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Gerstle V, Bollinger E, Manfrin A, Pietz S, Kolbenschlag S, Feckler A, Entling MH, Brühl CA. Trophic effects of Bti-based mosquito control on two top predators in floodplain pond mesocosms. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024:10.1007/s11356-024-34124-w. [PMID: 38967849 DOI: 10.1007/s11356-024-34124-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Accepted: 06/21/2024] [Indexed: 07/06/2024]
Abstract
Chironomid (Diptera: Chironomidae) larvae play a key role in aquatic food webs as prey for predators like amphibian and dragonfly larvae. This trophic link may be disrupted by anthropogenic stressors such as Bacillus thuringiensis var. israelensis (Bti), a biocide widely used in mosquito control. In a companion study, we recorded a 41% reduction of non-target larval chironomids abundance in outdoor floodplain pond mesocosms (FPMs) treated with Bti. Therefore, we examined the diet of two top predators in the FPMs, larvae of the palmate newt (Salamandridae: Lissotriton helveticus) and dragonfly (Aeshnidae: predominantly Anax imperator), using bulk stable isotope analyses of carbon and nitrogen. Additionally, we determined neutral lipid fatty acids in newt larvae to assess diet-related effects on their physiological condition. We did not find any effects of Bti on the diet proportions of newt larvae and no significant effects on the fatty acid content. We observed a trend in Aeshnidae larvae from Bti-FPMs consuming a higher proportion of large prey (Aeshnidae, newt, damselfly larvae; ~42%), and similar parts of smaller prey (chironomid, mayfly, Libellulidae, and zooplankton), compared to controls. Our findings may suggest bottom-up effects of Bti on aquatic predators but should be further evaluated, for instance, by using compound-specific stable isotope analyses of fatty acids or metabarcoding approaches.
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Affiliation(s)
- Verena Gerstle
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany.
- Eußerthal Ecosystem Research Station, RPTU Kaiserslautern-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany.
| | - Eric Bollinger
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Alessandro Manfrin
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Sebastian Pietz
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Sara Kolbenschlag
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Alexander Feckler
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
- Eußerthal Ecosystem Research Station, RPTU Kaiserslautern-Landau, Birkenthalstraße 13, D-76857, Eußerthal, Germany
| | - Martin H Entling
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
| | - Carsten A Brühl
- Institute for Environmental Sciences, iES Landau, RPTU Kaiserslautern-Landau, Fortstraße 7, D-76829, Landau, Germany
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Eigharlou M, Hashemi Z, Mohammadi A, Khelghatibana F, Nami Y, Sadeghi A. Herbicidal proteins from Bacillus wiedmannii isolate ZT selectively inhibit ryegrass (Lolium temulentum L.). PEST MANAGEMENT SCIENCE 2024; 80:3478-3490. [PMID: 38426586 DOI: 10.1002/ps.8053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 01/16/2024] [Accepted: 03/01/2024] [Indexed: 03/02/2024]
Abstract
BACKGROUND The widespread use of chemical herbicides and the growing issue of weed resistance pose significant challenges in agriculture. To address these problems, there is a pressing need to develop biological herbicides based on bacterial metabolites. RESULTS In this study, we investigated the impact of the cell-free culture filtrate (CFCF) from the ZT isolate, a bacilliform bacterium obtained from diseased wheat seeds, on the germination and seedling growth of various plant species, including wild oat, ryegrass, redroot, wheat, and chickpea. The results revealed that CFCF had a detrimental effect on the fresh and dry weight of stems and roots in most of the studied plants, except chickpeas. The CFCF was further subjected to separation into aqueous and organic phases using chloroform, followed by the division of the aqueous phase into 13 fractions using an alumina column. Notably, both the aqueous phase (20%) and all 13 fractions (ranging from 50% to 83%) displayed the ability to reduce the root length of ryegrass, a monocotyledonous weed. Liquid chromatography-mass spectrometry (LC-MS) analysis identified that fractions 3 and 7, which were effective against ryegrass but not redroot, contained Cry family proteins, including Cry10 Aa, Cry4 Ba, and Cry4 Aa. Additionally, 16s rRNA gene sequencing revealed that the ZT isolate is closely related (98.27%) to Bacillus wiedmannii. CONCLUSION Conclusively, metabolites from the ZT bacterium hold promise for monocotyledonous weed-targeted herbicides, providing a constructive strategy to confront agricultural issues tied to chemical herbicides and weed resistance. © 2024 Society of Chemical Industry.
