scholarly journals Rapid spread of a densovirus in a major crop pest following wide-scale adoption of Bt-cotton in China

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yutao Xiao ◽  
Wenjing Li ◽  
Xianming Yang ◽  
Pengjun Xu ◽  
Minghui Jin ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Data ◽  
Insect Pests ◽  
Bt Cotton ◽  
Rna Seq ◽  
Bt Crops ◽  
Crop Pests ◽  
Crop Pest ◽  
Rapid Spread ◽  
Wide Scale

Bacillus thuringiensis (Bt) crops have been widely planted and the effects of Bt-crops on populations of the target and non-target insect pests have been well studied. However, the effects of Bt-crops exposure on microorganisms that interact with crop pests have not previously been quantified. Here, we use laboratory and field data to show that infection of Helicoverpa armigera with a densovirus (HaDV2) is associated with its enhanced growth and tolerance to Bt-cotton. Moreover, field monitoring showed a much higher incidence of cotton bollworm infection with HaDV2 in regions cultivated with Bt-cotton than in regions without it, with the rate of densovirus infection increasing with increasing use of Bt-cotton. RNA-seq suggested tolerance to both baculovirus and Cry1Ac were enhanced via the immune-related pathways. These findings suggest that exposure to Bt-crops has selected for beneficial interactions between the target pest and a mutualistic microorganism that enhances its performance on Bt-crops under field conditions.

scholarly journals Rapid spread of a symbiotic virus in a major crop pest following wide-scale adoption of Bt-cotton in China

2021 ◽  
Author(s):  
Yutao Xiao ◽  
Wenjing Li ◽  
Xianming Yang ◽  
Pengjun Xu ◽  
Minghui Jin ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Data ◽  
Insect Pests ◽  
Bt Cotton ◽  
Rna Seq ◽  
Bt Crops ◽  
Crop Pest ◽  
Rapid Spread ◽  
Wide Scale ◽  
Symbiotic Microorganism

AbstractBacillus thuringiensis (Bt) crops have been widely planted and the effects of Bt-crops on populations of the target and non-target insect pests were well studied. However, the effects of Bt-crops exposure on microorganisms that interact with crop pests haven’t previously been quantified. Here, we use laboratory and field data to show that infection of Helicoverpa armigera with a symbiotic densovirus (HaDV2) is associated with its enhanced growth and resistance to Bt-cotton. Moreover, field monitoring showed a much higher incidence of cotton bollworm infection with HaDV2 in regions cultivated with Bt-cotton than in regions without it, with the rate of densovirus infection increasing with increasing use of Bt-cotton. RNA-seq suggested resistance to both baculovirus and Cry1Ac were enhanced via the immune-related pathways. These suggest that the exposure to Bt-crops has selected for beneficial interactions between the target pest and a symbiotic microorganism that enhances its performance on Bt-crops under field conditions.

scholarly journals Bacillus thuringiensis Vip3Aa Toxin Resistance in Heliothis virescens (Lepidoptera: Noctuidae)

2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Brian R. Pickett ◽  
Asim Gulzar ◽  
Juan Ferré ◽  
Denis J. Wright
Keyword(s):  
Bacillus Thuringiensis ◽  
Heliothis Virescens ◽  
Insect Pests ◽  
Management Strategies ◽  
Resistance Management ◽  
Cross Resistance ◽  
Inheritance Of Resistance ◽  
Resistant Parent ◽  
Bt Crops ◽  
Content Type

ABSTRACT Laboratory selection with Vip3Aa of a field-derived population of Heliothis virescens produced >2,040-fold resistance in 12 generations of selection. The Vip3Aa-selected (Vip-Sel)-resistant population showed little cross-resistance to Cry1Ab and no cross-resistance to Cry1Ac. Resistance was unstable after 15 generations without exposure to the toxin. F1 reciprocal crosses between Vip3Aa-unselected (Vip-Unsel) and Vip-Sel insects indicated a strong paternal influence on the inheritance of resistance. Resistance ranged from almost completely recessive (mean degree of dominance [h] = 0.04 if the resistant parent was female) to incompletely dominant (mean h = 0.53 if the resistant parent was male). Results from bioassays on the offspring from backcrosses of the F1 progeny with Vip-Sel insects indicated that resistance was due to more than one locus. The results described in this article provide useful information for the insecticide resistance management strategies designed to overcome the evolution of resistance to Vip3Aa in insect pests. IMPORTANCE Heliothis virescens is an important pest that has the ability to feed on many plant species. The extensive use of Bacillus thuringiensis (Bt) crops or spray has already led to the evolution of insect resistance in the field for some species of Lepidoptera and Coleoptera. The development of resistance in insect pests is the main threat to Bt crops. The effective resistance management strategies are very important to prolong the life of Bt plants. Lab selection is the key step to test the assumption and predictions of management strategies prior to field evaluation. Resistant insects offer useful information to determine the inheritance of resistance and the frequency of resistance alleles and to study the mechanism of resistance to insecticides.

Triple Helix Model of Innovation and the Politics of Genetically Modified Crops: Cases of Bt Cotton and Bt Brinjal in India

2017 ◽  
Vol 16 (4) ◽  
pp. 434-460 ◽  
Author(s):  
Madhulika Kumari ◽  
Sambit Mallick
Keyword(s):  
Bacillus Thuringiensis ◽  
Triple Helix ◽  
Genetically Modified ◽  
Genetically Modified Crops ◽  
Bt Cotton ◽  
Bt Crops ◽  
Triple Helix Model ◽  
Private Research ◽  
Research Questions ◽  
The Government

The construal of genetically modified (gm) crops is not just scientific or technological, but also inherently political. This article attempts to understand the implications of proprietary technologies in agriculture in India where two gm crops namely Bacillus thuringiensis (Bt) cotton and Bacillus thuringiensis (Bt) brinjal are analyzed. It critically examines how different normative institutional frameworks and ideologies are deeply embedded in the way diverse actors select their research questions. Further, an attempt is made to unfurl the debates on the policies of biotechnology, in general and Bt crops, in particular. It then moves onto capturing the networking between the government, academia and industry with reference to gm crops, particularly Bt cotton and Bt brinjal. In-depth personal interviews with 81 plant biotechnologists in the government, academic, and private research and development (R&D) institutions in India were conducted to ascertain the views of various stakeholders about Bt crops in agriculture in India.

scholarly journals Insect resistance management in Bacillus thuringiensis cotton by MGPS (multiple genes pyramiding and silencing)

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Muhammad Mubashar ZAFAR ◽  
Abdul RAZZAQ ◽  
Muhammad Awais FAROOQ ◽  
Abdul REHMAN ◽  
Hina FIRDOUS ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Crop Protection ◽  
High Dose ◽  
Bt Cotton ◽  
Artificial Chromosomes ◽  
Cotton Pests ◽  
Multiple Genes ◽  
Bt Toxins ◽  
Evolution Of Resistance

AbstractThe introduction of Bacillus thuringiensis (Bt) cotton has reduced the burden of pests without harming the environment and human health. However, the efficacy of Bt cotton has decreased due to field-evolved resistance in insect pests over time. In this review, we have discussed various factors that facilitate the evolution of resistance in cotton pests. Currently, different strategies like pyramided cotton expressing two or more distinct Bt toxin genes, refuge strategy, releasing of sterile insects, and gene silencing by RNAi are being used to control insect pests. Pyramided cotton has shown resistance against different cotton pests. The multiple genes pyramiding and silencing (MGPS) approach has been proposed for the management of cotton pests. The genome information of cotton pests is necessary for the development of MGPS-based cotton. The expression cassettes against various essential genes involved in defense, detoxification, digestion, and development of cotton pests will successfully obtain favorable agronomic characters for crop protection and production. The MGPS involves the construction of transformable artificial chromosomes, that can express multiple distinct Bt toxins and RNAi to knockdown various essential target genes to control pests. The evolution of resistance in cotton pests will be delayed or blocked by the synergistic action of high dose of Bt toxins and RNAi as well as compliance of refuge requirement.

Behavior-based control of insect crop pests

2018 ◽  
Author(s):  
Sandra A. Allan
Keyword(s):  
Insect Pests ◽  
Control Strategies ◽  
Insect Behavior ◽  
Life Cycles ◽  
Economic Damage ◽  
Mass Trapping ◽  
Ecological Traits ◽  
Crop Pests ◽  
Effective Strategies ◽  
Crop Development

Manipulation of insect behavior can provide the foundation for effective strategies for control of insect crop pests. A detailed understanding of life cycles and the behavioral repertoires of insect pests is essential for development of this approach. A variety of strategies have been developed based on behavioral manipulation and include mass trapping, attract-and-kill, auto-dissemination, mating and host plant location disruption, and push-pull. Insight into application of these strategies for insect pests within Diptera, Lepidoptera, Coleoptera, and Hemiptera/Thysanoptera are provided, but first with an overview of economic damage and traditional control approaches, and overview of relevant behavioral/ecological traits. Then examples are provided of how these different control strategies are applied for each taxonomic group. The future of these approaches in the context of altered crop development for repellency or as anti-feedants, the effects of climate change and the risks of behaviorally-based methods are discussed.

scholarly journals Retargeting of the Bacillus thuringiensis toxin Cyt2Aa against hemipteran insect pests

2013 ◽  
Vol 110 (21) ◽  
pp. 8465-8470 ◽  
Author(s):  
N. P. Chougule ◽  
H. Li ◽  
S. Liu ◽  
L. B. Linz ◽  
K. E. Narva ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Bacillus Thuringiensis Toxin ◽  
Hemipteran Insect

Monitor surveying for migrant insect pests

1973 ◽  
Vol 7 (3) ◽  
pp. 109-116 ◽  
Author(s):  
L R Taylor
Keyword(s):  
Population Dynamics ◽  
Insect Pests ◽  
Spatial Dimension ◽  
Effective Control ◽  
Crop Pests ◽  
Insect Populations ◽  
Insect Survey ◽  
Local Assessment

Effective control of erratic crop pests requires accurate timing of treatments, and the dynamics of insect populations are inadequately understood. Aerial monitoring for many species simultaneously, instead of sampling each crop separately, enables the Rothamsted Insect Survey to provide accurate, quantitative, synoptic information on current levels of pest populations; this gives continuity to local assessment for advisory purposes, and adds a spatial dimension to population dynamics.

scholarly journals RNA Modification Level Estimation with pulseR

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 619
Author(s):  
Etienne Boileau ◽  
Christoph Dieterich
Keyword(s):  
Experimental Approach ◽  
High Efficiency ◽  
Rna Modification ◽  
Model Parameters ◽  
Metabolic Labeling ◽  
Rna Seq ◽  
Rna Modifications ◽  
Log Odds ◽  
Pros And Cons ◽  
Wide Scale

RNA modifications regulate the complex life of transcripts. An experimental approach called LAIC-seq was developed to characterize modification levels on a transcriptome-wide scale. In this method, the modified and unmodified molecules are separated using antibodies specific for a given RNA modification (e.g., m6A). In essence, the procedure of biochemical separation yields three fractions: Input, eluate, and supernatent, which are subjected to RNA-seq. In this work, we present a bioinformatics workflow, which starts from RNA-seq data to infer gene-specific modification levels by a statistical model on a transcriptome-wide scale. Our workflow centers around the pulseR package, which was originally developed for the analysis of metabolic labeling experiments. We demonstrate how to analyze data without external normalization (i.e., in the absence of spike-ins), given high efficiency of separation, and how, alternatively, scaling factors can be derived from unmodified spike-ins. Importantly, our workflow provides an estimate of uncertainty of modification levels in terms of confidence intervals for model parameters, such as gene expression and RNA modification levels. We also compare alternative model parametrizations, log-odds, or the proportion of the modified molecules and discuss the pros and cons of each representation. In summary, our workflow is a versatile approach to RNA modification level estimation, which is open to any read-count-based experimental approach.

scholarly journals Bt crops and insect pests

2012 ◽  
Vol 3 (3) ◽  
pp. 139-139 ◽  
Author(s):  
Aaron J. Gassmann ◽  
William D. Hutchison
Keyword(s):  
Insect Pests ◽  
Bt Crops

scholarly journals How E-Learning Deals with Higher Education during the Pandemic in Indonesia

2020 ◽  
Vol 13 (2) ◽  
pp. 51
Author(s):  
Andhi Dwi Nugroho
Keyword(s):  
Higher Education ◽  
Online Learning ◽  
Qualitative Method ◽  
World Wide ◽  
Learning Processes ◽  
State Universities ◽  
Rapid Spread ◽  
E Learning ◽  
Wide Scale ◽  
Descriptive Qualitative

AbstractThe purpose of this study is to investigate the obstacles of e-learning, especially for students, and to find out students' perception in facing e-learning during coronavirus disease pandemic (covid-19). The rapid spread of coronavirus urges universities on a world-wide scale to do e-learning, including universities in Indonesia. This study uses online interviews and questionnaires to obtain the data, and descriptive qualitative method is used to analyse the data. The respondents in this study are 126 students with different majors from 21 universities in all across Indonesia, consisting of 6 state universities and 15 private ones. The results of the study reveal that e-learning has been carried out by universities in the country. It also shows there are several aspects such as the availability of online learning facilities, the use of facilities, learning processes, and some more points that need to reconsider or to optimize conducting the e-learning for the long term.Keywords: e-learning; students; pandemic

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