scholarly journals Effect of Cry Toxins on Xylotrechus arvicola (Coleoptera: Cerambycidae) Larvae

Insects ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Álvaro Rodríguez-González ◽  
Alejandra J. Porteous-Álvarez ◽  
Marcos Guerra ◽  
Óscar González-López ◽  
Pedro A. Casquero ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Iberian Peninsula ◽  
Cry Proteins ◽  
Cry Toxins ◽  
Laboratory Conditions ◽  
Biological Development

The beetle Xylotrechus arvicola is a destructive pest in vineyards (Vitis vinifera) in the main wine-producing areas of the Iberian Peninsula. X. arvicola larvae bore into the grapevine wood-making galleries, thus damaging the plant both directly and indirectly; the latter through the proliferation of wood fungi, which can invade the inside of the plant, decreasing the quality and quantity of its production. The susceptibility of X. arvicola larvae to five coleopteran toxic Cry proteins (Cry1B, Cry1I, Cry3A, Cry7A, and Cry23/37) was evaluated under laboratory conditions in order to deepen the knowledge of the effect of these proteins on this insect throughout its biological development.

scholarly journals Use of Bacillus thuringiensis Toxins for Control of the Cotton Pest Earias insulana (Boisd.) (Lepidoptera: Noctuidae)

2006 ◽  
Vol 72 (1) ◽  
pp. 437-442 ◽  
Author(s):  
María A. Ibargutxi ◽  
Anna Estela ◽  
Juan Ferré ◽  
Primitivo Caballero
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Sites ◽  
Specific Binding ◽  
Significant Inhibition ◽  
The Other ◽  
Cross Resistance ◽  
Earias Insulana ◽  
Cry Proteins ◽  
Cry Toxins ◽  
Laboratory Colony

ABSTRACT Thirteen of the most common lepidopteran-specific Cry proteins of Bacillus thuringiensis have been tested for their efficacy against newly hatched larvae of two populations of the spiny bollworm, Earias insulana. At a concentration of 100 μg of toxin per milliliter of artificial diet, six Cry toxins (Cry1Ca, Cry1Ea, Cry1Fa, Cry1Ja, Cry2Aa, and Cry2Ab) were not toxic at all. Cry1Aa, Cry1Ja, and Cry2Aa did not cause mortality but caused significant inhibition of growth. The other Cry toxins (Cry1Ab, Cry1Ac, Cry1Ba, Cry1Da, Cry1Ia, and Cry9Ca) were toxic to E. insulana larvae. The 50% lethal concentration values of these toxins ranged from 0.39 to 21.13 μg/ml (for Cry9Ca and Cry1Ia, respectively) for an E. insulana laboratory colony originating from Egypt and from 0.20 to 4.25 μg/ml (for Cry9Ca and Cry1Da, respectively) for a laboratory colony originating from Spain. The relative potencies of the toxins in the population from Egypt were highest for Cry9Ca and Cry1Ab, and they were both significantly more toxic than Cry1Ac and Cry1Ba, followed by Cry1Da and finally Cry1Ia. In the population from Spain, Cry9Ca was the most toxic, followed in decreasing order by Cry1Ac and Cry1Ba, and the least toxic was Cry1Da. Binding experiments were performed to test whether the toxic Cry proteins shared binding sites in this insect. 125I-labeled Cry1Ac and Cry1Ab and biotinylated Cry1Ba, Cry1Ia, and Cry9Ca showed specific binding to the brush border membrane vesicles from E. insulana. Competition binding experiments among these toxins showed that only Cry1Ab and Cry1Ac competed for the same binding sites, indicating a high possibility that this insect may develop cross-resistance to Cry1Ab upon exposure to Cry1Ac transgenic cotton but not to the other toxins tested.

