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Lin H, Ning X, Wang D, Wang Q, Bai Y, Qu J. Quorum-sensing gene regulates hormetic effects induced by sulfonamides in Comamonadaceae. Appl Environ Microbiol 2023; 89:e0166223. [PMID: 38047646 PMCID: PMC10734536 DOI: 10.1128/aem.01662-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 10/17/2023] [Indexed: 12/05/2023] Open
Abstract
IMPORTANCE Antibiotics can induce dose-dependent hormetic effects on bacterial cell proliferation, i.e., low-dose stimulation and high-dose inhibition. However, the underlying molecular basis has yet to be clarified. Here, we showed that sulfonamides play dual roles as a weapon and signal against Comamonas testosteroni that can modulate cell physiology and phenotype. Subsequently, through investigating the hormesis mechanism, we proposed a comprehensive regulatory pathway for the hormetic effects of Comamonas testosteroni low-level sulfonamides and determined the generality of the observed regulatory model in the Comamonadaceae family. Considering the prevalence of Comamonadaceae in human guts and environmental ecosystems, we provide critical insights into the health and ecological effects of antibiotics.
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Affiliation(s)
- Hui Lin
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Science, Beijing, China
| | - Xue Ning
- MaREI Centre, Environmental Research Institute, School of Engineering, University College Cork, Cork, Ireland
| | - Donglin Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Qiaojuan Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Science, Beijing, China
| | - Yaohui Bai
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
| | - Jiuhui Qu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, China
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2
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Sun X, Li P, Zheng G. Biomarker Responses of Spanish Moss Tillandsia usneoides to Atmospheric Hg and Hormesis in This Species. FRONTIERS IN PLANT SCIENCE 2021; 12:625799. [PMID: 33584775 PMCID: PMC7876073 DOI: 10.3389/fpls.2021.625799] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/08/2021] [Indexed: 05/28/2023]
Abstract
Hg is an environmental pollutant with severe biotoxicity. Epiphytic Tillandsia species, especially Spanish moss T. usneoides, are widely used as the bioindicator of Hg pollution. However, the effects of different Hg concentrations on Tillandsia have been rarely studied and the occurrence of hormesis in Tillandsia species has not been determined. In this study, T. usneoides was subjected to stress induced by 15 concentrations of gaseous Hg ranging from 0 to 1.8 μg m-3 through a misting system and then Hg content and eight common biomarkers in leaves were measured. The results showed that leaf Hg content significantly increased with Hg concentration, showing a linear relationship. However, there were no obvious mortality symptoms, indicating that T. usneoides showed strong resistance to Hg. Conversely, there were no simple linear relationships between changes in various biomarkers following Hg treatment of T. usneoides and Hg concentration. With increasing Hg concentration, malondialdehyde (MDA) content did not change significantly, superoxide anion radical content decreased gradually, superoxide dismutase (SOD) content decreased to the bottom and then bounced back, electrical conductivity increased, and glutathione (GSH) and metallothionein (MT) content increased to the peak and then dropped. The coefficient of determination of the dose-effect curves between SOD, GSH, and MT contents and Hg concentration was high, and the dose-effect relationship varied with hormesis. The present study is first to confirm hormesis induced by heavy metal pollution in Tillandsia species.