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Affiliation(s)
- Mahsa Eigharlou
- Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
- Department of Microbiology, School of Biology and Pharmaceutical Biotechnology Lab, College of Science, Tehran University, Tehran, Iran
| | - Zeinabalsadat Hashemi
- Department of Microbial Biotechnology, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Ali Mohammadi
- Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran
| | - Fatemeh Khelghatibana
- Plant Pathology Department, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
| | - Yousef Nami
- Department of Food Biotechnology, Branch for Northwest and West Region, Agricultural Biotechnology Research, Institute of Iran, Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
| | - Akram Sadeghi
- Department of Microbial Biotechnology, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
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Rajan V. Reply to Berry, C. Factors Related to Bacillus thuringiensis and Gut Physiology. Comment on "Rajan, V. An Alkaline Foregut Protects Herbivores from Latex in Forage, but Increases Their Susceptibility to Bt Endotoxin. Life 2023, 13, 2195". Life (Basel) 2024; 14:207. [PMID: 38398715 PMCID: PMC10890157 DOI: 10.3390/life14020207] [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: 01/03/2024] [Accepted: 01/29/2024] [Indexed: 02/25/2024] Open
Abstract
The comment titled "Factors related to Bacillus thuringiensis and gut physiology" disputes some of the inferences in the paper "An Alkaline Foregut Protects Herbivores from Latex in Forage, but Increases Their Susceptibility to Bt Endotoxin" published in this journal. The key points in the dissent are the following: 1. Bt is generally safe to non-target species. 2. Transgenic Bt crops provide additional ecological benefits due to reductions in conventional pesticide use. 3. Susceptibility to Bt does not indicate alkalinity, nor vice versa. My response is summarized as follows: 1. Bt can form non-specific pores at concentrations of 100 ng/mL in culture, and so is potentially unsafe for animals with gut environments in which Bt persists at or above this level. 2. Initial reductions in insecticide applications have not been sustained and are even increasing in areas planted with transgenic Bt cotton. 3. Acidic guts degrade Bt more efficiently, but I concede that gut alkalinity does not imply susceptibility to Bt due to many factors including resistance in target species, toxin heterogeneity and variable modes of action. However, the susceptibility of foregut-fermenting herbivores with alkaline guts to Bt intoxication cannot be invalidated without further study.
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Affiliation(s)
- Vidya Rajan
- Department of Medical and Molecular Sciences, University of Delaware, Newark, DE 19716, USA
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Čėsna V, Čėsnienė I, Sirgedaitė-Šėžienė V, Marčiulynienė D. Changes in Biologically Active Compounds in Pinus sylvestris Needles after Lymantria monacha Outbreaks and Treatment with Foray 76B. PLANTS (BASEL, SWITZERLAND) 2024; 13:328. [PMID: 38276785 PMCID: PMC10821276 DOI: 10.3390/plants13020328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/16/2024] [Accepted: 01/20/2024] [Indexed: 01/27/2024]
Abstract
Due to climate warming, the occurrence of Lymantria monacha outbreaks is predicted to become more frequent, causing repeated and severe damage to conifer trees. Currently, the most effective way to control the outbreaks is aerial spraying with the bioinsecticide Foray 76B. The present study aimed to determine the impact of both: (i) L. monacha outbreaks and (ii) treatment with Foray 76B on tree resistance through the synthesis of polyphenols (TPC), flavonoids (TFC), photosynthetic pigments (chlorophyll a and b, carotenoids), lipid peroxidation (MDA), and soluble sugars (TSS) in Pinus sylvestris needles. Samples were collected from visually healthy (control), damaged/untreated, and damaged/Foray 76B-treated plots in 2020 and 2021 (following year after the outbreaks). The results revealed that L. monacha outbreaks contributed to the increase in TPC by 34.1% in 2020 and 26.7% in 2021. TFC negatively correlated with TPC, resulting in 17.6% and 11.1% lower concentrations in L. monacha-damaged plots in 2020 and 2021, respectively. A decrease in MDA was found in the damaged plots in both 2020 and 2021 (10.2% and 23.3%, respectively), which was associated with the increased synthesis of photosynthetic pigments in 2021. The research results also showed that in the following year after the outbreaks, the increase in the synthesis of photosynthetic pigments was also affected by the treatment with Foray 76B. Moreover, the increase in the synthesis of TPC and photosynthetic pigments in the damaged plots in 2021 illustrates the ability of pines to keep an activated defense system to fight biotic stress. Meanwhile, a higher synthesis of photosynthetic pigments in Foray 76B-treated plots indicates a possible effect of the treatment on faster tree growth and forest recovery after L. monacha outbreaks.