Vitis vinifera in the Iberian Peninsula: A review

2016 ◽  
Vol 151 (2) ◽  
pp. 245-257 ◽  
Author(s):  
M. J. Iriarte-Chiapusso ◽  
C.A. Ocete-Pérez ◽  
B. Hernández-Beloqui ◽  
R. Ocete-Rubio
Keyword(s):  
Vitis Vinifera ◽  
Iberian Peninsula

Grape varieties (Vitis vinifera L.) from the Balearic Islands: genetic characterization and relationship with Iberian Peninsula and Mediterranean Basin

2011 ◽  
Vol 59 (4) ◽  
pp. 589-605 ◽  
Author(s):  
Sonia García-Muñoz ◽  
Thierry Lacombe ◽  
M. Teresa de Andrés ◽  
Laura Gaforio ◽  
Gregorio Muñoz-Organero ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Iberian Peninsula ◽  
Mediterranean Basin ◽  
Genetic Characterization ◽  
Balearic Islands ◽  
Vitis Vinifera L ◽  
Grape Varieties

scholarly journals Influence of Rootstock Type on the Agronomic Characteristics of Two Grape (>Vitis vinifera L.) Cultivars Grown in the Northwestern Iberian Peninsula

2007 ◽  
Vol 10 (4) ◽  
pp. 473-477 ◽  
Author(s):  
José Luis Santiago ◽  
Pilar Gago ◽  
Susana Boso ◽  
Virginia Alonso-Villaverde ◽  
Carmen Martínez
Keyword(s):  
Vitis Vinifera ◽  
Iberian Peninsula ◽  
Vitis Vinifera L ◽  
Agronomic Characteristics ◽  
Northwestern Iberian Peninsula

scholarly journals Lack of Detrimental Effects of Bacillus thuringiensis Cry Toxins on the Insect Predator Chrysoperla carnea: a Toxicological, Histopathological, and Biochemical Analysis

2006 ◽  
Vol 72 (2) ◽  
pp. 1595-1603 ◽  
Author(s):  
Ana Rodrigo-Simón ◽  
Ruud A. de Maagd ◽  
Carlos Avilla ◽  
Petra L. Bakker ◽  
Jos Molthoff ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Cell Damage ◽  
Specific Binding ◽  
Real Life ◽  
Chrysoperla Carnea ◽  
Green Lacewing ◽  
Cry Proteins ◽  
Cry Toxins

ABSTRACT The effect of Cry proteins of Bacillus thuringiensis on the green lacewing (Chrysoperla carnea) was studied by using a holistic approach which consisted of independent, complementary experimental strategies. Tritrophic experiments were performed, in which lacewing larvae were fed Helicoverpa armigera larvae reared on Cry1Ac, Cry1Ab, or Cry2Ab toxins. In complementary experiments, a predetermined amount of purified Cry1Ac was directly fed to lacewing larvae. In both experiments no effects on prey utilization or fitness parameters were found. Since binding to the midgut is an indispensable step for toxicity of Cry proteins to known target insects, we hypothesized that specific binding of the Cry1A proteins should be found if the proteins were toxic to the green lacewing. In control experiments, Cry1Ac was detected bound to the midgut epithelium of intoxicated H. armigera larvae, and cell damage was observed. However, no binding or histopathological effects of the toxin were found in tissue sections of lacewing larvae. Similarly, Cry1Ab or Cry1Ac bound in a specific manner to brush border membrane vesicles from Spodoptera exigua but not to similar fractions from green lacewing larvae. The in vivo and in vitro binding results strongly suggest that the lacewing larval midgut lacks specific receptors for Cry1Ab or Cry1Ac. These results agree with those obtained in bioassays, and we concluded that the Cry toxins tested, even at concentrations higher than those expected in real-life situations, do not have a detrimental effect on the green lacewing when they are ingested either directly or through the prey.

scholarly journals Evaluating Cross-resistance Between Vip and Cry Toxins of Bacillus thuringiensis

