1
|
de Jager N, Shukla V, Koprivova A, Lyčka M, Bilalli L, You Y, Zeier J, Kopriva S, Ristova D. Traits linked to natural variation of sulfur content in Arabidopsis thaliana. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:1036-1050. [PMID: 37831920 PMCID: PMC10837017 DOI: 10.1093/jxb/erad401] [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: 08/24/2023] [Accepted: 10/12/2023] [Indexed: 10/15/2023]
Abstract
Sulfur (S) is an essential mineral nutrient for plant growth and development; it is important for primary and specialized plant metabolites that are crucial for biotic and abiotic interactions. Foliar S content varies up to 6-fold under a controlled environment, suggesting an adaptive value under certain natural environmental conditions. However, a major quantitative regulator of S content in Arabidopsis thaliana has not been identified yet, pointing to the existence of either additional genetic factors controlling sulfate/S content or of many minor quantitative regulators. Here, we use overlapping information of two separate ionomics studies to select groups of accessions with low, mid, and high foliar S content. We quantify series of metabolites, including anions (sulfate, phosphate, and nitrate), thiols (cysteine and glutathione), and seven glucosinolates, gene expression of 20 genes, sulfate uptake, and three biotic traits. Our results suggest that S content is tightly connected with sulfate uptake, the concentration of sulfate and phosphate anions, and glucosinolate and glutathione synthesis. Additionally, our results indicate that the growth of pathogenic bacteria is enhanced in the A. thaliana accessions containing higher S in their leaves, suggesting a complex regulation between S homeostasis, primary and secondary metabolism, and biotic pressures.
Collapse
Affiliation(s)
- Nicholas de Jager
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, D-50674 Cologne, Germany
| | - Varsa Shukla
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, D-50674 Cologne, Germany
| | - Anna Koprivova
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, D-50674 Cologne, Germany
| | - Martin Lyčka
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University, 625 00 Brno, Czech Republic
- National Centre for Biomolecular Research, Faculty of Science, Masaryk University, 625 00 Brno, Czech Republic
| | - Lorina Bilalli
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, D-50674 Cologne, Germany
| | - Yanrong You
- Institute for Molecular Ecophysiology of Plants, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Jürgen Zeier
- Institute for Molecular Ecophysiology of Plants, Cluster of Excellence on Plant Sciences (CEPLAS), Heinrich Heine University, Universitätsstraße 1, D-40225 Düsseldorf, Germany
| | - Stanislav Kopriva
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, D-50674 Cologne, Germany
| | - Daniela Ristova
- Institute for Plant Sciences, Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, D-50674 Cologne, Germany
| |
Collapse
|
2
|
Chakraborty S, Schuster S. How Plant Toxins Cause Early Larval Mortality in Herbivorous Insects: An Explanation by Modeling the Net Energy Curve. Toxins (Basel) 2024; 16:72. [PMID: 38393150 PMCID: PMC10892588 DOI: 10.3390/toxins16020072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 01/09/2024] [Accepted: 01/18/2024] [Indexed: 02/25/2024] Open
Abstract
Plants store chemical defenses that act as toxins against herbivores, such as toxic isothiocyanates (ITCs) in Brassica plants, hydrolyzed from glucosinolate (GLS) precursors. The fitness of herbivorous larvae can be strongly affected by these toxins, causing immature death. We modeled this phenomenon using a set of ordinary differential equations and established a direct relationship between feeding, toxin exposure, and the net energy of a larva, where the fitness of an organism is proportional to its net energy according to optimal foraging theory. Optimal foraging theory is widely used in ecology to model the feeding and searching behavior of organisms. Although feeding provides energy gain, plant toxins and foraging cause energy loss for the larvae. Our equations explain that toxin exposure and foraging can sharply reduce larval net energy to zero at an instar. Since herbivory needs energy, the only choice left for a larva is to stop feeding at that time point. If that is significantly earlier than the end of the last instar stage, the larva dies without food. Thus, we show that plant toxins can cause immature death in larvae from the perspective of optimal foraging theory.
