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Hu H, Yin X, Pang S, Jiang Y, Weng Q, Hu Q, Wang J. Mechanism of destruxin a inhibits juvenile hormone binding protein transporting juvenile hormone to affect insect growth. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 197:105654. [PMID: 38072529 DOI: 10.1016/j.pestbp.2023.105654] [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: 07/25/2023] [Revised: 09/22/2023] [Accepted: 10/17/2023] [Indexed: 12/18/2023]
Abstract
Destruxin A, a non-ribosomal peptide toxin produced by Metarhizium, exhibits potent insecticidal activity by targeting various tissues, organs, and cells of insects. Our previous research has revealed that DA possesses the ability to bind to multiple proteins. In this study, we aimed to identify the most sensitive binding proteins of DA and investigate the physiological processes in which DA regulated. Through RNAi technology, we screened 22 binding proteins of DA in silkworm hemolymph. Among them, the juvenile hormone binding protein (JHBP), a hormone transport protein crucial for growth and development regulation, exhibited the highest sensitivity to DA. Subsequent experiments demonstrated that DA could inhibit the body weight gain of silkworm larvae, accelerate the pupation occurrence, and modulate the content of free juvenile hormone (JH) in the hemolymph. We also observed that DA could induce conformational changes in both the JHBP and the JHBP-JH binding complex. Notably, at low dosage, DA influenced the binding of JHBP to JH, while at high dosage, it irreversibly affected the binding of JHBP to JH. Molecular docking and point-mutant experiments suggested that DA might affect the N-arm of JHBP, which is responsible for JH binding. Additionally, we discovered that JHBP is widely distributed in various tissues of the silkworm, including the epidermis, gut, fat body, Malpighian tubule, gonad, muscle, trachea, and hemocyte. This study provides novel insights into the insecticidal mechanism of DA and enhances our understanding of the pathogenic process of Metarhizium.
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Affiliation(s)
- Hongwang Hu
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Xuyu Yin
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Suyun Pang
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Yali Jiang
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Qunfang Weng
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Qiongbo Hu
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China.
| | - Jingjing Wang
- College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; College of Horticulture, South China Agricultural University, Guangzhou 510642, China.
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Wang J, Weng Q, Zhang K, Hu Q. Binding proteins of destruxin A from Metarhizium against insect cell. BMC Microbiol 2023; 23:96. [PMID: 37016280 PMCID: PMC10071776 DOI: 10.1186/s12866-023-02843-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/30/2023] [Indexed: 04/06/2023] Open
Abstract
Destruxin A (DA) is a cyclo-hexadepsipeptidic insecticidal mycotoxin isolated from the entomopathogenic fungi, Metarhizium spp. However, its mode of action is unknown. In this study, we isolated 149 candidate DA-binding proteins by drug affinity response target stability, and determined the interactions of 80 canditates with DA in vitro by surface plasmon resonance. The affinity coefficients (KD) ranged from 24 to 469 μM. Binding proteins were functionally diverse and included cytoskeletal components and cell motility, protein transcription and translation pathways, ubiquitin dependent protein metabolic processes, nucleus pore entry and exit, and endoplasmic reticulum vesicle transport and etc. Electron microscopy revealed that DA damaged the cytoskeleton and multiple organelles, disrupted cell adhesion and motility, and led to cell death. DA appeared to have a multi-targeted approach to cellular structures and multiple life processes, leading to cell death. The results of this study could provide molecular evidence for the analysis of the insecticidal toxicology of DA and further improve the study of the pathogenic insect mechanism of Metarhizium.
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Affiliation(s)
- Jingjing Wang
- National Key Laboratory of Green Pesticide; Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
- College of Horticulture, South China Agricultural University, Guangzhou, 510642, China
| | - Qunfang Weng
- National Key Laboratory of Green Pesticide; Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Ke Zhang
- National Key Laboratory of Green Pesticide; Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China
| | - Qiongbo Hu
- National Key Laboratory of Green Pesticide; Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, College of Plant Protection, South China Agricultural University, Guangzhou, 510642, China.