2019 ◽  
Vol 113 (2) ◽  
pp. 553-561 ◽  
Author(s):  
Bruce E Tabashnik ◽  
Yves Carrière
Keyword(s):  
Bacillus Thuringiensis ◽  
Genetically Engineered ◽  
Cross Resistance ◽  
Published Data ◽  
Data Sets ◽  
Cry Proteins ◽  
Cry Toxins ◽  
Bt Crops ◽  
Resistant Strains ◽  
Bacterium Bacillus

Abstract Crops genetically engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) have revolutionized control of some major pests. Some recently introduced Bt crops make Vip3Aa, a vegetative insecticidal protein (Vip), which reportedly does not share binding sites or structural homology with the crystalline (Cry) proteins of Bt used widely in transgenic crops for more than two decades. Field-evolved resistance to Bt crops with practical consequences for pest control includes 21 cases that collectively reduce the efficacy of nine Cry proteins, but such practical resistance has not been reported yet for any Vip. Here, we review previously published data to evaluate cross-resistance between Vip and Cry toxins. We analyzed 31 cases based on 48 observations, with each case based on one to five observations assessing cross-resistance from pairwise comparisons between 21 resistant strains and 13 related susceptible strains of eight species of lepidopteran pests. Confirming results from previous analyses of smaller data sets, we found weak, statistically significant cross-resistance between Vip3 and Cry1 toxins, with a mean of 1.5-fold cross-resistance in 21 cases (range: 0.30–4.6-fold). Conversely, we did not detect significant positive cross-resistance between Vip3 toxins and Cry2Ab. Distinguishing between weak, significant cross-resistance, and no cross-resistance may be useful for better understanding mechanisms of resistance and effectively managing pest resistance to Bt crops.

scholarly journals Insect Hsp90 Chaperone Assists Bacillus thuringiensis Cry Toxicity by Enhancing Protoxin Binding to the Receptor and by Protecting Protoxin from Gut Protease Degradation

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Blanca I. García-Gómez ◽  
Sayra N. Cano ◽  
Erika E. Zagal ◽  
Edgar Dantán-Gonzalez ◽  
Alejandra Bravo ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Receptor Binding ◽  
Insecticidal Activity ◽  
Insect Pests ◽  
Biotechnological Applications ◽  
Cry Proteins ◽  
Cry Toxins ◽  
Content Type ◽  
Hsp90 Chaperone ◽  
Protease Degradation

ABSTRACT Bacillus thuringiensis Cry proteins are pore-forming insecticidal toxins with specificity against different crop pests and insect vectors of human diseases. Previous work suggested that the insect host Hsp90 chaperone could be involved in Cry toxin action. Here, we show that the interaction of Cry toxins with insect Hsp90 constitutes a positive loop to enhance the performance of these toxins. Plutella xylostella Hsp90 (PxHsp90) greatly enhanced Cry1Ab or Cry1Ac toxicity when fed together to P. xylostella larvae and also in the less susceptible Spodoptera frugiperda larvae. PxHsp90 bound Cry1Ab and Cry1Ac protoxins in an ATP- and chaperone activity-dependent interaction. The chaperone Hsp90 participates in the correct folding of proteins and may suppress mutations of some client proteins, and we show here that PxHsp90 recovered the toxicity of the Cry1AbG439D protoxin affected in receptor binding, in contrast to the Cry1AbR99E or Cry1AbE129K mutant, affected in oligomerization or membrane insertion, respectively, which showed a slight toxicity improvement. Specifically, PxHsp90 enhanced the binding of Cry1AbG439D protoxin to the cadherin receptor. Furthermore, PxHsp90 protected Cry1A protoxins from degradation by insect midgut proteases. Our data show that PxHsp90 assists Cry1A proteins by enhancing their binding to the receptor and by protecting Cry protoxin from gut protease degradation. Finally, we show that the insect cochaperone protein PxHsp70 also increases the toxicity of Cry1Ac in P. xylostella larvae, in contrast to a bacterial GroEL chaperone, which had a marginal effect, indicating that the use of insect chaperones along with Cry toxins could have important biotechnological applications for the improvement of Cry insecticidal activity, resulting in effective control of insect pests. IMPORTANCE Bacillus thuringiensis took advantage of important insect cellular proteins, such as chaperones, involved in maintaining protein homeostasis, to enhance its insecticidal activity. This constitutes a positive loop where the concentrations of Hsp90 and Hsp70 in the gut lumen are likely to increase as midgut cells burst due to Cry1A pore formation action. Hsp90 protects Cry1A protoxin from degradation and enhances receptor binding, resulting in increased toxicity. The effect of insect chaperones on Cry toxicity could have important biotechnological applications to enhance the toxicity of Cry proteins to insect pests, especially those that show low susceptibility to these toxins.