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Mollaee M, Matloob A, Mobli A, Thompson M, Chauhan BS. Response of glyphosate-resistant and susceptible biotypes of Echinochloa colona to low doses of glyphosate in different soil moisture conditions. PLoS One 2020; 15:e0233428. [PMID: 32433674 PMCID: PMC7239466 DOI: 10.1371/journal.pone.0233428] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 05/05/2020] [Indexed: 11/28/2022] Open
Abstract
To evaluate the hormetic effect of glyphosate on Echinochloa colona, two pot studies were done in the screenhouse at the Gatton Campus, the University of Queensland, Australia. Glyphosate was sprayed at the 3-4 leaf stage using different doses [(0, 5, 10, 20, 40, 80 and 800 g a.e. ha-1) and (0, 2.5, 5, 10, 20 and 800 g a.e. ha-1)] in the first and second study, respectively. In the second study, two soil moistures (adequately-watered and water-stressed), and two E. colona biotypes, glyphosate-resistant and glyphosate-susceptible, were included. In both studies, plants that were treated with glyphosate at 2.5-40 g ha-1 grew taller and produced more leaves, tillers, inflorescences and seeds than the control treatment. In the first study, 5 g ha-1 glyphosate resulted in the maximum aboveground biomass (increase of 34% to 118%) compared with the control treatment. In the second study, the adequately-watered and glyphosate low dose treatments caused an increase in all the measured growth parameters for both biotypes. For example, total dry biomass was increased by 64% and 54% at 5 g ha-1 in the adequately-watered treatments for the resistant and susceptible biotypes, respectively, compared with the control treatment. All measured traits tended to decrease with increasing water stress and the stimulative growth of low doses of glyphosate could not compensate for the water stress effect. The results of both studies showed a hormetic effect of low doses of glyphosate on E. colona biotypes and such growth stimulation was significant in the range of 5 to 10 g ha-1 glyphosate. Water availability was found to be effective in modulating the stimulatory outcomes of glyphosate-induced hormesis. No significant difference was observed between the resistant and susceptible biotypes for hormesis phenomenon. The study showed the importance of precise herbicide application for suppressing weed growth and herbicide resistance evolution.
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Affiliation(s)
- Mahboobeh Mollaee
- Department of Agrotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
- The Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI) and School of Agriculture and Food Sciences (SAFS), The University of Queensland, Gatton, Queensland, Australia
| | - Amar Matloob
- Department of Agronomy, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan
| | - Ahmadreza Mobli
- Department of Agrotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran
- The Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI) and School of Agriculture and Food Sciences (SAFS), The University of Queensland, Gatton, Queensland, Australia
| | - Michael Thompson
- The Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI) and School of Agriculture and Food Sciences (SAFS), The University of Queensland, Gatton, Queensland, Australia
| | - Bhagirath Singh Chauhan
- The Centre for Crop Science, Queensland Alliance for Agriculture and Food Innovation (QAAFI) and School of Agriculture and Food Sciences (SAFS), The University of Queensland, Gatton, Queensland, Australia
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4
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Del Giudice M, Buck CL, Chaby LE, Gormally BM, Taff CC, Thawley CJ, Vitousek MN, Wada H. What Is Stress? A Systems Perspective. Integr Comp Biol 2019; 58:1019-1032. [PMID: 30204874 DOI: 10.1093/icb/icy114] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The term "stress" is used to describe important phenomena at multiple levels of biological organization, but finding a general and rigorous definition of the concept has proven challenging. Current models in the behavioral literature emphasize the cognitive aspects of stress, which is said to occur when threats to the organism are perceived as uncontrollable and/or unpredictable. Here we adopt the perspective of systems biology and take a step toward a general definition of stress by unpacking the concept in light of control theory. Our goal is to clarify the concept so as to facilitate integrative research and formal analysis. We argue that stress occurs when a biological control system detects a failure to control a fitness-critical variable, which may be either internal or external to the organism. Biological control systems typically include both feedback (reactive, compensatory) and feedforward (predictive, anticipatory) components; their interplay accounts for the complex phenomenology of stress in living organisms. The simple and abstract definition we propose applies to animals, plants, and single cells, highlighting connections across levels of organization. In the final section of the paper we explore some extensions of our approach and suggest directions for future research. Specifically, we discuss the classic concepts of conditioning and hormesis and review relevant work on cellular stress responses; show how control theory suggests the existence of fundamental trade-offs in the design of stress responses; and point to potential insights into the effects of novel environmental conditions, including those resulting from anthropogenic change.