Collapse
Affiliation(s)
- Suman Chakraborty
- Department of Bioinformatics, Matthias Schleiden Institute, Friedrich Schiller University Jena, Ernst-Abbe-Pl. 2, 07743 Jena, Germany;
- International Max Planck Research School “Chemical Communication in Ecological Systems”, 07745 Jena, Germany
| | - Stefan Schuster
- Department of Bioinformatics, Matthias Schleiden Institute, Friedrich Schiller University Jena, Ernst-Abbe-Pl. 2, 07743 Jena, Germany;
| |
Collapse
|
3
|
Körnig J, Ortizo K, Sporer T, Yang ZL, Beran F. Different myrosinases activate sequestered glucosinolates in larvae and adults of the horseradish flea beetle. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 163:104040. [PMID: 37995833 DOI: 10.1016/j.ibmb.2023.104040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 11/09/2023] [Accepted: 11/13/2023] [Indexed: 11/25/2023]
Abstract
β-Glucosidases play an important role in the chemical defense of many insects by hydrolyzing and thereby activating glucosylated pro-toxins that are either synthesized de novo or sequestered from the insect's diet. The horseradish flea beetle, Phyllotreta armoraciae, sequesters pro-toxic glucosinolates from its brassicaceous host plants and possesses endogenous β-thioglucosidase enzymes, known as myrosinases, for glucosinolate activation. Here, we identify three myrosinase genes in P. armoraciae (PaMyr) with distinct expression patterns during beetle ontogeny. By using RNA interference, we demonstrate that PaMyr1 is responsible for myrosinase activity in adults, whereas PaMyr2 is responsible for myrosinase activity in larvae. Compared to PaMyr1 and PaMyr2, PaMyr3 was only weakly expressed in our laboratory population, but may contribute to myrosinase activity in larvae. Silencing of PaMyr2 resulted in lower larval survival in a predation experiment and also reduced the breakdown of sequestered glucosinolates in uninjured larvae. This suggests that PaMyr2 is involved in both activated defense and the endogenous turnover of sequestered glucosinolates in P. armoraciae larvae. In activity assays with recombinant enzymes, PaMyr1 and PaMyr2 preferred different glucosinolates as substrates, which was consistent with the enzyme activities in crude protein extracts from adults and larvae, respectively. These differences were unexpected because larvae and adults sequester the same glucosinolates. Possible reasons for different myrosinase activities in Phyllotreta larvae and adults are discussed.
Collapse
Affiliation(s)
- Johannes Körnig
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany; Department Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Kris Ortizo
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Theresa Sporer
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Zhi-Ling Yang
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany; Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China
| | - Franziska Beran
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany; Department Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany; Population Ecology Group, Friedrich-Schiller Universität Jena, Jena, Germany.
| |
Collapse
|
4
|
Dixit S, Widemann E, Bensoussan N, Salehipourshirazi G, Bruinsma K, Milojevic M, Shukla A, Romero LC, Zhurov V, Bernards MA, Chruszcz M, Grbić M, Grbić V. β-Cyanoalanine synthase protects mites against Arabidopsis defenses. PLANT PHYSIOLOGY 2022; 189:1961-1975. [PMID: 35348790 PMCID: PMC9342966 DOI: 10.1093/plphys/kiac147] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/07/2022] [Indexed: 05/06/2023]
Abstract
Glucosinolates are antiherbivory chemical defense compounds in Arabidopsis (Arabidopsis thaliana). Specialist herbivores that feed on brassicaceous plants have evolved various mechanisms aimed at preventing the formation of toxic isothiocyanates. In contrast, generalist herbivores typically detoxify isothiocyanates through glutathione conjugation upon exposure. Here, we examined the response of an extreme generalist herbivore, the two-spotted spider mite Tetranychus urticae (Koch), to indole glucosinolates. Tetranychus urticae is a composite generalist whose individual populations have a restricted host range but have an ability to rapidly adapt to initially unfavorable plant hosts. Through comparative transcriptomic analysis of mite populations that have differential susceptibilities to Arabidopsis defenses, we identified β-cyanoalanine synthase of T. urticae (TuCAS), which encodes an enzyme with dual cysteine and β-cyanoalanine synthase activities. We combined Arabidopsis genetics, chemical complementation and mite reverse genetics to show that TuCAS is required for mite adaptation to Arabidopsis through its β-cyanoalanine synthase activity. Consistent with the β-cyanoalanine synthase role in detoxification of hydrogen cyanide (HCN), we discovered that upon mite herbivory, Arabidopsis plants release HCN. We further demonstrated that indole glucosinolates are sufficient for cyanide formation. Overall, our study uncovered Arabidopsis defenses that rely on indole glucosinolate-dependent cyanide for protection against mite herbivory. In response, Arabidopsis-adapted mites utilize the β-cyanoalanine synthase activity of TuCAS to counter cyanide toxicity, highlighting the mite's ability to activate resistant traits that enable this extreme polyphagous herbivore to exploit cyanogenic host plants.