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Drosophila melanogaster as an emerging model host for entomopathogenic fungi. FUNGAL BIOL REV 2022. [DOI: 10.1016/j.fbr.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Han P, Gong Q, Fan J, Abbas M, Chen D, Zhang J. Destruxin A inhibits scavenger receptor B mediated melanization in Aphis citricola. PEST MANAGEMENT SCIENCE 2022; 78:1915-1924. [PMID: 35080798 DOI: 10.1002/ps.6809] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Destruxin A (DA) is a mycotoxin secreted by entomogenous fungi, such as Metarhizium anisopliae, which has broad-spectrum insecticidal activity. Insect innate immunity provides resistance against the invasion of entomopathogenic fungi. Previous studies have shown that DA could inhibit the immune response, however, the suppressive mechanism of DA on prophenoloxidase system is still unknown. RESULTS Based on the transcriptome of Aphis citricola, we screened the scavenger receptor class B(AcSR-B)and identified that it significantly responds to DA. Spatio-temporal expression analysis showed that AcSR-B is highly expressed in adult stage and is mainly distributed in the abdominal region. We further revealed that both M. anisopliae and Escherichia coli could suppress the expression of AcSR-B at 24 h, and that the expressed recombinant protein rAcSR-B possessed agglutination activity to M. anisopliae and E. coli. DA could suppress the protein expression of AcSR-B. In addition, RNA interference of AcSR-B caused death of A. citricola in a dose-dependent manner, and RNA interference of AcSR-B increased mortality in A. citricola under the same lethal concentration of DA. The inhibiting effect of AcSR-B silencing was similar with the DA treatment upon phenol oxidase (PO) activity of A. citricola hemolymph. DA could not decrease PO activity further after AcSR-B silencing. CONCLUSION Destruxin A inhibits melanization by suppressing AcSR-B in A. citricola. Our findings are helpful in understanding the underlying molecular mechanism of the DA suppressing immune system, and uncover a potential molecular target for double-stranded RNA (dsRNA) insecticides.
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Affiliation(s)
- Pengfei Han
- Institute of Applied Biology and College of Life Science, Shanxi University, Taiyuan, China
- Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China
| | - Qitian Gong
- Institute of Applied Biology and College of Life Science, Shanxi University, Taiyuan, China
- Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China
| | - Jiqiao Fan
- Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China
- College of Plant Protection, Shanxi Agricultural University, Taiyuan, China
| | - Mureed Abbas
- Institute of Applied Biology and College of Life Science, Shanxi University, Taiyuan, China
- Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China
| | - Duo Chen
- Institute of Applied Biology and College of Life Science, Shanxi University, Taiyuan, China
- Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China
| | - Jianzhen Zhang
- Institute of Applied Biology and College of Life Science, Shanxi University, Taiyuan, China
- Shanxi Key Laboratory of Integrated Pest Management in Agriculture, Taiyuan, China
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Kryukov VY, Rotskaya U, Yaroslavtseva O, Polenogova O, Kryukova N, Akhanaev Y, Krivopalov A, Alikina T, Vorontsova YL, Slepneva I, Kabilov M, Glupov VV. Fungus Metarhizium robertsii and neurotoxic insecticide affect gut immunity and microbiota in Colorado potato beetles. Sci Rep 2021; 11:1299. [PMID: 33446848 PMCID: PMC7809261 DOI: 10.1038/s41598-020-80565-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 12/14/2020] [Indexed: 12/13/2022] Open
Abstract
Fungal infections and toxicoses caused by insecticides may alter microbial communities and immune responses in the insect gut. We investigated the effects of Metarhizium robertsii fungus and avermectins on the midgut physiology of Colorado potato beetle larvae. We analyzed changes in the bacterial community, immunity- and stress-related gene expression, reactive oxygen species (ROS) production, and detoxification enzyme activity in response to topical infection with the M. robertsii fungus, oral administration of avermectins, and a combination of the two treatments. Avermectin treatment led to a reduction in microbiota diversity and an enhancement in the abundance of enterobacteria, and these changes were followed by the downregulation of Stat and Hsp90, upregulation of transcription factors for the Toll and IMD pathways and activation of detoxification enzymes. Fungal infection also led to a decrease in microbiota diversity, although the changes in community structure were not significant, except for the enhancement of Serratia. Fungal infection decreased the production of ROS but did not affect the gene expression of the immune pathways. In the combined treatment, fungal infection inhibited the activation of detoxification enzymes and prevented the downregulation of the JAK-STAT pathway caused by avermectins. The results of this study suggest that fungal infection modulates physiological responses to avermectins and that fungal infection may increase avermectin toxicosis by blocking detoxification enzymes in the gut.
