Populational survey of arthropods on transgenic common bean expressing the rep gene from Bean golden mosaic virus (original) (raw)
Related papers
Plant Science, 2006
The rep gene of Bean golden mosaic virus (BGMV) is essential for virus replication. A mutated rep gene with amino acid codon change in the putative nucleoside triphosphate (NTP) binding motif D262R was created. Phaseolus vulgaris transformation was achieved with a vector that contained the mutated rep and bar genes. A total of 17 initial (T 0 ) transformants were analyzed. One line (M1/4) showed tolerance to glufosinate ammonium and partial resistance to the virus, that is, disease incidence depended on inoculation level. The incidence of BGMV increased with the increasing number of viruliferous whiteflies per plant, both in the transgenic and in the control plants. However, the number of symptomless plants was significantly higher in the transgenic group. The line M1/4 was studied during several generations and presented stability in the transgene loci and virus resistance. Southern blot analysis with genomic DNA of eight generations led to an estimate of two copies of the rep gene integrated at the same locus. RT-PCR analysis revealed the presence of both bar and rep genes transcripts. The mutated REP protein was present in amounts detectable by Western blot analysis in transgenic plants. #
The Environmental Effects of Genetically Modified Crops Resistant to Insects
Neotropical Entomology, 2002
Efeitos Ambientais de Culturas Geneticamente Modificadas Resistentes a Insetos RESUMO-Cultivares transgênicas de várias culturas estão sendo utilizadas em escala comercial em muitos países. A área dedicada ao cultivo com plantas transgênicas resistentes às pragas em todo o mundo alcançou 13 milhões de hectares em 2001. As cultivares transgênicas proporcionam benefícios, mas também apresentam riscos potenciais. As avaliações do seu impacto no ambiente são conduzidas antes da sua aprovação para uso comercial, como requerido pelas normas de biossegurança. Nesta revisão, serão discutidas as conseqüências ecológicas potenciais do uso comercial na agricultura de cultivares geneticamente modificadas que apresentam resistência aos insetos-pragas. Também serão discutidos os impactos ambientais causados pelas mudanças nas práticas agrícolas, identificando-se falhas e oportunidades de pesquisa, considerando-se essa nova ferramenta tecnológica. Os comentários e análises serão baseados no conhecimento atual que se tem dos riscos e beneficios do uso de cultivares resistentes a insetos, geneticamente modificadas, dentro do contexto dos programas de manejo integrado de pragas tradicionais. PALAVRAS-CHAVE: Planta transgênica, Bacillus thuringiensis, organismo não-alvo, fluxo gênico, biossegurança ABSTRACT-Transgenic crops are currently being cultivated on a commercial scale in many countries. The area devoted to transgenic pest resistant varieties worldwide reached 13 million hectares in 2001. These varieties offer valuable benefits but also pose potential risks. Assessments of their impact on the environment are conducted before they are approved for commercial use, as required by the regulatory biosafety frameworks. In this review, we discuss the potential ecological consequences of the commercial use in agriculture of genetically modified insect resistant crops. We also discuss the impacts caused by the change in agricultural practices, and attempt to identify gaps and possible opportunities for research, considering this new technological tool. We based our analysis and comments on the current knowledge of the risks and benefits of these genetically modified insect resistant crops, within the context of traditional insect management strategies.
Evaluation of disease severity caused by Bean golden mosaic virus in different bean cultivars
Canadian Journal of Plant Pathology, 2020
Common bean (Phaseolus vulgaris L.) can be affected by several viral diseases, including golden mosaic caused by the Bean golden mosaic virus (BGMV). When infected by BGMV, bean plants undergo major physiological changes, leading to a reduction or complete loss of productivity. This study aimed to evaluate and compare seven bean cultivars and lineages, as well as the legume calopo (Calopogonium mucunoides Desv.), for the severity of golden mosaic symptoms and BGMV titre following inoculation. The study was conducted in the greenhouse under controlled environmental conditions. Plants were inoculated with viruliferous whiteflies [Bemisia tabaci (Gennadius)], and evaluated for severity of disease symptoms at 7, 10, 15, 20, and 25 days after inoculation (DAI). The virus titre was measured by quantitative PCR (qPCR) analysis with primers specific for the virus coat protein gene. All bean genotypes were symptomatic for BGMV infection, but calopo was not. There were differences among the tested cultivars and lineages for the expression of symptoms. Differences in BGMV titre also were observed among the cultivars at 10 and 25 DAI. The bean cultivar 'Tangará' had a greater viral titre but exhibited lower symptom severity than the other cultivars. Calapo was tolerant to BGMV.