Collapse
Affiliation(s)
| | | | - Nicolas Bensoussan
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | | | - Kristie Bruinsma
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Maja Milojevic
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Akanchha Shukla
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Luis C Romero
- Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, E-41092 Seville, Spain
| | - Vladimir Zhurov
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Mark A Bernards
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | - Maksymilian Chruszcz
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina, 29208, USA
| | - Miodrag Grbić
- Department of Biology, The University of Western Ontario, London, Ontario, Canada N6A 5B7
| | | |
Collapse
|
5
|
Unique metabolism of different glucosinolates in larvae and adults of a leaf beetle specialised on Brassicaceae. Sci Rep 2022; 12:10905. [PMID: 35764778 PMCID: PMC9240079 DOI: 10.1038/s41598-022-14636-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 06/09/2022] [Indexed: 01/12/2023] Open
Abstract
Brassicaceae plants contain glucosinolates, which are hydrolysed by myrosinases to toxic products such as isothiocyanates and nitriles, acting as defences. Herbivores have evolved various detoxification strategies, which are reviewed here. Larvae of Phaedon cochleariae (Coleoptera: Chrysomelidae) metabolise hydrolysis products of benzenic glucosinolates by conjugation with aspartic acid. In this study, we investigated whether P. cochleariae uses the same metabolic pathway for structurally different glucosinolates, whether the metabolism differs between adults and larvae and which hydrolysis products are formed as intermediates. Feeding experiments were performed with leaves of watercress (Nasturtium officinale, Brassicaceae) and pea (Pisum sativum, non-Brassicaceae), to which glucosinolates with structurally different side chains (benzenic, indole or aliphatic) or their hydrolysis products were applied. Samples were analysed by UHPLC-QTOF-MS/MS or TD–GC–MS. The same aspartic acid conjugates as previously identified in larvae were also detected as major metabolites of benzenic glucosinolates in adults. Indol-3-ylmethyl glucosinolate was mainly metabolised to N-(1H-indol-3-ylcarbonyl) glutamic acid in adults and larvae, while the metabolism of 2-propenyl glucosinolate remains unclear. The metabolism may thus proceed primarily via isothiocyanates rather than via nitriles, while the hydrolysis occurs independently of plant myrosinases. A detoxification by conjugation with these amino acids is not yet known from other Brassicaceae-feeders.
Collapse
|
6
|
Zhao C, Zhu F, Sun Q, Zhou X. Editorial: Mechanisms and Strategies of Arthropod Adaptation to the Chemical Environment. Front Physiol 2022; 13:889757. [PMID: 35399276 PMCID: PMC8990235 DOI: 10.3389/fphys.2022.889757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 11/30/2022] Open
Affiliation(s)
- Chaoyang Zhao
- Center for Medical, Agricultural and Veterinary Entomology, United States Department of Agriculture, Agricultural Research Service, Gainesville, FL, United States
- *Correspondence: Chaoyang Zhao,
| | - Fang Zhu
- Department of Entomology, Pennsylvania State University, University Park, PA, United States
| | - Qian Sun
- Department of Entomology, Louisiana State University, Baton Rouge, LA, United States
| | - Xuguo Zhou
- Department of Entomology, University of Kentucky, Lexington, KY, United States
| |
Collapse
|
7
|
Yang ZL, Seitz F, Grabe V, Nietzsche S, Richter A, Reichelt M, Beutel R, Beran F. Rapid and Selective Absorption of Plant Defense Compounds From the Gut of a Sequestering Insect. Front Physiol 2022; 13:846732. [PMID: 35309070 PMCID: PMC8928188 DOI: 10.3389/fphys.2022.846732] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 01/31/2022] [Indexed: 01/28/2023] Open
Abstract
Many herbivorous insects exploit defense compounds produced by their host plants for protection against predators. Ingested plant defense compounds are absorbed via the gut epithelium and stored in the body, a physiological process that is currently not well understood. Here, we investigated the absorption of plant defense compounds from the gut in the horseradish flea beetle, Phyllotreta armoraciae, a specialist herbivore known to selectively sequester glucosinolates from its brassicaceous host plants. Feeding experiments using a mixture of glucosinolates and other glucosides not found in the host plants showed a rapid and selective uptake of glucosinolates in adult beetles. In addition, we provide evidence that this uptake mainly takes place in the foregut, whereas the endodermal midgut is the normal region of absorption. Absorption via the foregut epithelium is surprising as the apical membrane is covered by a chitinous intima. However, we could show that this cuticular layer differs in its structure and overall thickness between P. armoraciae and a non-sequestering leaf beetle. In P. armoraciae, we observed a thinner cuticle with a less dense chitinous matrix, which might facilitate glucosinolate absorption. Our results show that a selective and rapid uptake of glucosinolates from the anterior region of the gut contributes to the selective sequestration of glucosinolates in P. armoraciae.
