scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Insect resistance to Bt crops: lessons from the first billion acres

TL;DR: Field outcomes support theoretical predictions that factors delaying resistance include recessive inheritance of resistance, low initial frequency of resistance alleles, abundant refuges of non-Bt host plants and two-toxin Bt crops deployed separately from one-t toxin BT crops.
Abstract: Evolution of resistance in pests can reduce the effectiveness of insecticidal proteins from Bacillus thuringiensis (Bt) produced by transgenic crops We analyzed results of 77 studies from five continents reporting field monitoring data for resistance to Bt crops, empirical evaluation of factors affecting resistance or both Although most pest populations remained susceptible, reduced efficacy of Bt crops caused by field-evolved resistance has been reported now for some populations of 5 of 13 major pest species examined, compared with resistant populations of only one pest species in 2005 Field outcomes support theoretical predictions that factors delaying resistance include recessive inheritance of resistance, low initial frequency of resistance alleles, abundant refuges of non-Bt host plants and two-toxin Bt crops deployed separately from one-toxin Bt crops The results imply that proactive evaluation of the inheritance and initial frequency of resistance are useful for predicting the risk of resistance and improving strategies to sustain the effectiveness of Bt crops
Citations
More filters
Journal ArticleDOI
TL;DR: Current information on development, use and future directions of insect-specific viruses, bacteria, fungi and nematodes as components of integrated pest management strategies for control of arthropod pests of crops, forests, urban habitats, and insects of medical and veterinary importance is presented.

926 citations


Cites background from "Insect resistance to Bt crops: less..."

  • ...…Bt microbial pesticides, Bt crops also are 942 susceptible to resistance problems and a number of cases have been reported, particularly with 943 first generation single gene constructs (Rhaman et al., 2004, Shelton et al., 2007; Tabashnik, 944 2008; Tabashnik et al., 2008a, 2008b, 2009, 2013)....

    [...]

Journal ArticleDOI
07 Nov 2019-Nature
TL;DR: The potential of plant sciences to address post-Green Revolution challenges in agriculture is considered and emerging strategies for enhancing sustainable crop production and resilience in a changing climate are explored.
Abstract: The current trajectory for crop yields is insufficient to nourish the world’s population by 20501. Greater and more consistent crop production must be achieved against a backdrop of climatic stress that limits yields, owing to shifts in pests and pathogens, precipitation, heat-waves and other weather extremes. Here we consider the potential of plant sciences to address post-Green Revolution challenges in agriculture and explore emerging strategies for enhancing sustainable crop production and resilience in a changing climate. Accelerated crop improvement must leverage naturally evolved traits and transformative engineering driven by mechanistic understanding, to yield the resilient production systems that are needed to ensure future harvests. Genetic strategies for improving the yield and sustainability of agricultural crops, and the resilience of crops in the face of biotic and abiotic stresses contingent on projected climate change, are evaluated.

639 citations


Cites background from "Insect resistance to Bt crops: less..."

  • ...are involved in non-photochemical quenching (NPQ) (the dissipation of excess excitation energy as heat)(116); (2) altering the CO2 response of stomata or the density of stomata on the leaf surface to increase the efficiency of water use(120,122,123); (3) increasing the capacity for mesophyll conductance of CO2 (105); (4) improving the energy efficiency of carbon metabolism by altering mitochondrial enzymes(155); (5) optimizing investment in light collection(105);...

    [...]

Journal ArticleDOI
TL;DR: It is suggested that the combination of disease resistance genes with other practices for pathogen control (pesticides, farming practices) may be a relevant management strategy to slow down the evolution of virulent pathogen genotypes.
Abstract: The efficacy of disease resistance genes in plants decreases over time because of the selection of virulent pathogen genotypes. A key goal of crop protection programs is to increase the durability of the resistance conferred by these genes. The spatial and temporal deployment of plant disease resistance genes is considered to be a major factor determining their durability. In the literature, four principal strategies combining resistance genes over time and space have been considered to delay the evolution of virulent pathogen genotypes: cultivars mixture, rotation, landscape deployment, pyramiding. We reviewed this literature with the aim of determining which deployment strategy results in the greatest durability of resistance genes. Although theoretical and empirical studies comparing deployment strategies of more than one resistance gene are very scarce, they suggest that the overall durability of disease resistance genes can be increased by combining their presence in the same plant (pyramiding). Retrospective analyses of field monitoring data also suggest that the pyramiding of disease resistance genes within a plant is the most durable strategy. By extension, we suggest that the combination of disease resistance genes with other practices for pathogen control (pesticides, farming practices) may be a relevant management strategy to slow down the evolution of virulent pathogen genotypes.

554 citations

Journal ArticleDOI
TL;DR: A thorough phylogenetic analysis of the seven arthropod and human ABC protein subfamilies is conducted, to infer orthologous relationships that might suggest conserved function of ABC transporters in arthropods.

442 citations


Cites background from "Insect resistance to Bt crops: less..."

  • ...The mode of action of Bt toxins (and the resistance mechanisms to Bt in insects) are of huge commercial value, given that millions of hectares have been planted with transgenic Bt crops such as maize and cotton (Tabashnik et al., 2013)....

    [...]

