Search results for "Exigua"
showing 10 items of 49 documents
Influence of Diet, Sex, and Viral Infections on the Gut Microbiota Composition of Spodoptera exigua Caterpillars
2020
The gut microbiota plays essential roles in processes related with metabolism, physiology, and immunity in all organisms, including insects. In the present work, we performed a broad analysis of the Spodoptera exigua gut microbiota, a major agricultural pest. We analyzed the influence of multiple parameters such as diet, geographic location, sex, or viral infections on S. exigua caterpillar gut microbiota composition. Our study revealed a high variability in bacterial composition among individuals, and a major influence of environmental bacteria (including those acquired through diet) on the gut microbiota composition, supporting previous studies that claim resident microbiota are lacking i…
Iflavirus increases its infectivity and physical stability in association with baculovirus
2016
Virus transmission and the prevalence of infection depend on multiple factors, including the interaction with other viral pathogens infecting the same host. In this study, active replication of an iflavirus, Spodoptera exigua iflavirus 1 (order Picornavirales) was observed in the offspring of insects that survived following inoculation with a pathogenic baculovirus, Spodoptera exigua multiple nucleopolyhedrovirus. Tracking the origin of the iflavirus suggested the association of this virus with the occlusion bodies of the baculovirus. Here we investigated the effect of this association on the stability and infectivity of both viruses. A reduction in baculovirus pathogenicity, without affect…
A novel baculovirus-derived promoter with high activity in the baculovirus expression system
2016
The baculovirus expression vector system (BEVS) has been widely used to produce a large number of recombinant proteins, and is becoming one of the most powerful, robust, and cost-effective systems for the production of eukaryotic proteins. Nevertheless, as in any other protein expression system, it is important to improve the production capabilities of this vector. The orf46 viral gene was identified among the most highly abundant sequences in the transcriptome of Spodoptera exigua larvae infected with its native baculovirus, the S. exigua multiple nucleopolyhedrovirus (SeMNPV). Different sequences upstream of the orf46 gene were cloned, and their promoter activities were tested by the expr…
High Bacterial Agglutination Activity in a Single-CRD C-Type Lectin from Spodoptera exigua (Lepidoptera: Noctuidae)
2017
Lectins are carbohydrate-interacting proteins that play a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensors for capturing and identifying bacterial species. In this work, three C-type lectins from the Lepidoptera Spodoptera exigua were produced as recombinant proteins and their bacterial agglutination properties were characterized. The lowest protein concentration producing bacterial agglutination against a panel of different Gram+ an…
Occurrence of a common binding site in Mamestra brassicae, Phthorimaea operculella, and Spodoptera exigua for the insecticidal crystal proteins CryIA…
1997
Specific binding to midgut membrane proteins is required for the toxicity of insecticidal crystal proteins (ICP) from Bacillus thuringiensis. A direct relationship between toxicity and binding has been proposed. It has been hypothesized that sharing of a single receptor by more than one ICP could lead to the occurrence of multiple resistance in the event of an alteration in the common receptor. Binding of CryIA(a), CryIA(b) and CryIA(c), three structurally related ICPs, has been studied in Phthorimaea operculella, Mamestra brassicae and, Spodoptera exigua using brush border membrane vesicles (BBMV) from the midgut tissue. Using iodinated CryIA(b), the three insects showed similar results: o…
Common receptor for Bacillus thuringiensis toxins Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera, Helicoverpa zea and Spodoptera exigua
2005
ABSTRACT Binding studies using 125 I-Cry1Ac and biotinylated Cry1Fa toxins indicate the occurrence of a common receptor for Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera , Helicoverpa zea , and Spodoptera exigua . Our results, along with previous binding data and the observed cases of cross-resistance, suggest that this pattern seems to be widespread among lepidopteran species.
Host-range expansion of Spodoptera exigua multiple nucleopolyhedrovirus to Agrotis segetum larvae when the midgut is bypassed.
2010
Given the high similarity in genome content and organization between Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) and Agrotis segetum nucleopolyhedrovirus (AgseNPV), as well as the high percentages of similarity found between their 30 core genes, the specificity of these NPVs was analysed for the respective insect hosts, S. exigua and A. segetum. The LD(50) for AgseNPV in second-instar A. segetum larvae was 83 occlusion bodies per larva and the LT(50) was 8.1 days. AgseNPV was orally infectious for S. exigua, but the LD(50) was 10 000-fold higher than for SeMNPV. SeMNPV was not infectious for A. segetum larvae when administered orally, but an infection was established by injecti…
Euphorbia Nurae P. Fraga & Rosselló (Euphorbiaceae), a New Species from Minorca (Balearic Islands)
2011
Abstract FRAGA-ARGUIMBAU, P. & J. A. ROSSELLO (2011). Euphorbia nurae P. Fraga & Rossello (Euphorbiaceae), a new species from Minorca (Balearic Islands). Candollea 66: 181–190. In English, English and French abstracts. Euphorbia nurae P. Fraga & Rossello (Euphorbiaceae sect. Cymatospermum (Prokh.) Prokh.) is described as a new species from coastal sites of Minorca (Balearic Islands). Morphological features suggest that Euphorbia exigua L., Euphorbia dracunculoides Lam. and Euphorbia sulcata Loisel. are the most closely related taxa, but the new species can be easily discriminated by several morphological characters.
Specific binding of radiolabeled Cry1Fa insecticidal protein from Bacillus thuringiensis to midgut sites in lepidopteran species
2012
ABSTRACT Cry1Fa insecticidal protein was successfully radiolabeled with 125 I-Na. Specific binding to brush border membrane vesicles was shown for the lepidopteran species Ostrinia nubilalis , Spodoptera frugiperda , Spodoptera exigua , Helicoverpa armigera , Heliothis virescens , and Plutella xylostella . Homologous competition assays were performed to obtain equilibrium binding parameters ( K d [dissociation constant] and R t [concentration of binding sites]) for these six insect species.
Isolation and toxicity of Bacillus thuringiensis from potato-growing areas in Bolivia
2004
Bacillus thuringiensis was isolated from 116 samples collected in high altitude potato-growing areas in Bolivia. In these regions, main potato pests are the potato tuberworm Phthorimaea operculella, and the Andean weevils Premnotrypes latithorax and Rhigopsidius tucumanus. B. thuringiensis was found in 60% of the samples. The main percentage of samples with B. thuringiensis was found in larvae of R. tucumanus (78%). Bioassays were performed with 112 isolates. None resulted toxic to either larvae or adults of the two Andean weevils. However, 18 isolates from this study showed more toxicity against the beet armyworm Spodoptera exigua than the standard strain var. kurstaki isolated from DELFIN…