Collapse
Affiliation(s)
- Zhi-Ling Yang
- Research Group Sequestration and Detoxification in Insects, Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Fabian Seitz
- Research Group Sequestration and Detoxification in Insects, Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Veit Grabe
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Sandor Nietzsche
- Elektronenmikroskopisches Zentrum, Universitätsklinikum Jena, Jena, Germany
| | - Adrian Richter
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Rolf Beutel
- Institut für Zoologie und Evolutionsforschung, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Franziska Beran
- Research Group Sequestration and Detoxification in Insects, Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
- *Correspondence: Franziska Beran,
| |
Collapse
|
8
|
Beran F, Petschenka G. Sequestration of Plant Defense Compounds by Insects: From Mechanisms to Insect-Plant Coevolution. ANNUAL REVIEW OF ENTOMOLOGY 2022; 67:163-180. [PMID: 34995091 DOI: 10.1146/annurev-ento-062821-062319] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Plant defense compounds play a key role in the evolution of insect-plant associations by selecting for behavioral, morphological, and physiological insect adaptations. Sequestration, the ability of herbivorous insects to accumulate plant defense compounds to gain a fitness advantage, represents a complex syndrome of adaptations that has evolved in all major lineages of herbivorous insects and involves various classes of plant defense compounds. In this article, we review progress in understanding how insects selectively accumulate plant defense metabolites and how the evolution of specific resistance mechanisms to these defense compounds enables sequestration. These mechanistic considerations are further integrated into the concept of insect-plant coevolution. Comparative genome and transcriptome analyses, combined with approaches based on analytical chemistry that are centered in phylogenetic frameworks, will help to reveal adaptations underlying the sequestration syndrome, which is essential to understanding the influence of sequestration on insect-plant coevolution.
Collapse
Affiliation(s)
- Franziska Beran
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena 07745, Germany;
| | - Georg Petschenka
- Department of Applied Entomology, University of Hohenheim, Stuttgart 70599, Germany;
| |
Collapse
|
9
|
Cerritos-Garcia DG, Avery PB, Martini X, Candian V, Cano LM, Cave RD. In Vitro Effects of Leaf Extracts from Brassica rapa on the Growth of Two Entomopathogenic Fungi. J Fungi (Basel) 2021; 7:779. [PMID: 34575817 PMCID: PMC8468573 DOI: 10.3390/jof7090779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 09/10/2021] [Accepted: 09/15/2021] [Indexed: 11/16/2022] Open
Abstract
This study aimed to determine the inhibitive or stimulatory effects of leaf extracts from two Brassica rapa subspecies on the hyphal growth of two well-known entomopathogenic fungi, Cordyceps fumosorosea and Beauveria bassiana. Extract concentrations of 50, 25, and 10% w/v based on leaf fresh weight were prepared from turnip (B. rapa subspecies rapa) and bok choy (B. rapa subspecies chinensis) leaves. Each concentration was individually incorporated into potato dextrose agar plates for in vitro bioassays. The center of each plate was inoculated with 20 µL of a fungal suspension that was allowed 24 h to soak into the agar before sealing the plates and incubating them at 25 °C under a 14-h photophase. The fungal colony perimeter was marked 5 days after inoculation on two perpendicular lines drawn on the bottom of each plate. Radial colony growth was measured from 4 marks per plate 5, 10, and 15 days later. Radial growth rates for both fungi were 1.3-2.0 and 0.9-1.4 times faster with bok choy and turnip extracts, respectively, at the 25% and 50% concentrations compared to the no-extract control treatment. Therefore, bok choy and turnip leaf extracts can stimulate entomopathogenic fungus growth within 15 days. Biochemical compounds in the extracts include sesquiterpenes, α-copaene, β-selinene, γ-gurjunene, calamenene, cubenene, and α-calacorene.
Collapse
Affiliation(s)
- Daniel G. Cerritos-Garcia
- Indian River Research and Education Center, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945, USA; (D.G.C.-G.); (R.D.C.)