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Affiliation(s)
- Vadim Yu Kryukov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia. .,Tomsk State University, Tomsk, 634050, Russia.
| | - Ulyana Rotskaya
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Olga Yaroslavtseva
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Olga Polenogova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Natalia Kryukova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Yuriy Akhanaev
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Anton Krivopalov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Tatyana Alikina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Yana L Vorontsova
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
| | - Irina Slepneva
- Voevodsky Institute of Chemical Kinetics and Combustion, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Marsel Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630090, Russia
| | - Viktor V Glupov
- Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences, Novosibirsk, 630091, Russia
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Effects of Destruxin A on Silkworm's Immunophilins. Toxins (Basel) 2019; 11:toxins11060349. [PMID: 31216655 PMCID: PMC6628623 DOI: 10.3390/toxins11060349] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/09/2019] [Accepted: 06/13/2019] [Indexed: 01/02/2023] Open
Abstract
Destruxin A (DA), a major secondary metabolite of Metarhizium anisopliae, has anti-immunity to insects. However, the detailed mechanism and its interactions with target proteins are elusive. Previously, three immunophilins, peptidyl–prolyl cis–trans isomerase (BmPPI), FK506 binding-protein 45 (BmFKBP45) and BmFKBP59 homologue, were isolated from the silkworm, Bombyx mori Bm12 cell line following treatment with DA, which suggested that these proteins were possible DA-binding proteins. To validate the interaction between DA and the three immunophilins, we performed bio-layer interferometry (BLI) assay, and the results showed that DA has interaction with BmPPI, whose affinity constant value is 1.98 × 10−3 M and which has no affinity with FKBP45 and FKBP59 homologue in vitro. Furthermore, we investigated the affinity between DA and human PPI protein (HsPPIA) and the affinity constant (KD) value is 2.22 × 10−3 M. Additionally, we compared the effects of silkworm and human PPI proteins produced by DA and immunosuppressants, cyclosporine A (CsA), and tacrolimus (FK506), by employing I2H (insect two-hybrid) in the SF-9 cell line. The results indicated that in silkworm, the effects created by DA and CsA were stronger than FK506. Furthermore, the effects created by DA in silkworm were stronger than those in humans. This study will offer new thinking to elucidate the molecular mechanism of DA in the immunity system of insects.
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Zhang H, Hu W, Xiao M, Ou S, Hu Q. Destruxin A Induces and Binds HSPs in Bombyx mori Bm12 Cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:9849-9853. [PMID: 29048160 DOI: 10.1021/acs.jafc.7b03734] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Destruxin A (DA) is a cyclodepsipeptidic mycotoxin isolated from the entomopathogenic fungus, Metarhizium anisopliae. It has insecticidal activity against host insect's innate immunity system, but the molecular mechanism is not yet elucidated. In our previous experiment, four HSPs (heat shock proteins, BmHSP70-3, BmHSP75, BmHSP83, and BmHSCP) were characterized from the specific protein electrophoretic bands of Bombyx mori Bm12 cell line treated with DA in the test of drug affinity responsive target stability (DARTS), which implied that these HSPs might be kinds of DA-affinity proteins, or DA induces them up-regulated expression. Therefore, in current research, the interactions of DA and HSPs were explored through analysis of bio-layer interferometry (BLI) employing FortBio OcteteQK. The expression levels of HSPs genes were surveyed by quantitative real-time polymerase chain reaction (qPCR). The results indicated that DA had no interactions with BmHSP70-3, BmHSP75, and BmHSP83, but had affinity to BmHSCP with a KD value of 88.1 μM, in BLI analysis. However, the expression levels of all HSPs genes were significantly up-regulated after the Bm12 cells were treated by DA. In conclusion, DA can induce the four HSPs expression in Bm12 cells, but DA only binds to BmHSCP. Our research provides new insights on understanding of the action mechanisms of destruxins.