Insect resistance management in GM crops: past, present and future
Nature Biotechnology, 2005
Transgenic plants expressing insecticidal proteins from the bacterium Bacillus thuringiensis (Bt) were first commercialized in 1996 amid concern from some scientists, regulators and environmentalists that the widespread use of Bt crops would inevitably lead to resistance and the loss of a 'public good,' specifically, the susceptibility of insect pests to Bt proteins. Eight years later, Bt corn and cotton have been grown on a cumulative area >80 million ha worldwide. Despite dire predictions to the contrary, resistance to a Bt crop has yet to be documented, suggesting that resistance management strategies have been effective thus far. However, current strategies to delay resistance remain far from ideal. Eight years without resistance provides a timely opportunity for researchers, regulators and industry to reassess the risk of resistance and the most effective strategies to preserve Bt and other novel insect-resistant crops in development.
Designing experimental protocols to investigate the impact of GM crops on non-target arthropods
J Agr Sci, 2008
CHAPTER 1-INTRODUCTION Background Insect-Plant Interactions Life-history Other measures of population growth rates Where to next? CHAPTER 2-THE APPLICATION PROCESS AND EXAMPLES OF PREVIOUS APPLICATIONS SUBMITTED TO COGEM 15 Applications regarding GMOs received by COGEM 15 Problems highlighted by the above examples Concluding comments CHAPTER 3-POPULATION STUDIES Measuring mortality Sub-lethal effects GM plants Life table response experiments (LTRE) and the intrinsic rate of increase (r m) 29 Instantaneous / realised growth rates (r i) Comparing intrinsic (r m) and instantaneous (r i) rates of increase. Concluding comments CHAPTER 4-EXPERIMENTAL PROCEDURES FOR LABORATORY TESTING OF NON-TARGET ORGANISMS Determining experimental period Determining test concentration 40 General materials and methods common to all experiments 40 1. Predators: Development of assay protocol 41 2. Parasitoids: Development of assay protocol 43 3. Pollinators: Development of assay protocol 46 4. Soil dwelling organisms: Development of assay protocol Analysing results Concluding comments vi
Insect-resistant biotech crops and their impacts on beneficial arthropods
Philosophical Transactions of the Royal Society B: Biological Sciences, 2011
With a projected population of 10 billion by 2050, an immediate priority for agriculture is to achieve increased crop yields in a sustainable and cost-effective way. The concept of using a transgenic approach was realized in the mid-1990s with the commercial introduction of genetically modified (GM) crops. By 2010, the global value of the seed alone was US 11.2billion,withcommercialbiotechmaize,soyabeangrainandcottonvaluedatapproximatelyUS11.2 billion, with commercial biotech maize, soya bean grain and cotton valued at approximately US 11.2billion,withcommercialbiotechmaize,soyabeangrainandcottonvaluedatapproximatelyUS150 billion. In recent years, it has become evident that insect-resistant crops expressing δ -endotoxin genes from Bacillus thuringiensis have made a significant beneficial impact on global agriculture, not least in terms of pest reduction and improved quality. However, because of the potential for pest populations to evolve resistance, and owing to lack of effective control of homopteran pests, alternative strategies are being developed. Some of these are based on Bacillus spp. or other insect pathogens, while others are based on ...
Bean pod mottle virus Spread in Insect-Feeding-Resistant Soybean
Plant Disease, 2010
Redinbaugh, M. G., Molineros, J. E., Vacha, J., Berry, S. A., Hammond, R. B., Madden, L. V., and Dorrance, A. E. 2010. Bean pod mottle virus spread in insect-feeding-resistant soybean. Plant Dis. 94:265-270.
Status of Genetically Engineered Insect Pest Resistant Crops and Related Biosafety Concerns
Indian Journal of Plant Protection, 2007
The era of modern plant biotechnology has provided eco-friendly approaches for pest management by genetic engineering of plants for pest resistance particularly insects. Transgenic plants engineered to contain genes for pest resistance were first field tested in 1988 and started being grown commercially since 1995. From 1995–2006, the commercial planting of transgenic pest resistant plants has increased rapidly. Of this a large percentage is of pest resistant crops containing the Bacillus thuringiensis (Bt) gene, conferring protection from certain insect pests. Three commercial transgenic crops viz., cotton, maize and potato have so far been introduced with Bt genes for insect control. Many other crops are also being engineered to express the Bt toxin. In India, only Bt cotton (resistant against cotton bollworm) is approved with cry1Ac; cry1Ac & cry2Ab genes. Currently, about 300 institutions in India are engaged in research on transgenics, developing crops resistant to different pe...