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Affiliation(s)
- Vytautas Čėsna
- Institute of Forestry, Lithuanian Research Centre for Agriculture and Forestry, Liepų 1, Girionys, LT-53101 Kaunas, Lithuania; (I.Č.); (V.S.-Š.); (D.M.)
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de Oliveira Dorta S, Attílio LB, Zanardi OZ, Lopes JRS, Machado MA, Freitas-Astúa J. Genetic transformation of 'Hamlin' and 'Valencia' sweet orange plants expressing the cry11A gene of Bacillus thuringiensis as another tool to the management of Diaphorina citri (Hemiptera: Liviidae). J Biotechnol 2023; 368:60-70. [PMID: 37088156 DOI: 10.1016/j.jbiotec.2023.04.007] [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: 12/30/2022] [Revised: 03/29/2023] [Accepted: 04/20/2023] [Indexed: 04/25/2023]
Abstract
The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama (Hemiptera: Liviidae) is the vector of Candidatus Liberibacter spp., the bacteria associated with huanglongbing (HLB), the most devastating disease of citrus worldwide. HLB management has heavily counted on insecticide applications to control the ACP, although there are efforts towards more sustainable alternatives. In previous work, our group assessed the potential bioactivity of different strains of Bacillus thuringiensis (Eubacteriales: Bacillaceae) (Bt) containing cry/cyt genes as feasible tools to control ACP nymphs. Here, we report an attempt to use the cry11A gene from Bt to produce transgenic sweet orange plants using two promoters. For the genetic transformation, 'Hamlin' and 'Valencia' sweet orange seedlings were used as sources of explants. Transgenic plants were detected by polymerase chain reaction (PCR) with specific primers, and the transgene copy number was confirmed by Southern blot analyses. Transcript expression levels were determined by qPCR. Mortality assays of D. citri nymphs were carried out in a greenhouse, and the effect of the events tested ranged from 22 to 43% at the end of the five-day exposure period. To our knowledge, this is the first manuscript reporting the production of citrus plants expressing the Bt cry11A gene for the management of D. citri nymphs.
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Affiliation(s)
- Sílvia de Oliveira Dorta
- Programa de Pós-Graduação em Microbiologia Agrícola, Escola Superior de Agricultura Luiz de Queiroz/Universidade de São Paulo (ESALQ/USP), 13.418-900, Piracicaba, São Paulo, Brazil; Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas (IAC), 13.490-970, Cordeirópolis, São Paulo, Brazil.