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Affiliation(s)
- Huanhuan Zhang
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University , Guangzhou 510642, China
| | - Weina Hu
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University , Guangzhou 510642, China
| | - Miaomiao Xiao
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University , Guangzhou 510642, China
| | - Shiyi Ou
- Department of Food Science and Engineering, Jinan University , Guangzhou 510632, China
| | - Qiongbo Hu
- Key Laboratory of Bio-Pesticide Innovation and Application of Guangdong Province, College of Agriculture, South China Agricultural University , Guangzhou 510642, China
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Macheleidt J, Mattern DJ, Fischer J, Netzker T, Weber J, Schroeckh V, Valiante V, Brakhage AA. Regulation and Role of Fungal Secondary Metabolites. Annu Rev Genet 2016; 50:371-392. [DOI: 10.1146/annurev-genet-120215-035203] [Citation(s) in RCA: 219] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Juliane Macheleidt
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
| | - Derek J. Mattern
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
- Institute for Microbiology, Friedrich Schiller University Jena, 07737 Jena, Germany
| | - Juliane Fischer
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
- Institute for Microbiology, Friedrich Schiller University Jena, 07737 Jena, Germany
| | - Tina Netzker
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
- Institute for Microbiology, Friedrich Schiller University Jena, 07737 Jena, Germany
| | - Jakob Weber
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
- Institute for Microbiology, Friedrich Schiller University Jena, 07737 Jena, Germany
| | - Volker Schroeckh
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
| | - Vito Valiante
- Research Group Biobricks of Microbial Natural Product Syntheses, Leibniz Institute for Natural Product Research and Infection Biology (HKI), 07745 Jena, Germany;
| | - Axel A. Brakhage
- Department of Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology, Hans Knöll Institute (HKI), 07745 Jena, Germany; , , , , , ,
- Institute for Microbiology, Friedrich Schiller University Jena, 07737 Jena, Germany
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Shanbhag SR, Vazhappilly AT, Sane A, D'Silva NM, Tripathi S. Electrolyte transport pathways induced in the midgut epithelium of Drosophila melanogaster larvae by commensal gut microbiota and pathogens. J Physiol 2016; 595:523-539. [PMID: 27373966 DOI: 10.1113/jp272617] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/20/2016] [Indexed: 02/01/2023] Open
Abstract
KEY POINTS The digestive tract of larval and adult Drosophila is an excellent analogue of the mammalian gut. Enterocytes of the posterior midgut are separated by septa, with no paracellular path, and therefore perform both immune and transport functions. Using microperfusion electrophysiology, we show that larvae emerging from the embryo into sterile medium have symmetrical apical and basal membrane conductances while larvae emerging into non-sterile medium have apical membranes fivefold more conductive than basal membranes. The channels inserted into the apical membranes could originate in microbiata or host and mediate recognition of microbes. Entomopathogenic cyclic peptide toxins deplete intracellular ions reversibly, forming transient ion channels that do not conduct water, unlike an ionophore like nystatin that depletes ions irreversibly. We show the feasibility of studying the interaction of a single microbial species, or tractable combinatorials of microbial species, with only enterocytes in the primary epithelial barrier. ABSTRACT Microbiota colonizing exposed epithelial surfaces are vital for sustenance of metazoan life, but communication between microbiota, epithelial cells and the host immune system is only beginning to be understood. We address this issue in the posterior midgut epithelium of Drosophila larvae where nutrient transport and immune functions are exclusively transcellular. We showed that larvae emerging into a sterile post-embryonic environment have symmetrical apical and basal membranes. In contrast, larvae emerging into non-sterile media, the source of microbiota, have markedly asymmetrical membranes, with apical membrane conductance more than fivefold higher than the basal membrane. As an example of pathogen action, we showed that the entomopathogenic fungal toxin destruxin A (Dx) depleted intracellular ions. Reversibility of action of Dx was verified by bilayer reconstitution in forming transient non-specific channels that conduct ions but not water. Dx was also less effective from the apical side as compared to the basal side of the epithelium. We also showed that intercellular septa are not conductive in non-sterile cells, even though most cells are isopotential. Luminal microbiota therefore impart asymmetry to the epithelium, by activation of apical membrane conductance, enhancing inter-enterocyte communication, separated by insulating septa, via the gut lumen. These results also open the possibility of studying the basis of bidirectional molecular conversation specifically between enterocytes and microbiota that enables discrimination between commensals and pathogens, establishment of the former, and elimination of the latter.
