scholarly journals ABC transporter functions as a pacemaker for sequestration of plant glucosides in leaf beetles

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Anja S Strauss ◽  
Sven Peters ◽  
Wilhelm Boland ◽  
Antje Burse

Plant-herbivore interactions dominate the planet’s terrestrial ecology. When it comes to host–plant specialization, insects are among the most versatile evolutionary innovators, able to disarm multiple chemical plant defenses. Sequestration is a widespread strategy to detoxify noxious metabolites, frequently for the insect’s own benefit against predation. In this study, we describe the broad-spectrum ATP-binding cassette transporter CpMRP of the poplar leaf beetle, Chrysomela populi as the first candidate involved in the sequestration of phytochemicals in insects. CpMRP acts in the defensive glands of the larvae as a pacemaker for the irreversible shuttling of pre-selected metabolites from the hemolymph into defensive secretions. Silencing CpMRP in vivo creates a defenseless phenotype, indicating its role in the secretion process is crucial. In the defensive glands of related leaf beetle species, we identified sequences similar to CpMRP and assume therefore that exocrine gland-based defensive strategies, evolved by these insects to repel their enemies, rely on ABC transporters as a key element.

2012 ◽  
Vol 279 (1745) ◽  
pp. 4126-4134 ◽  
Author(s):  
René Roberto Bodemann ◽  
Peter Rahfeld ◽  
Magdalena Stock ◽  
Maritta Kunert ◽  
Natalie Wielsch ◽  
...  

Allomones are widely used by insects to impede predation. Frequently these chemical stimuli are released from specialized glands. The larvae of Chrysomelina leaf beetles produce allomones in gland reservoirs into which the required precursors and also the enzymes are secreted from attached gland cells. Hence, the reservoirs can be considered as closed bio-reactors for producing defensive secretions. We used RNA interference (RNAi) to analyse in vivo functions of proteins in biosynthetic pathways occurring in insect secretions. After a salicyl alcohol oxidase was silenced in juveniles of the poplar leaf beetles, Chrysomela populi , the precursor salicyl alcohol increased to 98 per cent, while salicyl aldehyde was reduced to 2 per cent within 5 days. By analogy, we have silenced a novel protein annotated as a member of the juvenile hormone-binding protein superfamily in the juvenile defensive glands of the related mustard leaf beetle, Phaedon cochleariae . The protein is associated with the cyclization of 8-oxogeranial to iridoids (methylcyclopentanoid monoterpenes) in the larval exudates made clear by the accumulation of the acylic precursor 5 days after RNAi triggering. A similar cyclization reaction produces the secologanin part of indole alkaloids in plants.


2008 ◽  
Vol 82 (5) ◽  
pp. 1035-1037 ◽  
Author(s):  
Carlos García-Robledo ◽  
Charles L. Staines

It is suggested that rolled-leaf hispine beetles (Hispinae, Coleoptera) and plants from the order Zingiberales maintained a highly specialized plant-herbivore interaction for >60 My. The evidence supporting this old and conservative interaction are herbivory marks found on leaves of the genus Zingiberopsis (Zingiberaceae) from the latest Cretaceous and early Eocene. This fossil herbivory was described as the ichnotaxon Cephaloleichnites strongii (Hispinae, Coleoptera), based on the assumption that this type of herbivory can be solely attributed to extant rolled-leaf beetles. This ichnotaxon has been a key element in several analyses on the origin, radiation and diversification of tropical insect herbivores. In this paper we report feeding patterns equivalent to those described in Zingiberopsis fossils but produced by larvae of Pyralidae and Choreutidae (Lepidoptera) and Anopsilus weevils (Curculionidae, Coleoptera) in four families of extant Zingiberales. We discuss the implications of C. strongii not being a rolled leaf beetle and how this may affect the current knowledge of the co-diversification of rolled-leaf beetles and their host plants from the order Zingiberales.


2017 ◽  
Vol 106 (1) ◽  
pp. 347-356 ◽  
Author(s):  
Wei Huang ◽  
Elias Zwimpfer ◽  
Maxime R. Hervé ◽  
Zoe Bont ◽  
Matthias Erb

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Masataka Nishiga ◽  
Takahiro Horie ◽  
Yasuhide Kuwabara ◽  
Osamu Baba ◽  
Tetsushi Nakao ◽  
...  

Background: A highly conserved microRNA, miR-33 is considered as a potential therapeutic target for atherosclerosis, because recent reports, including ours, indicated miR-33 has atherogenic effects by reducing HDL-C. However, the functions of miR-33 in heart failure remain to be elucidated. Methods and results: To clarify the functions of miR-33 involved in cardiac hypertrophy and fibrosis in vivo, we investigated the responses to pressure overload by transverse aortic constriction (TAC) in miR-33 deficient (KO) mice. When subjected to TAC, miR-33 expression level was significantly up-regulated in wild-type (WT) left ventricles, whereas miR-33 KO hearts displayed no less hypertrophic responses than WT hearts. However, interestingly, histological and gene expression analyses showed ameliorated cardiac fibrosis in miR-33 KO hearts compared to WT hearts. Furthermore, we generated cardiac fibroblast specific miR-33 deficient mice, which also showed ameliorated cardiac fibrosis when they were subjected to TAC. We also found that cardiac fibroblasts were mainly responsible for miR-33 expression in the heart, because its expression was about 4-folds higher in isolated primary cardiac fibroblasts than cardiomyocytes. Deficiency of miR-33 impaired cell proliferation in primary fibroblasts, which was considered due to altered lipid raft cholesterol content by up-regulated ATP-binding cassette transporter A1/G1. Conclusion: Deficiency of miR-33 impaired fibroblast proliferation in vitro, and ameliorated cardiac fibrosis induced by pressure overload in vivo.