| | - Lísia Borges Attílio
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas (IAC), 13.490-970, Cordeirópolis, São Paulo, Brazil; Laboratório de Insetos Vetores de Fitopatógenos, Escola Superior de Agricultura Luiz de Queiroz/Universidade de São Paulo (ESALQ/USP), 13.418-900, Piracicaba, São Paulo, Brazil
| | - Odimar Zanuzo Zanardi
- Departamento de Ensino, Pesquisa e Extensão, Instituto Federal de Santa Catarina (IFSC), 89.900-000, São Miguel do Oeste, Santa Catarina, Brasil
| | - João Roberto Spotti Lopes
- Laboratório de Insetos Vetores de Fitopatógenos, Escola Superior de Agricultura Luiz de Queiroz/Universidade de São Paulo (ESALQ/USP), 13.418-900, Piracicaba, São Paulo, Brazil
| | - Marcos Antonio Machado
- Laboratório de Biotecnologia, Centro de Citricultura Sylvio Moreira, Instituto Agronômico de Campinas (IAC), 13.490-970, Cordeirópolis, São Paulo, Brazil
| | - Juliana Freitas-Astúa
- Embrapa Mandioca e Fruticultura, 44.380-000, Cruz das Almas, Bahia, Brazil; Unidade Laboratorial de Referência em Biologia Molecular Aplicada/Instituto Biológico (ULRBMA/IB), 04.014-900, São Paulo, São Paulo, Brazil.
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Grizanova EV, Krytsyna TI, Kalmykova GV, Sokolova E, Alikina T, Kabilov M, Coates CJ, Dubovskiy IM. Virulent and necrotrophic strategies of Bacillus thuringiensis in susceptible and resistant insects, Galleria mellonella. Microb Pathog 2023; 175:105958. [PMID: 36572197 DOI: 10.1016/j.micpath.2022.105958] [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: 10/11/2022] [Revised: 12/03/2022] [Accepted: 12/21/2022] [Indexed: 12/25/2022]
Abstract
Bacillus thuringiensis (Bt) is one of the most common entomopathogenic bacteria used as a biopesticide, and source of endotoxin genes for generating insect-resistant transgenic plants. The mechanisms underpinning an insect's susceptibility or resistance to B. thuringiensis are diverse. The bacterial lifecycle does not end with the death of a host, they continue to exploit the cadaver to reproduce and sporulate. Herein, we studied the progression of B. thuringiensis subsp. galleriae infection in two populations of wax moth larvae (Galleria mellonella) to gain further insight into the "arms race" between B. thuringiensis virulence and insect defences. Two doses of B. thuringiensis subsp. galleriae (spore and crystalline toxin mixtures) were administered orally to compare the responses of susceptible (S) and resistant (R) populations at ∼30% mortality each. To investigate B. thuringiensis-insect antibiosis, we used a combination of in vivo infection trials, bacterial microbiome analysis, and RNAi targeting the antibacterial peptide gloverin. Within 48 h post-inoculation, B. thuringiensis-resistant insects purged the midgut of bacteria, i.e., colony forming unit numbers fell below detectable levels. Second, B. thuringiensis rapidly modulated gene expression to initiate sporulation (linked to quorum sensing) when exposed to resistant insects in contrast to susceptible G. mellonella. We reinforce earlier findings that elevated levels of antimicrobial peptides, specifically gloverin, are found in the midgut of resistant insects, which is an evolutionary strategy to combat B. thuringiensis infection via its main portal of entry. A sub-population of highly virulent B. thuringiensis can survive the enhanced immune defences of resistant G. mellonella by disrupting the midgut microbiome and switching rapidly to a necrotrophic strategy, prior to sporulation in the cadaver.
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Affiliation(s)
- Ekaterina V Grizanova
- Department of Plant Protection, Novosibirsk State Agrarian University, 630039, Novosibirsk, Russia.
| | - Tatiana I Krytsyna
- Department of Plant Protection, Novosibirsk State Agrarian University, 630039, Novosibirsk, Russia.
| | - Galina V Kalmykova
- Faculty of Physical Engineering, Novosibirsk State Technical University, 630039, Novosibirsk, Russia.
| | - Elina Sokolova
- Department of Plant Protection, Novosibirsk State Agrarian University, 630039, Novosibirsk, Russia.
| | - Tatyana Alikina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630039, Novosibirsk, Russia.
| | - Marsel Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630039, Novosibirsk, Russia.
| | - Christopher J Coates
- Zoology, Ryan Institute, School of Natural Sciences, University of Galway, Galway, H91 TK33, Ireland; Department of Biosciences, Faculty of Science and Engineering, Swansea University, Swansea, SA2 8PP, Wales, UK.
| | - Ivan M Dubovskiy
- Department of Plant Protection, Novosibirsk State Agrarian University, 630039, Novosibirsk, Russia.