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Affiliation(s)
- Shubha R Shanbhag
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India
| | | | - Abhay Sane
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India
| | - Natalie M D'Silva
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India
| | - Subrata Tripathi
- Tata Institute of Fundamental Research, Colaba, Mumbai, 400 005, India.,Institute of Physics, Sachivalaya Marg, Bhubaneswar, 751 005, India
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Browne A, O'Donnell MJ. Segment-specific Ca(2+) transport by isolated Malpighian tubules of Drosophila melanogaster: A comparison of larval and adult stages. JOURNAL OF INSECT PHYSIOLOGY 2016; 87:1-11. [PMID: 26802560 DOI: 10.1016/j.jinsphys.2016.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 01/08/2016] [Accepted: 01/19/2016] [Indexed: 06/05/2023]
Abstract
Haemolymph calcium homeostasis in insects is achieved through the regulation of calcium excretion by Malpighian tubules in two ways: (1) sequestration of calcium within biomineralized granules and (2) secretion of calcium in soluble form within the primary urine. Using the scanning ion-selective electrode technique (SIET), basolateral Ca(2+) transport was measured at the distal, transitional, main and proximal tubular segments of anterior tubules isolated from both 3rd instar larvae and adults of the fruit fly Drosophila melanogaster. Basolateral Ca(2+) transport exceeded transepithelial secretion by 800-fold and 11-fold in anterior tubules of larvae and adults, respectively. The magnitude of Ca(2+) fluxes across the distal tubule of larvae and adults were larger than fluxes across the downstream segments by 10 and 40 times, respectively, indicating a dominant role for the distal segment in whole animal Ca(2+) regulation. Basolateral Ca(2+) transport across distal tubules of Drosophila varied throughout the life cycle; Ca(2+) was released by distal tubules of larvae, taken up by distal tubules of young adults and was released once again by tubules of adults ⩾ 168 h post-eclosion. In adults and larvae, SIET measurements revealed sites of both Ca(2+) uptake and Ca(2+) release across the basolateral surface of the distal segment of the same tubule, indicating that Ca(2+) transport is bidirectional. Ca(2+) uptake across the distal segment of tubules of young adults and Ca(2+) release across the distal segment of tubules of older adults was also suggestive of reversible Ca(2+) storage. Our results suggest that the distal tubules of D. melanogaster are dynamic calcium stores which allow efficient haemolymph calcium regulation through active Ca(2+) sequestration during periods of high dietary calcium intake and passive Ca(2+) release during periods of calcium deficiency.
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Affiliation(s)
- Austin Browne
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada.
| | - Michael J O'Donnell
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada.
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11
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Ruiz-Sanchez E, O'Donnell MJ. The insect excretory system as a target for novel pest control strategies. CURRENT OPINION IN INSECT SCIENCE 2015; 11:14-20. [PMID: 28285757 DOI: 10.1016/j.cois.2015.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 06/06/2023]
Abstract
The insect excretory system plays essential roles in osmoregulation, ionoregulation and toxin elimination. Understanding the mechanisms of fluid and ion transport by the epithelial cells of the excretory system provides a foundation for development of novel pest management strategies. In the present review, we focus on two such strategies: first, impairment of osmoregulation by manipulation of diuretic or antidiuretic signaling pathways and second, interference with toxin elimination by inhibition of toxin transport systems.
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Affiliation(s)
- Esau Ruiz-Sanchez
- Instituto Tecnologico de Conkal, Km. 16.3, Ex-Carretera Merida-Motul, Conkal , Yucatan C.P. 97345, Mexico
| | - Michael J O'Donnell
- Department of Biology, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada.
