scholarly journals Precise RNAi-mediated silencing of metabolically active proteins in the defence secretions of juvenile leaf beetles

2012 ◽  
Vol 279 (1745) ◽  
pp. 4126-4134 ◽  
Author(s):  
René Roberto Bodemann ◽  
Peter Rahfeld ◽  
Magdalena Stock ◽  
Maritta Kunert ◽  
Natalie Wielsch ◽  
...  
Keyword(s):  
Alcohol Oxidase ◽  
Leaf Beetle ◽  
Leaf Beetles ◽  
Juvenile Hormone Binding Protein ◽  
Defensive Glands ◽  
Hormone Binding Protein ◽  
Chemical Stimuli ◽  
Poplar Leaf ◽  
Novel Protein

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.

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
Keyword(s):  
Leaf Beetle ◽  
Leaf Beetles ◽  
Host Plant Specialization ◽  
Defensive Strategies ◽  
Atp Binding Cassette Transporter ◽  
Defensive Glands ◽  
Herbivore Interactions ◽  
Plant Herbivore ◽  
Multiple Chemical

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.

Species delimitation in the leaf beetle genus Macroplea (Coleoptera, Chrysomelidae) based on mitochondrial DNA, and phylogeographic considerations

2006 ◽  
Vol 37 (4) ◽  
pp. 467-479 ◽  
Author(s):  
Gregor Kölsch ◽  
Bo Vest Pedersen ◽  
Olof Biström
Keyword(s):  
Phylogenetic Analysis ◽  
Mitochondrial Dna ◽  
Species Delimitation ◽  
Mitochondrial Gene ◽  
Leaf Beetle ◽  
Genetic Distances ◽  
Amino Acid Substitutions ◽  
Species Status ◽  
Leaf Beetles ◽  
Gene Coding

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.

The juvenile hormone binding protein of silkworm haemolymph: gene and functional analysis

2001 ◽  
Vol 10 (2) ◽  
pp. 147-154 ◽  
Author(s):  
A. M. W. Vermunt ◽  
M. Kamimura ◽  
M. Hirai ◽  
M. Kiuchi ◽  
T. Shiotsuki
Keyword(s):  
Functional Analysis ◽  
Juvenile Hormone ◽  
Binding Protein ◽  
Hormone Binding ◽  
Juvenile Hormone Binding Protein ◽  
Hormone Binding Protein

scholarly journals Investigating leaf beetles (Coleoptera, Chrysomelidae) on the west coast islands of Sabah via checklist-taking and DNA barcoding

2018 ◽  
Author(s):  
Kam-Cheng Yeong ◽  
Haruo Takizawa ◽  
Thor-Seng Liew
Keyword(s):  
Dna Barcoding ◽  
West Coast ◽  
Leaf Beetle ◽  
Coi Gene ◽  
Beetle Species ◽  
Dna Barcodes ◽  
The West ◽  
Leaf Beetles ◽  
Baseline Knowledge ◽  
Island Habitats

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.

scholarly journals IDENTIFIKASI MORFOLOGI BAKTERI ASAM LAKTAT PADA NIRA SEGAR LONTAR (Borassus flabellifer Linn)

2019 ◽  
Vol 1 (2) ◽  
pp. 47-52
Author(s):  
Surenshy Bulu ◽  
Novi Ivonne Bullu ◽  
Anggraeni Dian Naomi Rupidara
Keyword(s):  
Mortality Rate ◽  
Experimental Method ◽  
Leaf Beetle ◽  
Biological Agents ◽  
Distilled Water ◽  
Metabolic System ◽  
Leaf Beetles

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.

scholarly journals Host Specificity of the Parasitic Wasp Anaphes flavipes (Hymenoptera: Mymaridae) and a New Defence in Its Hosts (Coleoptera: Chrysomelidae: Oulema spp.)

Insects ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 175
Author(s):  
Alena Samková ◽  
Jiří Hadrava ◽  
Jiří Skuhrovec ◽  
Petr Janšta
Keyword(s):  
Biological Control ◽  
Czech Republic ◽  
Host Specificity ◽  
Parasitic Wasp ◽  
Leaf Beetle ◽  
Host Defence ◽  
Pest Species ◽  
New Host ◽  
Leaf Beetles ◽  
Study Laboratory

The parasitic wasp Anaphes flavipes (Förster, 1841) (Hymenoptera: Mymaridae) is an important egg parasitoid of cereal leaf beetles. Some species of cereal leaf beetle co-occur in the same localities, but the host specificity of the wasp to these crop pests has not yet been examined in detail. A lack of knowledge of host specificity can have a negative effect on the use of this wasps in biological control programs addressed to specific pest species or genus. In this study, laboratory experiments were conducted to assess the host specificity of A. flavipes for three species of cereal leaf beetles (Oulema duftschmidi Redtenbacher, 1874, Oulema gallaeciana Heyden, 1879 and Oulema melanopus Linnaeus, 1758) in central Europe. For the first time, a new host defence against egg parasitoids occurring in O. gallaeciana from localities in the Czech Republic, a strong dark sticky layer on the egg surface, was found and described. The host specificity of A. flavipes was studied in the locality with the presence of this defence on O. gallaeciana eggs (the dark sticky layer) (Czech Republic) and in a control locality (Germany), where no such host defence was observed. Contrary to the idea that a host defence mechanism can change the host specificity of parasitoids, the wasps from these two localities did not display any differences in that. Respectively, even though it has been observed that eggs with sticky dark layer can prevent parasitization, the overall rate of parasitization of the three species of cereal beetles has not been affected. However, in our view, new host defence can influence the effects of biological control, as eggs of all Oulema spp. in the locality are protected against parasitization from the wasps stuck on the sticky layer of the host eggs of O. gallaeciana.

scholarly journals ABCB transporters in a leaf beetle respond to sequestered plant toxins

2020 ◽  
Vol 287 (1934) ◽  
pp. 20201311
Author(s):  
Paulina Kowalski ◽  
Michael Baum ◽  
Marcel Körten ◽  
Alexander Donath ◽  
Susanne Dobler
Keyword(s):  
Host Plants ◽  
Leaf Beetle ◽  
Protective Role ◽  
Specific Storage ◽  
Toxic Compounds ◽  
Chrysochus Auratus ◽  
Defensive Glands ◽  
The One ◽  
Uptake And Transport

Phytophagous insects can tolerate and detoxify toxic compounds present in their host plants and have evolved intricate adaptations to this end. Some insects even sequester the toxins for their defence. This necessitates specific mechanisms, especially carrier proteins that regulate uptake and transport to specific storage sites or protect sensitive tissues from noxious compounds. We identified three ATP-binding cassette subfamily B (ABCB) transporters from the transcriptome of the cardenolide-sequestering leaf beetle Chrysochus auratus and analysed their functional role in the sequestration process. These were heterologously expressed and tested for their ability to interact with various potential substrates: verapamil (standard ABCB substrate), the cardenolides digoxin (commonly used), cymarin (present in the species's host plant) and calotropin (present in the ancestral host plants). Verapamil stimulated all three ABCBs and each was activated by at least one cardenolide, however, they differed as to which they were activated by. While the expression of the most versatile transporter fits with a protective role in the blood–brain barrier, the one specific for cymarin shows an extreme abundance in the elytra, coinciding with the location of the defensive glands. Our data thus suggest a key role of ABCBs in the transport network needed for cardenolide sequestration.

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