scholarly journals The Cytocidal Spectrum of Bacillus thuringiensis Toxins: From Insects to Human Cancer Cells

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 301 ◽  
Author(s):  
Gretel Mendoza-Almanza ◽  
Edgar L. Esparza-Ibarra ◽  
Jorge L. Ayala-Luján ◽  
Marisa Mercado-Reyes ◽  
Susana Godina-González ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Cell Membrane ◽  
Cancer Cells ◽  
Insecticidal Activity ◽  
Human Cancer ◽  
Membrane Receptors ◽  
Specific Cell ◽  
Cry Proteins ◽  
Cry Toxins ◽  
Human Cancer Cells

Bacillus thuringiensis (Bt) is a ubiquitous bacterium in soils, insect cadavers, phylloplane, water, and stored grain, that produces several proteins, each one toxic to different biological targets such as insects, nematodes, mites, protozoa, and mammalian cells. Most Bt toxins identify their particular target through the recognition of specific cell membrane receptors. Cry proteins are the best-known toxins from Bt and a great amount of research has been published. Cry are cytotoxic to insect larvae that affect important crops recognizing specific cell membrane receptors such as cadherin, aminopeptidase-N, and alkaline phosphatase. Furthermore, some Cry toxins such as Cry4A, Cry4B, and Cry11A act synergistically with Cyt toxins against dipteran larvae vectors of human disease. Research developed with Cry proteins revealed that these toxins also could kill human cancer cells through the interaction with specific receptors. Parasporins are a small group of patented toxins that may or may not have insecticidal activity. These proteins could kill a wide variety of mammalian cancer cells by recognizing specific membrane receptors, just like Cry toxins do. Surface layer proteins (SLP), unlike the other proteins produced by Bt, are also produced by most bacteria and archaebacteria. It was recently demonstrated that SLP produced by Bt could interact with membrane receptors of insect and human cancer cells to kill them. Cyt toxins have a structure that is mostly unrelated to Cry toxins; thereby, other mechanisms of action have been reported to them. These toxins affect mainly mosquitoes that are vectors of human diseases like Anopheles spp (malaria), Aedes spp (dengue, zika, and chikungunya), and Culex spp (Nile fever and Rift Valley fever), respectively. In addition to the Cry, Cyt, and parasporins toxins produced during spore formation as inclusion bodies, Bt strains also produce Vip (Vegetative insecticidal toxins) and Sip (Secreted insecticidal proteins) toxins with insecticidal activity during their vegetative growth phase.

Determination of relationships among autochthonous grapevine varieties (Vitis vinifera L.) in the Northwest of the Iberian Peninsula by using microsatellite markers

2006 ◽  
Vol 53 (6) ◽  
pp. 1255-1261 ◽  
Author(s):  
Juan Pedro Martín ◽  
José luis Santiago ◽  
Olinda Pinto-Carnide ◽  
Fernanda Leal ◽  
María del Carmen Martínez ◽  
...  
Keyword(s):  
Vitis Vinifera ◽  
Microsatellite Markers ◽  
Iberian Peninsula ◽  
Vitis Vinifera L
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