
| | - Claudio Inostroza-Blancheteau
- Departamento de Ciencias Agropecuarias y Acuícolas, Facultad de Recursos Naturales, Universidad Católica de Temuco, P.O. Box 15-D, Temuco, Chile; Núcleo de Investigación en Producción Alimentaria, Facultad de Recursos Naturales, Universidad Católica de Temuco, P.O. Box 15-D, Temuco, Chile.
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Pardha-Saradhi P, Shabnam N, Sharmila P, Ganguli AK, Kim H. Differential sensitivity of light-harnessing photosynthetic events in wheat and sunflower to exogenously applied ionic and nanoparticulate silver. CHEMOSPHERE 2018; 194:340-351. [PMID: 29220750 DOI: 10.1016/j.chemosphere.2017.11.122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 11/19/2017] [Accepted: 11/22/2017] [Indexed: 06/07/2023]
Abstract
Potential impacts of inevitable leaks of silver nanoparticles (AgNPs) into environment on human beings need attention. Owing to the vitality of photosynthesis in maintaining life and ecosystem functioning, impacts of exogenously applied nanoparticulate and Ag+ on photosystem (PS)II function, which governs overall photosynthesis, in wheat and sunflower were evaluated. PSII efficiency and related Chl a fluorescence kinetics of these two plants remained unaffected by AgNPs. However, Ag+ caused a significant decline in the PSII activity and related fluorescence steps in wheat, but not in sunflower. Electron flow between QA and PQ pool was found most sensitive to Ag+. Number of active reaction centers, electron transport, trapping of absorbed light for photochemistry, and performance index declined, while dissipation of absorbed light energy as heat significantly increased in wheat exposed to Ag+. Total antioxidant activity in sunflower was least affected by both Ag and AgNPs. In contrast, in the case of wheat, the antioxidant activity was declined by Ag+ but not by AgNPs. Further, the amount of silver absorbed by plants exposed to Ag+ was higher than that absorbed by plants exposed to AgNPs. While wheat retained majority of Ag in its roots, sunflower showed major Ag accumulation in stem. Photosynthetic events in sunflower, unlike wheat, were least affected as no detectable Ag levels was recorded in their leaves. Our findings revealed that AgNPs seemed non/less-toxic to light harnessing photosynthetic machinery of wheat, compared to Ag+. Photosynthetic events in sunflower were not affected by Ag+, either, as its translocation to leaves was restricted.
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Affiliation(s)
- P Pardha-Saradhi
- Department of Environmental Studies, University of Delhi, Delhi, 110007, India.
| | - Nisha Shabnam
- Department of Environmental Engineering, University of Seoul, Seoul, 02504, South Korea
| | - P Sharmila
- Department of Chemistry, Indian Institute of Technology, New Delhi, 110016, India
| | - Ashok K Ganguli
- Department of Chemistry, Indian Institute of Technology, New Delhi, 110016, India; Institute of Nanoscience and Technology, Habitat Centre, Phase-X, Sector-64, Mohali, 160062, Punjab, India
| | - Hyunook Kim
- Department of Environmental Engineering, University of Seoul, Seoul, 02504, South Korea.
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Shabnam N, Sharmila P, Govindjee, Kim H, Pardha-Saradhi P. Differential Response of Floating and Submerged Leaves of Longleaf Pondweed to Silver Ions. FRONTIERS IN PLANT SCIENCE 2017; 8:1052. [PMID: 28680432 PMCID: PMC5478881 DOI: 10.3389/fpls.2017.01052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 05/31/2017] [Indexed: 11/13/2023]
Abstract
In this study, we have investigated variations in the potential of floating and submerged leaves of longleaf pondweed (Potamogeton nodosus) to withstand silver ion (Ag+)-toxicity. Both floating and submerged leaves changed clear colorless AgNO3 solutions to colloidal brown in the presence of light. Transmission electron microscopy revealed the presence of distinct crystalline Ag-nanoparticles (Ag-NPs) in these brown solutions. Powder X-ray diffraction pattern showed that Ag-NPs were composed of Ag0 and Ag2O. Photosystem (PS) II efficiency of leaves declined upon exposure to Ag+ with a significantly higher decline in the submerged leaves than in the floating leaves. Similarly, Ag+ treatment caused a significant reduction in the carboxylase activity of the ribulose bisphosphate carboxylase/oxygenase in leaves. The reduction in this carboxylase activity was significantly higher in the submerged than in the floating leaves. Ag+ treatment also resulted in a significant decline in the levels of non-enzymatic and enzymatic antioxidants; the decline was significantly lower in the floating than in submerged leaves. X-ray photoelectron spectroscopy revealed the presence of Ag2O in these leaves. Inductively coupled plasma mass spectrometry analysis revealed a three-fold higher Ag content in the submerged than in floating leaves. Our study demonstrates that floating leaves of longleaf pondweed have a superior potential to counter Ag+-toxicity compared with submerged leaves, which could be due to superior potential of floating leaves to reduce Ag+ to less/non-toxic Ag0/Ag2O-nanoparticles/nanocomplexes. We suggest that modulating the genotype of longleaf pondweed to bear higher proportion of floating leaves would help in cleaning fresh water bodies contaminated with ionic forms of heavy metals.
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Affiliation(s)
- Nisha Shabnam
- Department of Energy and Environmental System Engineering, University of SeoulSeoul, South Korea
| | - P. Sharmila
- Department of Chemistry, Indian Institute of Technology DelhiNew Delhi, India
| | - Govindjee
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, UrbanaIL, United States
| | - Hyunook Kim
- Department of Energy and Environmental System Engineering, University of SeoulSeoul, South Korea
| | - P. Pardha-Saradhi
- Department of Environmental Studies, University of DelhiNew Delhi, India
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