2006 ◽  
Vol 37 (4) ◽  
pp. 467-479 ◽  
Author(s):  
Gregor Kölsch ◽  
Bo Vest Pedersen ◽  
Olof Biström

AbstractThe genus Macroplea Samouelle, 1819 is a group of highly specialized aquatic leaf beetles occurring in the Palaearctic. Since the members of this genus are morphologically very similar, we addressed the question of species identification and delimitation by analysing the second half of the mitochondrial gene coding for the cytochrome oxidase I (COI) subunit. Species limits are inferred from the multimodal frequency distribution of genetic distances between specimens: low genetic distances within a species are clearly set apart from distances between species. The species status of the hitherto controversial species M. japana (Jacoby, 1885) is confirmed. The pattern of nucleotide and amino acid substitutions is discussed in the light of functional domains of the COI molecule. Although the data are preliminary, the results provide new data on the distribution of the species. Together with the phylogenetic analysis they allow for a discussion of the phylogeography of the genus.


2021 ◽  
Author(s):  
Meret Huber ◽  
Thomas Roder ◽  
Sandra Irmisch ◽  
Alexander Riedel ◽  
Saskia Gablenz ◽  
...  

Gut enzymes can metabolize plant defense metabolites and thereby affect the growth and fitness of insect herbivores. Whether these enzymes also influence herbivore behavior and feeding preference is largely unknown. We studied the metabolization of taraxinic acid β-D-glucopyranosyl ester (TA-G), a sesquiterpene lactone of the common dandelion (Taraxacum officinale) that deters its major root herbivore, the common cockchafer larva (Melolontha melolontha). We demonstrate that TA-G is rapidly deglycosylated and conjugated to glutathione in the insect gut. A broad-spectrum M. melolontha β-glucosidase, Mm_bGlc17, is sufficient and necessary for TA-G deglycosylation. Using plants and insect RNA interference, we show that Mm_bGlc17 reduces TA-G toxicity. Furthermore, Mm_bGlc17 is required for the preference of M. melolontha larvae for TA-G deficient plants. Thus, herbivore metabolism modulates both the toxicity and deterrence of a plant defense metabolite. Our work illustrates the multifacteted roles of insect digestive enzymes as mediators of plant-herbivore interactions.


2018 ◽  
Author(s):  
Kam-Cheng Yeong ◽  
Haruo Takizawa ◽  
Thor-Seng Liew

Sabah, northern Borneo is one of the world’s most well-recognized biodiversity hotspots famous for the incredible diversity of its flora and fauna. Plenty of studies of leaf beetle fauna from this region have been conducted over the past 30 years. Yet, our knowledge of the leaf beetle fauna from island habitats remains scarce despite Sabah having the highest number of islands in Malaysia (ca. 500 islands). In this study, we collected leaf beetle fauna from 13 islands off the west coast of Sabah between January 2016 and March 2017. All specimens were identified to species level. Species names were assigned when the specimens fitted the description of species in the literature and morpho-species were assigned when the species names could not be determined. In addition, DNA barcodes – mitochondarial COI gene – of the species were sequenced. A total of 68 species from 31 genera and 5 subfamilies were collected with 12 species name being determined. From the data it was established that Pulau Gaya has the highest species richness (42 species), followed by Pulau Tiga (22 species) and Pulau Sapangar (18 species). Furthermore, a total of 64 Barcode Index Numbers consisting of 101 DNA barcodes were obtained from 60 leaf beetle species. The mean intraspecific and interspecific distances were determined as 0.77 % and 16.11 %, respectively. In addition, DNA barcoding also reveals phenotypic variation in leaf beetle species, particularly in the case of the subfamily Galerucinae. This study provides baseline knowledge and information about the DNA barcodes of leaf beetle species on Sabah’s island habitats for use in future studies.


2019 ◽  
Vol 1 (2) ◽  
pp. 47-52
Author(s):  
Surenshy Bulu ◽  
Novi Ivonne Bullu ◽  
Anggraeni Dian Naomi Rupidara

Entomopathogen is one of the biological agents that infects the insects and can damage the body's metabolic system of insects. This objective of the study were to determine the entomopathogenic activity of S. marcescens on mortality of coconut leaf beetles larvae (B. longissima), and the time needed to reach LT50. The study used an experimental method with 6 treatments of varying S.marcescens volumes, consisting of A (distilled water as a control), B (5 ml), C (7.5 ml), D (10 ml), E (12.5 ml), and F (15 ml) with 4 replications. The data were analyzed using ANOVA and Probit LT50 test. The results showed that the volume of S.marcescens had an effect on mortality of coconut leaf beetle B. longissimi larvae. The best mortality rate at treatment E is 78% with the value of LT50 in treatment F is 42.15 hours. S.marcescens has entomopathogenic activity in coconut leaf beetles (B. longissima) Gestro larvae.


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