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Affiliation(s)
- Marco Del Giudice
- Department of Psychology, University of New Mexico, Logan Hall, 2001 Redondo Dr. NE, Albuquerque, NM 87131, USA
| | - C Loren Buck
- Northern Arizona University, Flagstaff, AZ 86011-0001, USA
| | - Lauren E Chaby
- Wayne State University, 42 W Warren Avenue, Detroit, MI 48202, USA
| | | | - Conor C Taff
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | | | - Maren N Vitousek
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Haruka Wada
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
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5
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Agathokleous E, Anav A, Araminiene V, De Marco A, Domingos M, Kitao M, Koike T, Manning WJ, Paoletti E, Saitanis CJ, Sicard P, Vitale M, Wang W, Calabrese EJ. Commentary: EPA's proposed expansion of dose-response analysis is a positive step towards improving its ecological risk assessment. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 246:566-570. [PMID: 30594897 DOI: 10.1016/j.envpol.2018.12.046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/11/2018] [Accepted: 12/15/2018] [Indexed: 05/17/2023]
Abstract
The United States Environmental Protection Agency (US EPA) has recently proposed changes to strengthen the transparency of its pivotal regulatory science policy and procedures. In this context, the US EPA aims to enhance the transparency of dose-response data and models, proposing to consider for the first time non-linear biphasic dose-response models. While the proposed changes have the potential to lead to markedly improved ecological risk assessment compared to past and current approaches, we believe there remain open issues for improving the quality of ecological risk assessment, such as the consideration of adaptive, dynamic and interactive effects. Improved risk assessment including adaptive and dynamic non-linear models (beyond classic threshold models) can enhance the quality of regulatory decisions and the protection of ecological health. We suggest that other countries consider adopting a similar scientific-regulatory posture with respect to dose-response modeling via the inclusion of non-linear biphasic models, that incorporate the dynamic potential of biological systems to adapt (i.e., enhancing positive biological endpoints) or maladapt to low levels of stressor agents.
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Affiliation(s)
- Evgenios Agathokleous
- Hokkaido Research Center, Forestry and Forest Products Research Institute (FFPRI), Forest Research and Management Organization, 7 Hitsujigaoka, Sapporo, Hokkaido, 062-8516, Japan; Research Faculty of Agriculture, Hokkaido University, Kita 9 Nishi 9, Sapporo, Hokkaido, 060-8589, Japan.
| | - Alessandro Anav
- National Council of Research, Via Madonna del Piano 10, Sesto Fiorentino, Florence, 50019, Italy
| | - Valda Araminiene
- Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Girionys, 53101, Kaunas district, Lithuania
| | - Alessandra De Marco
- Italian National Agency for New Technologies, Energy and the Environment (ENEA), C.R. Casaccia, S. Maria di Galeria, Rome, 00123, Italy
| | - Marisa Domingos
- Instituto de Botânica, Núcleo de Pesquisa em Ecologia, PO Box 68041, 04045-972, SP, Brazil
| | - Mitsutoshi Kitao
- Hokkaido Research Center, Forestry and Forest Products Research Institute (FFPRI), Forest Research and Management Organization, 7 Hitsujigaoka, Sapporo, Hokkaido, 062-8516, Japan
| | - Takayoshi Koike
- Research Faculty of Agriculture, Hokkaido University, Kita 9 Nishi 9, Sapporo, Hokkaido, 060-8589, Japan
| | - William J Manning
- Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA, USA
| | - Elena Paoletti
- National Council of Research, Via Madonna del Piano 10, Sesto Fiorentino, Florence, 50019, Italy
| | - Costas J Saitanis
- Lab of Ecology and Environmental Science, Agricultural University of Athens, Iera Odos 75, Athens, 11855, Greece
| | - Pierre Sicard
- ARGANS, 260 route du Pin Montard, Sophia Antipolis cedex, 06904, France
| | - Marcello Vitale
- Department of Environmental Biology, Sapienza University of Rome, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Wenjie Wang
- Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, 130102, China; Northeast Forestry University, Harbin, 150040, China
| | - Edward J Calabrese
- Department of Environmental Health Sciences, Morrill I, N344, University of Massachusetts, Amherst, MA, 01003, USA
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6
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Pradhan S, Miller L, Marcillo V, Koch AR, Graf Grachet N, Molineros JE, Walker NR, Melouk H, Garzon CD. Hormetic Effects of Thiophanate-Methyl in Multiple Isolates of Sclerotinia homoeocarpa. PLANT DISEASE 2019; 103:89-94. [PMID: 30398944 DOI: 10.1094/pdis-05-18-0872-re] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Twenty-eight isolates of Sclerotinia homoeocarpa, causal agent of dollar spot disease in turf, were assessed for fungicide hormesis at sublethal concentrations of thiophanate-methyl (T-methyl). Each isolate was grown in corn meal agar amended with 11 concentrations of T-methyl (30,500 to 0.047 µg/liter), and the area of mycelial growth was determined relative to the control. Three replicates were used per concentration, and the experiment was repeated three to five times for each isolate. Reference isolates (EC50 > 20 µg/liter), with no prior history of T-methyl exposure, were highly sensitive and not stimulated by low doses. Likewise, no stimulation was observed in two highly sensitive isolates (EC50 > 30 µg/liter) that had been preconditioned by exposure to T-methyl, or in four T-methyl-tolerant isolates. Seventeen (81%) preconditioned T-methyl-tolerant isolates (EC50 = 294 to1,550 µg/liter) had statistically significant growth stimulation, in the range of 2.8 to 19.7% relative to the control. These results support that hormesis (low-dose stimulation, high-dose inhibition) is a common dose response in preconditioned S. homoeocarpa, particularly in response to subtoxic doses of T-methyl.
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Affiliation(s)
- Sumit Pradhan
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater
| | - Lee Miller
- University of Missouri, Division of Plant Sciences, Columbia
| | - Vanessa Marcillo
- GIMA Research Group, Department of Live Sciences and Agriculture, Universidad de las Fuerzas Armadas-ESPE, Sangolquí, Ecuador
| | - Alma R Koch
- GIMA Research Group, Department of Live Sciences and Agriculture, Universidad de las Fuerzas Armadas-ESPE, Sangolquí, Ecuador
| | | | - Julio E Molineros
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater
| | - Nathan R Walker
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater
| | - Hassan Melouk
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater
| | - Carla D Garzon
- Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, and GIMA Research Group, Department of Live Sciences and Agriculture, Universidad de las Fuerzas Armadas-ESPE, Sangolquí, Ecuador
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7
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Dei A. Hormesis and Homeopathy: Toward a New Self-Consciousness. Dose Response 2017; 15:1559325817744451. [PMID: 29225559 PMCID: PMC5714091 DOI: 10.1177/1559325817744451] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 10/17/2017] [Indexed: 12/23/2022] Open
Affiliation(s)
- Andrea Dei
- Department of Chemistry, INSTM Research Unit, University of Florence, Florence, Italy
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8
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How does hormesis impact biology, toxicology, and medicine? NPJ Aging Mech Dis 2017; 3:13. [PMID: 28944077 PMCID: PMC5601424 DOI: 10.1038/s41514-017-0013-z] [Citation(s) in RCA: 273] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 07/13/2017] [Accepted: 08/16/2017] [Indexed: 12/22/2022] Open
Abstract
Hormesis refers to adaptive responses of biological systems to moderate environmental or self-imposed challenges through which the system improves its functionality and/or tolerance to more severe challenges. The past two decades have witnessed an expanding recognition of the concept of hormesis, elucidation of its evolutionary foundations, and underlying cellular and molecular mechanisms, and practical applications to improve quality of life. To better inform future basic and applied research, we organized and re-evaluated recent hormesis-related findings with the intent of incorporating new knowledge of biological mechanisms, and providing fundamental insights into the biological, biomedical and risk assessment implications of hormesis. As the literature on hormesis is expanding rapidly into new areas of basic and applied research, it is important to provide refined conceptualization of hormesis to aid in designing and interpreting future studies. Here, we establish a working compartmentalization of hormesis into ten categories that provide an integrated understanding of the biological meaning and applications of hormesis.
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Mushak P. Temporal stability of chemical hormesis (CH): Is CH just a temporary stop on the road to thresholds and toxic responses? THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:1446-1456. [PMID: 27396315 DOI: 10.1016/j.scitotenv.2016.06.233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 06/23/2016] [Accepted: 06/29/2016] [Indexed: 06/06/2023]
Abstract
Chemical hormesis (CH) is currently described as a nonmonotonic, bidirectional dose-response relationship for chemicals, where a stimulatory, (beneficial?) response at low dose or exposure is followed by an inhibitory response at higher doses/exposures (or vice-versa). CH is depicted as U(J)-shaped or inverse U(J)-shaped curves, i.e., curve slopes change sign. Some describe CH as a homeostasis-preserving response; others view CH as adaptive or (pre)conditioning responses to chemical stress. One aspect of CH and stress hormesis in general that has not been researched is its temporal stability, i.e., persistence, particularly in experimental animals and humans having long-term chemical stressing. Once maximized, does the CH response remain operative over the entire time of chemical exposure? One possible reason for the question's neglect is that temporal stability, e.g., 'steady-state hormesis,' has been assumed. Another is that CH temporality is not well understood or has been under-appreciated as to its importance. Available data, mainly for simpler biological systems, describe cases of transitory CH. Other examples, in human and experimental animal studies, show transitory existence of CH and, in some specialized cases, persisting CH. Also, certain disease state-induced hormetic responses are transitory over time in humans. The question requires resolution if CH is to be considered (i) a stable and beneficial or adverse response, (ii) a stable dose-response model competitive with stable threshold and linear, nonthreshold (LNT) dose-response models, and (iii) a model having any impact on, or role in, regulatory and public health policies.
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Affiliation(s)
- Paul Mushak
- PB Associates, 4036 Nottaway Road, Durham, NC, USA.
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10
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Pradas Del Real AE, García-Gonzalo P, Gil-Díaz MM, González-Rodríguez Á, Lobo C, Pérez-Sanz A. ECO-physiological response of S. vulgaris to CR(VI): Influence of concentration and genotype. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2016; 18:567-574. [PMID: 26375321 DOI: 10.1080/15226514.2015.1086299] [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] [Indexed: 06/05/2023]
Abstract
The objective of this work is to study the response of Silene vulgaris to a range of environmentally relevant concentrations of Cr(VI) in order to evaluate its potential use in the phytomanagement of Cr polluted sites. Cuttings of six homogenous genotypes from Madrid (Spain) have been used as plant material. The eco-physiological response of S. vulgaris to Cr(VI) changed with the genotype. The yield dose-response curve was characterized by stimulation at low doses of Cr(VI). The effects of metal concentration were quantified on root dry weight, water content and chlorophyll content, determined by SPAD index. The response was not homogeneous for all studied genotypes. At high doses of Cr(VI), plants increased micronutrient concentration in dry tissues which suggested that nutrient balance could be implicated in the alleviation of Cr toxicity. This work highlights the importance of studying the eco-physiological response of metallophytes under a range of pollutant concentrations to determine the most favorable traits to be employed in the phytomanagement process.
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Affiliation(s)
- Ana E Pradas Del Real
- a Dpto. de Investigación Agroambiental. IMIDRA , Finca "El Encín" , Alcalá de Henares, Madrid , Spain
| | - Pilar García-Gonzalo
- a Dpto. de Investigación Agroambiental. IMIDRA , Finca "El Encín" , Alcalá de Henares, Madrid , Spain
| | - M Mar Gil-Díaz
- a Dpto. de Investigación Agroambiental. IMIDRA , Finca "El Encín" , Alcalá de Henares, Madrid , Spain
| | - Águeda González-Rodríguez
- a Dpto. de Investigación Agroambiental. IMIDRA , Finca "El Encín" , Alcalá de Henares, Madrid , Spain
| | - Carmen Lobo
- a Dpto. de Investigación Agroambiental. IMIDRA , Finca "El Encín" , Alcalá de Henares, Madrid , Spain
| | - Araceli Pérez-Sanz
- a Dpto. de Investigación Agroambiental. IMIDRA , Finca "El Encín" , Alcalá de Henares, Madrid , Spain
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11
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Affiliation(s)
- SV Jargin
- Peoples’ Friendship University of Russia, Moscow, Russian Federation
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12
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Jargin SV. Hormesis and homeopathy: The artificial twins. JOURNAL OF COMPLEMENTARY MEDICINE RESEARCH 2014; 4:74-7. [PMID: 26401389 PMCID: PMC4566758 DOI: 10.5455/jice.20140929114417] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 09/29/2014] [Indexed: 12/25/2022]
Abstract
Homeopathy claims a curative reaction from small doses of a substance, high doses of which cause symptoms similar to those the patient is suffering from. Hormesis is a concept of biphasic dose-response to different pharmacological and toxicological agents. According to this concept, a small dose of a noxious agent can exert a beneficial action. A hypothesis is defended here that hormesis as a general principle can be assumed only for the factors present in the natural environment thus having induced adaptation of living organisms. Generalizations of the hormesis phenomenon used in support of homeopathy are unfounded. Low-dose impacts may be associated with a higher risk in a state of organ sub-compensation or failure especially in the elderly patients. Practical recommendations should be based neither on the hormesis as a default approach nor on the postulates of homeopathy. All clinically relevant effects, hormetic or not, should be tested by the methods of evidence-based medicine.
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Affiliation(s)
- Sergei V Jargin
- Department of Public Health, Peoples' Friendship University of Russia, Moscow, Russia
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13
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Zhou F, Liang HJ, Di YL, You H, Zhu FX. Stimulatory Effects of Sublethal Doses of Dimethachlon on Sclerotinia sclerotiorum. PLANT DISEASE 2014; 98:1364-1370. [PMID: 30703927 DOI: 10.1094/pdis-10-13-1059-re] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Growth and virulence stimulations of sublethal doses of fungicides on plant-pathogenic fungi and oomycetes have been reported and the stimulatory effects are potentially relevant to plant disease management. Sclerotinia sclerotiorum is one of the most devastating and economically important necrotrophic fungal phytopathogens, capable of infecting more than 400 species of plants worldwide. In order to study stimulatory effects of sublethal doses of fungicides on S. sclerotiorum, 55 dimethachlon-sensitive isolates and 3 dimethachlon-resistant isolates of S. sclerotiorum were assayed to determine effects of sublethal doses of dimethachlon on mycelial growth rate on potato dextrose agar (PDA) media and virulence on oilseed rape plants. Results showed that all 3 dimethachlon-resistant isolates and 13 of the 55 sensitive isolates exhibited stimulatory responses to sublethal doses of dimethachlon. Dimethachlon-resistant isolates grew significantly (P < 0.05) faster on PDA media amended with dimethachlon at 0.5 to 4 μg/ml than on fungicide-free PDA media. As for virulence on detached leaves of oilseed rape plants, lesion diameters of dimethachlon-resistant isolates after growth on PDA media amended with dimethachlon at 0.5 to 2 μg/ml were significantly larger (P < 0.05) than the control. The maximum stimulatory effects were 42.40 to 59.80%. In pot experiments, for both dimethachlon-sensitive and -resistant isolates, significant (P < 0.05) virulence stimulations were observed after spraying with dimethachlon at a concentration of 2 μg/ml. After growing on dimethachlon-amended PDA media, H2O2 sensitivity of S. sclerotiorum decreased significantly (P < 0.05) compared with the nonamended PDA control.
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Affiliation(s)
- Feng Zhou
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong-Jie Liang
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ya-Li Di
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hong You
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Fu-Xing Zhu
- College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
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14
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Belz RG, Duke SO. Herbicides and plant hormesis. PEST MANAGEMENT SCIENCE 2014; 70:698-707. [PMID: 24446388 DOI: 10.1002/ps.3726] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Revised: 01/13/2014] [Accepted: 01/20/2014] [Indexed: 06/03/2023]
Abstract
Herbicide hormesis is commonly observed at subtoxic doses of herbicides and other phytotoxins. The occurrence and magnitude of this phenomenon are influenced by plant growth stage and physiological status, environmental factors, the endpoint measured and the timing between treatment and endpoint measurement. The mechanism in some cases of herbicide hormesis appears to be related to the target site of the herbicide, whereas in other examples hormesis may be by overcompensation to moderate stress induced by the herbicides or a response to disturbed homeostasis. Theoretically, herbicide hormesis could be used in crop production, but this has been practical only in the case of the use of herbicides as sugar cane 'ripeners' to enhance sucrose accumulation. The many factors that can influence the occurrence, the magnitude and the dose range of hormetic increases in yield for most crops make it too unpredictable and risky as a production practice with the currently available knowledge. Herbicide hormesis can cause undesired effects in situations in which weeds are unintentionally exposed to hormetic doses (e.g. in adjacent fields, when shielded by crop vegetation). Some weeds that have evolved herbicide resistance may have hormetic responses to recommended herbicide application rates. Little is known about such effects under field conditions. A more complete understanding of herbicide hormesis is needed to exploit its potential benefits and to minimize its potential harmful effects in crop production.
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Affiliation(s)
- Regina G Belz
- Agroecology Unit, University of Hohenheim, Stuttgart, Germany
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15
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Evaluation of the ecotoxicity of pollutants with bioluminescent microorganisms. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2014; 145:65-135. [PMID: 25216953 DOI: 10.1007/978-3-662-43619-6_3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This chapter deals with the use of bioluminescent microorganisms in environmental monitoring, particularly in the assessment of the ecotoxicity of pollutants. Toxicity bioassays based on bioluminescent microorganisms are an interesting complement to classical toxicity assays, providing easiness of use, rapid response, mass production, and cost effectiveness. A description of the characteristics and main environmental applications in ecotoxicity testing of naturally bioluminescent microorganisms, covering bacteria and eukaryotes such as fungi and dinoglagellates, is reported in this chapter. The main features and applications of a wide variety of recombinant bioluminescent microorganisms, both prokaryotic and eukaryotic, are also summarized and critically considered. Quantitative structure-activity relationship models and hormesis are two important concepts in ecotoxicology; bioluminescent microorganisms have played a pivotal role in their development. As pollutants usually occur in complex mixtures in the environment, the use of both natural and recombinant bioluminescent microorganisms to assess mixture toxicity has been discussed. The main information has been summarized in tables, allowing quick consultation of the variety of luminescent organisms, bioluminescence gene systems, commercially available bioluminescent tests, environmental applications, and relevant references.
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16
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Keim AP, Slis JR, Mendez U, Stroup EM, Burmeister Y, Tsolaki N, Gailing O, Goldman J. The multicomponent medication lymphomyosot improves the outcome of experimental lymphedema. Lymphat Res Biol 2013; 11:81-92. [PMID: 23725444 DOI: 10.1089/lrb.2012.0024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Secondary lymphedema is a life-long disease of painful tissue swelling that often follows axillary lymph node dissection to treat breast cancer. It is hypothesized that poor lymphatic regeneration across the obstructive scar tissue during the wound healing process may predispose the tissue to swell at a later date. Treatment for lymphedema remains suboptimal and is in most cases palliative. The purpose of this study was to evaluate the ability of Lymphomyosot to treat tissue swelling and promote lymphangiogenesis in experimental models of murine lymphedema. METHODS Experimental models of mouse lymphedema were injected with varied amounts of Lymphomyosot and saline as control. Measurements of tail swelling and wound closure were taken and compared amongst the groups. Three separate groups of mice were analyzed for lymphatic capillary migration, lymphatic vessel regeneration, and macrophage recruitment. RESULTS Lymphomyosot significantly reduced swelling and increased the rate of surgical wound closure. Lymphomyosot did not increase the migration of lymph capillaries in a mouse tail skin regeneration model or regeneration of lymph vessels following murine axillary lymph node dissection. CONCLUSIONS Lymphomyosot may act through inflammatory and wound repair pathways to reduce experimental lymphedema. Its ability to regulate inflammation as well as assist in tissue repair and extracellular formation may allow for the production of a scar-free matrix bridge through which migrating cells and accumulated interstitial fluid can freely spread.
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Affiliation(s)
- Alex P Keim
- Department of Biomedical Engineering, Michigan Technological University, Houghton, Michigan, USA
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