- Department of Agricultural Sciences and Production, Zamorano University, San Antonio de Oriente, Fco. Morazán, Honduras
| | - Pasco B. Avery
- Indian River Research and Education Center, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945, USA; (D.G.C.-G.); (R.D.C.)
| | - Xavier Martini
- North Florida Research and Education Center, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, Quincy, FL 32352, USA;
| | - Valentina Candian
- Indian River Research and Education Center, Department of Plant Pathology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945, USA; (V.C.); (L.M.C.)
- Department of Agricultural, Forest and Food Sciences (DISAFA), University of Torino, 2 Largo P. Braccini, 10095 Grugliasco, Italy
| | - Liliana M. Cano
- Indian River Research and Education Center, Department of Plant Pathology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945, USA; (V.C.); (L.M.C.)
| | - Ronald D. Cave
- Indian River Research and Education Center, Department of Entomology and Nematology, Institute of Food and Agricultural Sciences (IFAS), University of Florida, 2199 South Rock Road, Fort Pierce, FL 34945, USA; (D.G.C.-G.); (R.D.C.)
| |
Collapse
|
10
|
Sporer T, Körnig J, Wielsch N, Gebauer-Jung S, Reichelt M, Hupfer Y, Beran F. Hijacking the Mustard-Oil Bomb: How a Glucosinolate-Sequestering Flea Beetle Copes With Plant Myrosinases. FRONTIERS IN PLANT SCIENCE 2021; 12:645030. [PMID: 34093609 PMCID: PMC8173161 DOI: 10.3389/fpls.2021.645030] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/13/2021] [Indexed: 06/12/2023]
Abstract
Myrosinase enzymes play a key role in the chemical defense of plants of the order Brassicales. Upon herbivory, myrosinases hydrolyze the β-S-linked glucose moiety of glucosinolates, the characteristic secondary metabolites of brassicaceous plants, which leads to the formation of different toxic hydrolysis products. The specialist flea beetle, Phyllotreta armoraciae, is capable of accumulating high levels of glucosinolates in the body and can thus at least partially avoid plant myrosinase activity. In feeding experiments with the myrosinase-deficient Arabidopsis thaliana tgg1 × tgg2 (tgg) mutant and the corresponding Arabidopsis Col-0 wild type, we investigated the influence of plant myrosinase activity on the metabolic fate of ingested glucosinolates in adult P. armoraciae beetles. Arabidopsis myrosinases hydrolyzed a fraction of ingested glucosinolates and thereby reduced the glucosinolate sequestration rate by up to 50% in adult beetles. These results show that P. armoraciae cannot fully prevent glucosinolate hydrolysis; however, the exposure of adult beetles to glucosinolate hydrolysis products had no impact on the beetle's energy budget under our experimental conditions. To understand how P. armoraciae can partially prevent glucosinolate hydrolysis, we analyzed the short-term fate of ingested glucosinolates and found them to be rapidly absorbed from the gut. In addition, we determined the fate of ingested Arabidopsis myrosinase enzymes in P. armoraciae. Although we detected Arabidopsis myrosinase protein in the feces, we found only traces of myrosinase activity, suggesting that P. armoraciae can inactivate plant myrosinases in the gut. Based on our findings, we propose that the ability to tolerate plant myrosinase activity and a fast glucosinolate uptake mechanism represent key adaptations of P. armoraciae to their brassicaceous host plants.
Collapse
Affiliation(s)
- Theresa Sporer
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Johannes Körnig
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Natalie Wielsch
- Research Group Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Steffi Gebauer-Jung
- Department of Insect Symbiosis, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Michael Reichelt
- Department of Biochemistry, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Yvonne Hupfer
- Research Group Mass Spectrometry/Proteomics, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Franziska Beran
- Research Group Sequestration and Detoxification in Insects, Max Planck Institute for Chemical Ecology, Jena, Germany
| |
Collapse
|
11
|
Sugar transporters enable a leaf beetle to accumulate plant defense compounds. Nat Commun 2021; 12:2658. [PMID: 33976202 PMCID: PMC8113468 DOI: 10.1038/s41467-021-22982-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 04/06/2021] [Indexed: 02/03/2023] Open
Abstract
Many herbivorous insects selectively accumulate plant toxins for defense against predators; however, little is known about the transport processes that enable insects to absorb and store defense compounds in the body. Here, we investigate how a specialist herbivore, the horseradish flea beetle, accumulates glucosinolate defense compounds from Brassicaceae in the hemolymph. Using phylogenetic analyses of coleopteran major facilitator superfamily transporters, we identify a clade of glucosinolate-specific transporters (PaGTRs) belonging to the sugar porter family. PaGTRs are predominantly expressed in the excretory system, the Malpighian tubules. Silencing of PaGTRs leads to elevated glucosinolate excretion, significantly reducing the levels of sequestered glucosinolates in beetles. This suggests that PaGTRs reabsorb glucosinolates from the Malpighian tubule lumen to prevent their loss by excretion. Ramsay assays corroborated the selective retention of glucosinolates by Malpighian tubules of P. armoraciae in situ. Thus, the selective accumulation of plant defense compounds in herbivorous insects can depend on the ability to prevent excretion.