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Kolbenschlag S, Gerstle V, Eberhardt J, Bollinger E, Schulz R, Brühl CA, Bundschuh M. A temporal perspective on aquatic subsidy: Bti affects emergence of Chironomidae. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 250:114503. [PMID: 36610297 DOI: 10.1016/j.ecoenv.2023.114503] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 11/05/2022] [Accepted: 01/02/2023] [Indexed: 06/17/2023]
Abstract
Emerging aquatic insects serve as one link between aquatic and adjacent riparian food webs via the flux of energy and nutrients. These insects provide high-quality subsidy to terrestrial predators. Thus, any disturbance of emergence processes may cascade to higher trophic levels and lead to effects across ecosystem boundaries. One stressor with potential impact on non-target aquatic insects, especially on non-biting midges (Diptera: Chironomidae), is the widely used mosquito control agent Bacillus thuringiensis var. israelensis (Bti). In a field experiment, we investigated emerging insect communities from Bti-treated (three applications, maximum field rate) and control floodplain pond mesocosms (FPMs) over 3.5 months for changes in their composition, diversity as well as the emergence dynamics and the individual weight of emerged aquatic insects over time. Bti treatments altered community compositions over the entire study duration - an effect mainly attributed to an earlier (∼10 days) and reduced (∼26%) peak in the emergence of Chironomidae, the dominant family (88% of collected individuals). The most reasonable explanation for this significant alteration is less resource competition caused by a decrease in chironomid larval density due to lethal effects of Bti. This is supported by the higher individual weight of Chironomidae emerging from treated FPMs (∼21%) during Bti application (April - May). A temporal shift in the emergence dynamics can cause changes in the availability of prey in linked terrestrial ecosystems. Consequently, terrestrial predators may be affected by a lack of appropriate prey leading to bottom-up and top-down effects in terrestrial food webs. This study indicates the importance of a responsible and elaborated use of Bti and additionally, highlights the need to include a temporal perspective in evaluations of stressors in aquatic-terrestrial meta-ecosystems.
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Affiliation(s)
- Sara Kolbenschlag
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany
| | - Verena Gerstle
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany
| | - Julian Eberhardt
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany
| | - Eric Bollinger
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany
| | - Ralf Schulz
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany; Eußerthal Ecosystem Research Station, University of Kaiserslautern-Landau (RPTU), Birkenthalstr. 13, D-76857 Eußerthal, Germany
| | - Carsten A Brühl
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany
| | - Mirco Bundschuh
- iES Landau, Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Fortstr. 7, D-76829 Landau, Germany; Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Lennart Hjelms väg 9, SWE-75007 Uppsala, Sweden.
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Cai L, Liu X, Tian Z, Michaud JP, Shen Z, Li Z, Zhang S, Liu X. Safety of Bacillus thuringiensis Cry1Ah and Vip3Aa toxins for the predatory stink bug Arma custos (Hemiptera: Pentatomidae). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158120. [PMID: 35987246 DOI: 10.1016/j.scitotenv.2022.158120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 08/05/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
The widespread adoption of Bt crops expressing insecticidal proteins derived from Bacillus thuringiensis has created a need to assess the potential effects of these toxins on non-target organisms, especially species such as Arma custos, a generalist predator that provides important biological control services in many field crops in Asia. Direct dietary exposure of A. custos to Cry1Ah and Vip3Aa proteins produced no adverse effects on life history traits, despite continuous exposure throughout development and early adult life to concentrations significantly higher than the Bt protein concentration likely encountered by A.custos in the field, even when feeding directly on Bt plants. Enzyme-linked immunosorbent assay confirmed the presence of Bt proteins in A. custos midguts, but quantitative real-time PCR analysis of 12 genes associated with detoxification, antioxidative responses, immune responses, and metabolism revealed no significant changes in expression in adult bugs. Indirect exposure to these toxins via consumption of intoxicated prey, larvae of Helicoverpa armigera (Hübner), likewise produced no negative impacts on survival, development, adult weight, or female fecundity in either the F0 (exposed) or F1 (unexposed) generation, but female fresh weight was reduced in the F0 generation by the Cry1Ah (50 μg/g) treatment. Finally, a competitive binding assay with labelled protein and a ligand blotting assay both demonstrated that the Cry1Ah protein could not bind to receptors on the midgut brush border membrane vesicles (BBMVs) of A. custos adults. Therefore, we conclude that Cry1Ah and Vip3Aa proteins are unlikely to have significant negative effects on A. custos populations if employed as plant-incorporated protectants in field crops.