Journal ArticleDOI
TL;DR: Global monitoring data reported during the first two decades of transgenic crops was analyzed, with each case representing the responses of one pest species in one country to one insecticidal protein from Bacillus thuringiensis (Bt).
Abstract: Transgenic crops have revolutionized insect pest control, but their effectiveness has been reduced by evolution of resistance in pests. We analyzed global monitoring data reported during the first two decades of transgenic crops, with each case representing the responses of one pest species in one country to one insecticidal protein from Bacillus thuringiensis (Bt). The cases of pest resistance to Bt crystalline (Cry) proteins produced by transgenic crops increased from 3 in 2005 to 16 in 2016. By contrast, in 17 other cases there was no decrease in pest susceptibility to Bt crops, including the recently introduced transgenic corn that produces a Bt vegetative insecticidal protein (Vip). Recessive inheritance of pest resistance has favored sustained susceptibility, but even when inheritance is not recessive, abundant refuges of non-Bt host plants have substantially delayed resistance. These insights may inform resistance management strategies to increase the durability of current and future transgenic crops.

404 citations

References
More filters
Journal ArticleDOI
TL;DR: It is demonstrated that ingestion of double-stranded (ds)RNAs supplied in an artificial diet triggers RNA interference in several coleopteran species, most notably the western corn rootworm Diabrotica virgifera virgifiera LeConte, suggesting that the RNAi pathway can be exploited to control insect pests via in planta expression of a dsRNA.
Abstract: Commercial biotechnology solutions for controlling lepidopteran and coleopteran insect pests on crops depend on the expression of Bacillus thuringiensis insecticidal proteins1,2, most of which permeabilize the membranes of gut epithelial cells of susceptible insects3 However, insect control strategies involving a different mode of action would be valuable for managing the emergence of insect resistance Toward this end, we demonstrate that ingestion of double-stranded (ds)RNAs supplied in an artificial diet triggers RNA interference in several coleopteran species, most notably the western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte This may result in larval stunting and mortality Transgenic corn plants engineered to express WCR dsRNAs show a significant reduction in WCR feeding damage in a growth chamber assay, suggesting that the RNAi pathway can be exploited to control insect pests via in planta expression of a dsRNA

1,545 citations

Journal ArticleDOI
TL;DR: Theoretical and practical issues involved in implementing strategies to delay pest adaptation to insecticidal cultivars are reviewed and emphasis is placed on examining the "high dose"/refuge strategy that has become the goal of industry and regulatory authorities.
Abstract: ▪ Abstract This review examines potential impacts of transgenic cultivars on insect population dynamics and evolution. Experience with classically bred, insecticidal cultivars has demonstrated that a solid understanding of both the target insect's ecology and the cultivar's performance under varied field conditions will be essential for predicting area-wide effects of transgenic cultivars on pest and natural enemy dynamics. This experience has also demonstrated the evolutionary capacity of pests for adaptive response to insecticidal traits in crops. Biochemical and genetic studies of insect adaptation to the Bacillus thuringiensis (Bt) toxins expressed by currently marketed transgenic cultivars indicate a high risk for rapid adaptation if these cultivars are misused. Theoretical and practical issues involved in implementing strategies to delay pest adaptation to insecticidal cultivars are reviewed. Emphasis is placed on examining the “high dose”/refuge strategy that has become the goal of industry and reg...

1,327 citations

Journal ArticleDOI
TL;DR: A cytochrome P450 gene (CYP6AE14) is identified from cotton bollworm, which permits this herbivore to tolerate otherwise inhibitory concentrations of the cotton metabolite, gossypol, and its expression correlates with larval growth when gOSSypol is included in the diet.
Abstract: We identify a cytochrome P450 gene (CYP6AE14) from cotton bollworm (Helicoverpa armigera), which permits this herbivore to tolerate otherwise inhibitory concentrations of the cotton metabolite, gossypol. CYP6AE14 is highly expressed in the midgut and its expression correlates with larval growth when gossypol is included in the diet. When larvae are fed plant material expressing double-stranded RNA (dsRNA) specific to CYP6AE14, levels of this transcript in the midgut decrease and larval growth is retarded. Both effects are more dramatic in the presence of gossypol. As a glutathione-S-transferase gene (GST1) is silenced in GST1 dsRNA-expressing plants, feeding insects plant material expressing dsRNA may be a general strategy to trigger RNA interference and could find applications in entomological research and field control of insect pests.

1,150 citations

Journal ArticleDOI
TL;DR: Insecticides derived from the common soil bacterium Bacillus thuringiensis (Bt) are becoming increasingly important for pest management as discussed by the authors, as mounting concerns about environmental hazards and widespread resistance in pest populations are reducing the value of conventional synthetic insecticides.
Abstract: Insecticides derived from the common soil bacterium Bacillus thuringiensis (Bt) are becoming increasingly important for pest management. Insecticidal crystal proteins (also called 8-endotoxins) from Bt are extremely toxic to certain pests, yet cause little or no hann to humans, most beneficial insects, and other nontarget organisms (19, 40). After proteolytic activation in the insect midgut, Bt toxins bind to the brush border membrane of the midgut epithelium and create pores that cause cells to swell and lyse (55). