The transfer of Bt insecticidal protein to higher tropic levels via a transgenic cotton, then beet armyworm (Lepidoptera: Noctuidae) and their natural enemies

2013 ◽  
Vol 146 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Chun-Xia Chen ◽  
Erzhong Wu ◽  
Yi-Zhong Yang ◽  
Hong-Hua Su
Keyword(s):  
Natural Enemies ◽  
Food Chain ◽  
Transgenic Cotton ◽  
The Body ◽  
Beet Armyworm ◽  
Insecticidal Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Bt Cotton ◽  
Bt Toxin ◽  
Lepidoptera Noctuidae

AbstractIn order to determine the transference of Bacillus thuringiensis Berliner (Bacillaceae) (Bt) insecticidal protein in the food chain, enzyme-linked immunosorbent assay was used to detect Bt insecticidal protein levels in transgenic Bt cotton (GK12, New variety 33B and SGK321), Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae) fed on the Bt cotton varieties, and two natural enemies of S. exigua, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and Microplitis pallidipes Szépligeti (Hymenoptera: Braconidae). The results showed that Bt insecticidal protein was found not only in cotton leaves, but also in the body and excrement of S. exigua and the bodies of both C. carnea and M. pallidipes. Bt toxin was detected in S. exigua larvae of all the examined instars (second, third, fourth, and fifth) that fed on transgenic cotton varieties and the Bt toxin level was the highest in the body of the second instar. In addition, the Bt toxin content in the excrement of the second instar was lower than that in the older ones. After the natural enemies C. carnea and M. pallidipes preyed/parasitised the S. exigua larvae that fed on transgenic cotton, Bt toxin was found in both the predator and parasite. This research indicates that Bt protein can be transferred through the food chain and to natural enemies of various predatory habits.

scholarly journals Management of the Beet Armyworm (Lepidoptera: Noctuidae) in Cotton: Role of Natural Enemies

1994 ◽  
Vol 77 (4) ◽  
pp. 440 ◽  
Author(s):  
John R. Ruberson ◽  
Gary A. Herzog ◽  
William R. Lambert ◽  
W. Joe Lewis
Keyword(s):  
Natural Enemies ◽  
Beet Armyworm ◽  
Lepidoptera Noctuidae

Assessment of Bt cotton genotypes for the Cry1Ac transgene and its expression

2015 ◽  
Vol 154 (1) ◽  
pp. 109-117 ◽  
Author(s):  
H. M. N. CHEEMA ◽  
A. A. KHAN ◽  
M. I. KHAN ◽  
U. ASLAM ◽  
I. A. RANA ◽  
...  
Keyword(s):  
Real Time ◽  
Significant Variation ◽  
Transgene Expression ◽  
Enzyme Linked Immunosorbent Assay ◽  
Optimum Level ◽  
Bt Cotton ◽  
Gm Crop ◽  
Bt Toxin ◽  
Cotton Genotypes ◽  
The Impact

SUMMARYGenetically modified (GM) plants expressing Bt toxin provide protection against lepidopteran pests. The only GM crop in Pakistan is Bt cotton, which was illegally imported and adopted rapidly by cotton producers. Farmers gained access to the seed of many unapproved Bt genotypes before the matter was picked up and formal approval granted by the relevant governmental agencies. The present study was conducted to evaluate the samples of Bt cotton, collected from farmers and seed dealer, for transgene integration and expression. Seeds of 52 cotton genotypes, labelled as Bt, were collected from various farmers and seed dealers. An immunoblot strip test was carried out, which showed that only 0·86 of the samples collected were synthesizing Cry1Ac toxin. According to multiplexed polymerase chain reaction (PCR) results, 0·86 of the genotypes tested were positive for the Mon531 event (an ‘event’ is a specific genetic modification in a specific species) and 0·14 were negative for any transgene. Transcript analysis of transgenes in positive genotypes by real-time Rt-PCR confirmed the synthesis of mRNA in all genotypes but with significant variation. The concentration of Bt toxin revealed by enzyme linked immunosorbent assay (ELISA) showed that only 0·02 genotypes had the reported optimum level. The real-time PCR and ELISA results further confirmed the attenuation of transgene expression at transcriptional and translational level by various internal and external factors. The same type of event was found in all genotypes, with significant variation in toxin level, revealing the impact of genetic background on transgene expression. The findings support the recommendation to improve the existing quality criteria for transgenic cotton variety approval and certification in Pakistan, with the inclusion of toxin concentration in the list of parameters to be considered.

Development of Spodoptera exigua and Helicoverpa zea (Lepidoptera: Noctuidae) on Transgenic Cotton Containing CrylAc Insecticidal Protein

2000 ◽  
Vol 35 (4) ◽  
pp. 360-372 ◽  
Author(s):  
Muhammad Ashfaq ◽  
S. Y. Young ◽  
R. W. McNew
Keyword(s):  
Helicoverpa Zea ◽  
Spodoptera Exigua ◽  
Larval Mortality ◽  
Transgenic Cotton ◽  
Larval Period ◽  
Pupal Weight ◽  
Feeding Time ◽  
Bt Cotton ◽  
Cotton Pests ◽  
Lepidoptera Noctuidae

The effects of transgenic Bacillus thuringiensis (Bt)-cotton on three instars of Spodoptera exigua (Hübner) and Helicoverpa zea (Boddie) were studied. First, third and fifth instars were fed field-collected Bt-cotton leaves for 1, 2, 3, 4 and 7 d or until pupation, and then transferred to artificial diet. Larval mortality at pupation, length of larval and pupal periods, pupal weights and survival time from hatch to adult were recorded for regular and Bt-cotton. Larval mortality at pupation in S. exigua fed Bt-cotton was low for all instars exposed and feeding periods on Bt-cotton. The mortality in H. zea was high for first and third instars and significantly increased with the increase in feeding period on Bt-cotton (P < 0.05). The length of larval period increased in both species when first and third instars but not fifth instars were fed Bt-cotton. In H. zea, the larval period increased when larvae were on Bt-cotton leaves for only 2 d. Pupal weight was reduced with an increase in feeding time on Bt-cotton in all three instars in both species. An increase in length of feeding time on Bt-cotton reduced survival to adults in both species on Bt-cotton in first and third instars but not in fifth instars. Survival to adults was much lower in H. zea than S. exigua for all instars exposed and feeding periods on Bt-cotton. These results demonstrate the large differences in effectiveness of Bt-cotton against lepidopteran cotton pests, as well as the adverse effects on larvae developing on Bt-cotton.

Preexisting resistance in cotton bollworm increases the risk of resistance to the concurrently planted Bt cotton and Bt maize

2020 ◽  
Author(s):  
Wenhui Wang ◽  
Feng Xu ◽  
Yunxin Huang ◽  
Hongqiang Feng ◽  
Peng Wan
Keyword(s):  
Population Genetic ◽  
Genetic Model ◽  
Resistance Management ◽  
Northern China ◽  
Cotton Bollworm ◽  
Bt Cotton ◽  
Bt Maize ◽  
Bt Toxin ◽  
Lepidoptera Noctuidae ◽  
Common Target

Abstract Background Transgenic maize expressing toxins derived from the bacterium Bacillus thuringiensis (Bt) may be commercially planted in northern China where Bt cotton has been planted for more than two decades. While Bt maize brings additional benefits for insect control, it complicates the resistance management of cotton bollworm (CBW), Helicoverpa armigera (Lepidoptera, Noctuidae), a common target of Bt cotton and Bt maize. Results We used a two-locus population genetic model to assess the risk of resistance in CBW when Bt cotton and Bt maize are planted concurrently. Results of model simulations showed that planting Bt maize together with Bt cotton significantly increases the risk of resistance if Bt cotton and Bt maize share a similar Bt toxin. The risk of resistance is higher in the case of one-toxin Bt maize than in the case of two-toxin Bt maize. Parameters associated with the preexisting resistance in CBW all could impact on the risk of resistance but with different extents. Among them, the most notable ones are the dominance of resistance and fitness cost, which can dramatically affect the risk of resistance, especially when the proportion of natural refuges is reduced. Conclusions We concluded that the preexisting resistance in CBW to Bt cotton can significantly increase the risk of resistance when Bt maize and Bt cotton are planted concurrently and that using two-toxin Bt cotton and maize instead of one-toxin ones are needed in order to reduce the risk of resistance.

scholarly journals Bacterial Microbiota of Field-Collected Helicoverpa zea (Lepidoptera: Noctuidae) from Transgenic Bt and Non-Bt Cotton

2021 ◽  
Vol 9 (4) ◽  
pp. 878
Author(s):  
Jean M. Deguenon ◽  
Anirudh Dhammi ◽  
Loganathan Ponnusamy ◽  
Nicholas V. Travanty ◽  
Grayson Cave ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Cotton Bollworm ◽  
Bt Cotton ◽  
Bacterial Populations ◽  
Bt Toxin ◽  
Molecular Approaches ◽  
Bacterial Microbiota ◽  
Bacterium Bacillus ◽  
The Impact ◽  
Lepidoptera Noctuidae

The bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), is an important agricultural pest in U.S. cotton and is managed using transgenic hybrids that produce insecticidal proteins from the bacterium, Bacillus thuringiensis (Bt). The reduced efficacy against H. zea caterpillars of Bt plants expressing Cry toxins is increasing in the field. In a first step towards understanding Bt cotton–bollworm–microbiota interactions, we investigated the internal bacterial microbiota of second–third stadium H. zea collected in the field from non-Bt versus Bt (WideStrike) cotton in close proximity (in North Carolina, USA). The bacterial populations were analyzed using culture-dependent and -independent molecular approaches. We found that WideStrike samples had a higher bacterial density and diversity per larva than insects collected from non-Bt cotton over two field seasons: 8.42 ± 0.23 and 5.36 ± 0.75 (log10 colony forming units per insect) for WideStrike compared to 6.82 ± 0.20 and 4.30 ± 0.56 for non-Bt cotton for seasons 1 and 2, respectively. Fifteen phyla, 103 families, and 229 genera were identified after performing Illumina sequencing of the 16S rRNA. At the family level, Enterobacteriaceae and Enterococcaceae were the most abundant taxa. The Enterococcaceae family was comprised mostly of Enterococcus species (E. casseliflavus and another Enterococcus sp.). Members of the Enterococcus genus can acidify their environment and can potentially reduce the alkaline activation of some Bt toxins. These findings argue for more research to better understand the role of cotton–bollworm–bacteria interactions and the impact on Bt toxin caterpillar susceptibility.

Efficacy of Transgenic Cotton Expressing Cry1Ac and Cry1F Insecticidal Protein Against Heliothines (Lepidoptera: Noctuidae)

2008 ◽  
Vol 101 (6) ◽  
pp. 1950-1959 ◽  
Author(s):  
M. Willrich Siebert ◽  
S. Nolting ◽  
B. R. Leonard ◽  
L. B. Braxton ◽  
J. N. All ◽  
...  
Keyword(s):  
Transgenic Cotton ◽  
Insecticidal Protein ◽  
Lepidoptera Noctuidae

scholarly journals Evaluación del comportamiento del complejo Spodoptera con la introducción de algodón transgénico al Tolima, Colombia

2009 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Oscar Santos Amaya ◽  
Oscar Delgado Restrepo ◽  
Jorge Argüelles ◽  
Elizabeth Aguilera Garramuño
Keyword(s):  
Spodoptera Frugiperda ◽  
Developmental Stages ◽  
Statistical Significance ◽  
Central Area ◽  
Transgenic Cotton ◽  
Complex Species ◽  
Bt Toxin ◽  
Significant Relationships ◽  
Cotton Plants ◽  
Lepidoptera Noctuidae