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Affiliation(s)
- Limei Cai
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Xiaoming Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Zhiqiang Tian
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - J P Michaud
- Department of Entomology, Kansas State University, Agricultural Research Station-Hays, Hays, KS 67601, USA
| | - Zhongjian Shen
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Zhen Li
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Songdou Zhang
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China
| | - Xiaoxia Liu
- Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, 100193 Beijing, China.
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Guan ZJ, Zhou QJ, Shi H, Tang ZX, Liu B, Wei W. Effect of Transgenic Cotton Expressing Bt Cry1Ac or Cry1Ab/Ac Toxins on Lacewing Larvae Mediated by Herbivorous Insect Pests. PLANTS (BASEL, SWITZERLAND) 2022; 11:2755. [PMID: 36297779 PMCID: PMC9607298 DOI: 10.3390/plants11202755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Revised: 10/06/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
A simple food chain (plant, insect pests, and predatory arthropods) in an agro-ecosystem was set up here as a model system to elucidate the potential effect of transgenic Bacillus thuringiensis (Bt) cotton on non-target organisms. The system included transgenic/non-transgenic cotton, neonate larvae of three herbivorous insects (Spodoptera exigua, Helicoverpa armigera, and S. litura), and predatory lacewing larvae (Chrysopa spp.), which represent the first, second, and third trophic levels, respectively. The results showed that transgenic treatments and different densities of prey had significant effects on both body-weight gain of neonate herbivorous larvae and the number of prey captured by lacewing larvae, respectively. It was found that Bt toxin could persist at the third trophic level in lacewing larvae. The diet mixture bioassay showed that body-weight gain of lacewing larvae was significantly affected by various treatments, especially at lower concentrations of plant-expressed Bt toxin in the diet mixture, which caused significant decreases in body-weight gain. In contrast, synthetic Bt toxin at higher concentrations in the diet did not show this effect. Thus, we inferred that Bt toxin indirectly affected the growth of the lacewings and the lacewings may not be susceptible to Bt toxin or are able to metabolize it.