Collapse
|
12
|
Glucosinolate induces transcriptomic and metabolic reprogramming in Helicoverpa armigera. 3 Biotech 2021; 11:26. [PMID: 33442524 DOI: 10.1007/s13205-020-02596-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 12/15/2020] [Indexed: 12/19/2022] Open
Abstract
Glucosinolates protect plants from herbivory. Lepidopteran insects have developed resistance to glucosinolates which is well studied. However, the molecular effects of glucosinolate intake on insects are unexplored. To elucidate this, we performed transcriptomics and metabolomics of sinigrin-fed Helicoverpa armigera. Transcriptomics exhibits significant dysregulation of 2375 transcripts, of which 1575 are upregulated and 800 downregulated. Gene Ontology analysis of differentially expressed genes reveals that key hydrolases, oxidoreductases, and transferases are majorly affected. The negative impact of sinigrin is significant and localized in the endomembrane system and mitochondria. It also disturbs various biological processes such as regulation of protein metabolism and cytoskeletal organization. Furthermore, H. armigera putative myrosinase-like enzymes may catalyze the breakdown of sinigrin to allyl isothiocyanate (AITC). AITC targets the electron transport chain causing oxidative stress. KEGG pathway enrichment shows significant upregulation of oxidative phosphorylation, glutathione metabolism and amino acid metabolism. Activation of these pathways induces glutathione synthesis for sinigrin detoxification. Differential gene expression indicates upregulation of glutathione S-transferase and succinate dehydrogenase suggesting mitochondrial impact. Transcriptomics data correlated with metabolomics show changes in serine, methionine, ornithine, and other metabolite levels. It corroborates well with the transcript alterations supporting the increased glutathione production. Thus, our data suggest that sinigrin generates oxidative stress in H. armigera and insects alter their metabolic wiring to overcome sinigrin-mediated deleterious effects. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s13205-020-02596-5.
Collapse
|
13
|
Glucosinolate Biosynthesis and the Glucosinolate–Myrosinase System in Plant Defense. AGRONOMY-BASEL 2020. [DOI: 10.3390/agronomy10111786] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Insect pests represent a major global challenge to important agricultural crops. Insecticides are often applied to combat such pests, but their use has caused additional challenges such as environmental contamination and human health issues. Over millions of years, plants have evolved natural defense mechanisms to overcome insect pests and pathogens. One such mechanism is the production of natural repellents or specialized metabolites like glucosinolates. There are three types of glucosinolates produced in the order Brassicales: aliphatic, indole, and benzenic glucosinolates. Upon insect herbivory, a “mustard oil bomb” consisting of glucosinolates and their hydrolyzing enzymes (myrosinases) is triggered to release toxic degradation products that act as insect deterrents. This review aims to provide a comprehensive summary of glucosinolate biosynthesis, the “mustard oil bomb”, and how these metabolites function in plant defense against pathogens and insects. Understanding these defense mechanisms will not only allow us to harness the benefits of this group of natural metabolites for enhancing pest control in Brassicales crops but also to transfer the “mustard oil bomb” to non-glucosinolate producing crops to boost their defense and thereby reduce the use of chemical pesticides.
Collapse
|
14
|
Sporer T, Körnig J, Beran F. Ontogenetic differences in the chemical defence of flea beetles influence their predation risk. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13548] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Theresa Sporer
- Research Group Sequestration and Detoxification in Insects Max Planck Institute for Chemical Ecology Jena Germany
| | - Johannes Körnig
- Research Group Sequestration and Detoxification in Insects Max Planck Institute for Chemical Ecology Jena Germany
| | - Franziska Beran
- Research Group Sequestration and Detoxification in Insects Max Planck Institute for Chemical Ecology Jena Germany
| |
Collapse
|