<p>Se comparó el comportamiento de las larvas del complejo <em>Spodoptera </em>(Lepidoptera: Noctuidae) entre lotes comerciales de algodón convencional y genéticamente modificado (Cry1Ac) en el Tolima, Colombia. Se evaluaron 83 cultivos de algodón (315 ha) y sus respectivos refugios (12,6 ha) en tres estados de desarrollo: vegetativo, reproductivo y maduración. En cada visita se seleccionaron al azar siete plantas por hectárea y se registró el número de larvas de <em>Spodoptera frugiperda, S. ornithogalli y S. sunia, </em>el tamaño (pequeñas &lt; 0,5 cm, medianas entre 0,5 y 1,5 cm, y grandes &gt; 1,5 cm) y su ubicación en la plantas (hojas, flores y cápsulas). En el análisis de los datos se utilizó una prueba de dependencia no paramétrica de Ji-cuadrado (<em>X</em><em>2</em>). La dependencia del porcentaje de larvas del complejo <em>Spodoptera </em>por planta fue significativamente mayor (0,0021) en las plantas transgénicas (11,98% SE 4,03) que en las convencionales (9,13% SE 3,08). Este patrón se conservó al analizar los datos por especie y estado de desarrollo de la planta. En ambos materiales genéticos se registró una dependencia espacial significativa (0,0001) entre las especies observadas y las estructuras de la planta: <em>S. frugiperda </em>predominó en flores y cápsulas, <em>S. ornithogalli</em>, en hojas y flores y <em>S. sunia</em>, en hojas. No hubo una dependencia significativa entre los materiales genéticos y las estructuras vegetales con el tamaño de las larvas. Se registraron larvas de todos los tamaños en flores y cápsulas, estructuras donde la expresión de la proteína Bt es baja.  </p><p> </p><p><strong>Evaluation of <em>Spodoptera </em>complex behavior with the introduction of transgenic cotton in Tolima, Colombia</strong> </p><p>In this study a record and an evaluation of the <em>Spodoptera </em>larvae complex (Lepidoptera: Noctuidae) of commercial transgenic cotton (Cry1Ac) planted in the central area of Tolima, Colombia were registered. During three plant developmental stages: vegetative, reproductive and maturity, 83 commercial plots with areas ranging from 1 to 10 hectares, were evaluated. Spodoptera complex (<em>Spodoptera frugiperda, S. ornithogalli y S. sunia</em>) activity was evaluated in 315 ha, sampling seven plants per hectare, including refuges (12,6 ha), taking into account three different larvae sizes, small &lt; 0.5 cm, medium &gt; 0.5 and &lt; 1.5 cm and large &gt; 1.5 cm, as well as their location in the plant (leaf, flower and structure). There were statistically significant relationships between the larvae incidence (percentage of cotton plants with <em>Spodoptera </em>larvae present) and the different cotton genetic materials, with a significant higher larvae incidence in the transgenic plants (11,98% SE 4,03) than in conventional plants (9,13% SE 3.08) (0,0021*). This tendency was also observed among <em>Spodoptera </em>complex species, both genetic materials and the three plant developmental stages. <em>S. frugiperda </em>prevailed in flowers and capsules, <em>S. ornithogalli </em>in leaves and flowers<em>; and S. sunia </em>in leaves. This pattern was observed in both genetic materials with statistical significance (0.0001*). Larvae of all sizes were recorded in plants of both genetic materials; although there was no statistically significative dependency. Finally, there were small, medium and large <em>S. frugiperda </em>larvae in flowers and capsules, structures where the Bt toxin expression is the lowest in the plant. </p>

Sign in / Sign up

Export Citation Format

Share Document