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Affiliation(s)
- Zheng-Jun Guan
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- Department of Life Sciences, Yuncheng University, Yuncheng 044000, China
| | - Qiu-Ju Zhou
- Institutes of Science and Development, Chinese Academy of Sciences, Beijing 100190, China
| | - Hong Shi
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Zhi-Xi Tang
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Biao Liu
- Nanjing Institute of Environmental Sciences, Ministry of Ecology and Environment of P. R. China, Nanjing 210042, China
| | - Wei Wei
- State Key Laboratory of Vegetation and Climate Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
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Poulin B, Lefebvre G, Hilaire S, Després L. Long-term persistence and recycling of Bacillus thuringiensis israelensis spores in wetlands sprayed for mosquito control. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 243:114004. [PMID: 36007317 DOI: 10.1016/j.ecoenv.2022.114004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/18/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Bacillus thuringiensis subsp. israelensis (Bti) is the main larvicide used to control mosquitoes worldwide. Although there is accumulating evidence of Bti having environmental effects on non-target fauna, relatively few field studies have documented the fate of Bti spores in the environment. Spore density was quantified over a 6-yr period (2012-2017) in Mediterranean marshes sprayed with Vectobac 12AS (32 ITU/ha) since 2006 to reduce the nuisance caused by Aedes caspius. Bti spores were naturally found in all habitat types. Spore density expressed as colony-forming units per gram of soil (CFU g-1) increased significantly at treated sites by a factor of 22 to 500 times relative to control sites, with mean values of 7730 CFU g-1 in halophilous scrubs, 38,000 in reed beds, 49,000 in bulrush beds and 50 000 in rush beds. Spore density varied little in the first months after the spraying season (April-October), but increased sharply in spring, just before the annual launch of mosquito control. Considering that Bti is an insect pathogen that cannot proliferate without a suitable insect host, this unexpected recrudescence in spring could be related to the warming of water that triggers activity and development of benthic organisms such as chironomids, which may contribute to Bti proliferation by ingesting accumulated spores at the surface of sediments. While spore density tends to decrease over time, presumably during the summer period as a result of increased UV exposure, three to four years were necessary for spore density to return to normal levels after mosquito-control interruption. This study is important because it demonstrates that environmental effects of mosquito-control using Bti can far exceed the short period of Bti efficacy against lentic mosquitoes. Considering that Bti is a microbial agent, these long-term effects should be addressed at multiple levels of ecosystem organization from a one-health perspective.
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Affiliation(s)
- Brigitte Poulin
- Tour duValat Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, 13200 Arles, France.
| | - Gaëtan Lefebvre
- Tour duValat Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, 13200 Arles, France.
| | - Samuel Hilaire
- Tour duValat Research Institute for the Conservation of Mediterranean Wetlands, Le Sambuc, 13200 Arles, France.
| | - Laurence Després
- Univ. Grenoble-Alpes, Univ. Savoie Mont Blanc, CNRS, Laboratoire d'Ecologie Alpine, 38000 Grenoble, France.
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Robles-Fort A, Pescador-Dionisio S, García-Robles I, Sentandreu V, Martínez-Ramírez AC, Real MD, Rausell C. Unveiling gene expression regulation of the Bacillus thuringiensis Cry3Aa toxin receptor ADAM10 by the potato dietary miR171c in Colorado potato beetle. PEST MANAGEMENT SCIENCE 2022; 78:3760-3768. [PMID: 34846789 DOI: 10.1002/ps.6743] [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: 10/15/2021] [Revised: 11/17/2021] [Accepted: 11/30/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND The Colorado potato beetle (CPB) is a worldwide devastating pest of potato plants and other Solanaceae characterized by its remarkable ability to evolve resistance to insecticides. Bacillus thuringiensis (Bt) Cry3Aa toxin represents an environmentally safe alternative for CPB control but larvae susceptibility to this toxin has been reported to vary depending on the host plant on which larvae feed. To gain more insight into how nutrition mediates Bt tolerance through effects on gene expression, here we explored the post-transcriptional regulation by microRNAs (miRNAs) of the CPB-ADAM10 gene encoding the Cry3Aa toxin functional receptor ADAM10. RESULTS The lower CPB-ADAM10 gene expression in CPB larvae fed on potato plants cv. Vivaldi than those fed on potato cv. Monalisa or tomato plants was inversely related to Cry3Aa toxicity. By high-throughput sequencing we identified seven CPB miRNAs and one potato miRNA predicted to base pair with the CPB-ADAM10 messenger RNA. No differential expression of the endogenous lde-miR1175-5p was found in larvae feeding on any of the two potato plant varieties. However, statistically significant increased amounts of potato stu-miR171c-5p were detected in CPB larvae fed on potato cv. Vivaldi compared to larvae fed on potato cv. Monalisa. CONCLUSION Our results support a role for dietary miRNAs in Bt toxicity by regulating the CPB-ADAM10 gene encoding the Cry3Aa toxin receptor ADAM10 in CPB larvae and opening up the possibility of exploiting plant natural variation in miRNAs to provide more sustainable potato crop protection against CPB. © 2021 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
- Aida Robles-Fort
- Department of Genetics, University of Valencia, Burjassot, Spain
| | | | | | - Vicente Sentandreu
- Servicios Centrales de Soporte a la Investigación Experimental (SCSIE), University of Valencia, Burjassot, Spain
| | - Amparo C Martínez-Ramírez
- Servicios Centrales de Soporte a la Investigación Experimental (SCSIE), University of Valencia, Burjassot, Spain
| | - M Dolores Real
- Department of Genetics, University of Valencia, Burjassot, Spain
| | - Carolina Rausell
- Department of Genetics, University of Valencia, Burjassot, Spain
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Mastore M, Caramella S, Quadroni S, Brivio MF. Drosophila suzukii Susceptibility to the Oral Administration of Bacillus thuringiensis, Xenorhabdus nematophila and Its Secondary Metabolites. INSECTS 2021; 12:insects12070635. [PMID: 34357295 PMCID: PMC8305655 DOI: 10.3390/insects12070635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/07/2021] [Accepted: 07/11/2021] [Indexed: 11/26/2022]
Abstract
Simple Summary In recent decades, climate change and the international fruit trade have favored the movement of allochthonous species such as harmful insects into new geographic areas. The settlement of phytophagous insects and vectors in new areas, where potential predators are often lacking, has increased the use of chemical insecticides for their control. The intensive use of these substances represents a serious problem for ecosystems and human health; a possible alternative to chemical control is biological control, i.e., the use of biological insecticides that are compatible with the environment. The aim of our work was to further improve biological control methods for the management of the dipteran Spotted Wing Drosophila, an insect recently introduced in America and Europe, which can damage thin-skinned fruit crops. The methodologies applied are based on the combined use of different entomopathogens, i.e., bacteria, fungi, nematodes, etc., harmful for insects, with the purpose of increasing their effectiveness. The results obtained show that the combined use of two entomopathogenic bacteria increases both the lethality and rapidity of action. From an application viewpoint, studies like this are essential to identify new methods and bioinsecticides and, once transferred to the field, can be crucial to eliminate or, at least, reduce the use of chemicals. Abstract Drosophila suzukii, Spotted Wing Drosophila (SWD), is a serious economic issue for thin-skinned fruit farmers. The invasion of this dipteran is mainly counteracted by chemical control methods; however, it would be desirable to replace them with biological control. All assays were performed with Bacillus thuringiensis (Bt), Xenorhabdus nematophila (Xn), and Xn secretions, administered orally in single or combination, then larval lethality was assessed at different times. Gut damage caused by Bt and the influence on Xn into the hemocoelic cavity was also evaluated. In addition, the hemolymph cell population was analyzed after treatments. The data obtained show that the combined use of Bt plus Xn secretions on larvae, compared to single administration of bacteria, significantly improved the efficacy and reduced the time of treatments. The results confirm the destructive action of Bt on the gut of SWD larvae, and that Bt-induced alteration promotes the passage of Xn to the hemocoel cavity. Furthermore, hemocytes decrease after bioinsecticides treatments. Our study demonstrates that combining bioinsecticides can improve the efficacy of biocontrol and such combinations should be tested in greenhouse and in field in the near future.
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Affiliation(s)
- Maristella Mastore
- Laboratory of Comparative Immunology and Parasitology, Department of Theoretical and Applied Sciences, University of Insubria, 21100 Varese, Italy; (M.M.); (S.C.)
| | - Sara Caramella
- Laboratory of Comparative Immunology and Parasitology, Department of Theoretical and Applied Sciences, University of Insubria, 21100 Varese, Italy; (M.M.); (S.C.)
| | - Silvia Quadroni
- Laboratory of Ecology, Department of Theoretical and Applied Sciences, University of Insubria, 21100 Varese, Italy;
| | - Maurizio Francesco Brivio
- Laboratory of Comparative Immunology and Parasitology, Department of Theoretical and Applied Sciences, University of Insubria, 21100 Varese, Italy; (M.M.); (S.C.)
- Correspondence: ; Tel.: +39-0332-421404
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