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12
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Lozano-Tovar MD, Garrido-Jurado I, Lafont F, Quesada-Moraga E. Insecticidal Activity of a Destruxin-Containing Extract of Metarhizium brunneum Against Ceratitis capitata (Diptera: Tephritidae). JOURNAL OF ECONOMIC ENTOMOLOGY 2015; 108:462-472. [PMID: 26470157 DOI: 10.1093/jee/tov041] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/21/2015] [Indexed: 06/05/2023]
Abstract
Tephritid fruit flies are major pests that limit fruit production around the world; they cause important damages, increasing directly and indirectly annual costs, and their management is predominately based on the use of chemical insecticides. This research investigated the insecticidal activity of the crude extract obtained of Metarhizium brunneum Petch EAMb 09/01-Su strain and its capacity to secrete secondary metabolites including destruxins (dtx). Dtx A and A2 had insecticidal activity against Ceratitis capitata (Wiedemann) when administered per os. The crude extract of seven Metarhizium and one Beauveria isolates were evaluated per os against medfly adults. The crude extracts of the isolate EAMb 09/01-Su resulted in mortality ranging between 95 and 100% at 48 h. The high-pressure liquid chromatography profile showed two active peaks (F5B and F6 subfractions) related with dtx A2 and dtx A, which caused 70 and 100% mortality on C. capitata at 48 h postfeeding, respectively. The LC50 was 104.92 ppm of dtx A, contained in the F6 subfraction, and the LT50 was 4.16 h at a concentration of 400 ppm of dtx A contained in the F6 subfraction. Moreover, the average survival time of adults exposed to this subfraction was 12.6 h with only 1 h of exposure. The insecticide metabolites of the F6 subfraction of the EAMb 09/01-Su isolate retained >90% of its insecticidal activity after exposure to 60°C for 2 h and 120°C for 20 min. These results highlight the potential of this strain as a source of new insecticidal compounds of natural origin for fruit fly control.
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Affiliation(s)
- M D Lozano-Tovar
- Laboratory of Agricultural Entomology, Department of Agricultural and Forestry Sciences, ETSIAM, University of Cordoba, Campus de Rabanales. Edificio C4 Celestino Mutis. 14071 Cordoba, Spain
| | - I Garrido-Jurado
- Laboratory of Agricultural Entomology, Department of Agricultural and Forestry Sciences, ETSIAM, University of Cordoba, Campus de Rabanales. Edificio C4 Celestino Mutis. 14071 Cordoba, Spain
| | - F Lafont
- Mass Spectrometry & Chromatography Lab-SCAI, University of Cordoba, Campus de Rabanales. Edificio Ramon y Cajal. 14071 Córdoba, Spain
| | - E Quesada-Moraga
- Laboratory of Agricultural Entomology, Department of Agricultural and Forestry Sciences, ETSIAM, University of Cordoba, Campus de Rabanales. Edificio C4 Celestino Mutis. 14071 Cordoba, Spain.
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Chen XR, Hu QB, Yu XQ, Ren SX. Effects of destruxins on free calcium and hydrogen ions in insect hemocytes. INSECT SCIENCE 2014; 21:31-38. [PMID: 23956215 DOI: 10.1111/1744-7917.12028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/13/2013] [Indexed: 06/02/2023]
Abstract
Destruxins, cyclohexadepsipeptidic mycotoxins isolated from the entomopathogenic fungus Metarhizium anisopliae, inhibit innate insect immunity. However, their mechanism of action remains unclear. In this study, the effects of destruxins on changes in free calcium and hydrogen ions in the hemocytes of Exolontha serrulata, Bombyx mori and the Spodoptera litura SL-1 cell line were detected using laser scanning confocal microscopy (LSCM). An instant Ca(2+) influx of hemocytes induced by destruxins A and B (DA and DB) was recorded. The DA/DB-dependent Ca(2+) influx was not influenced by the Ca(2+) channel inhibitors 2-aminoethoxydiphenyl borane (2-APB) and U73122. It also had an apparently different LSCM profile from that of the ionomycin-dependent Ca(2+) influx. However, the instant Ca(2+) influx was not seen in the SL-1 cells; on the contrary, a slow, moderate enhancement of intracellular Ca(2+) was observed. Meanwhile, an instant intracellular free H(+) decrease aroused by DA and DB was found. DB at 20 μmol/L and DA at 690 μmol/L significantly reduced intracellular free H(+) levels. Furthermore, the vacuolar H(+)-ATPase (V-ATPase) inhibitor bafilomycin A1 had obvious effects on the decreases of intracellular free H(+) in hemocytes. These results suggest that the mechanism of DA/DB-dependent Ca(2+) influx is perhaps not related to Ca(2+) channels and ionophores; rather, the intracellular free H(+) decrease might be due to V-ATPase inhibition.
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Affiliation(s)
- Xiu-Run Chen
- College of Natural Resource and Environment, South China Agricultural University, Guangzhou, China
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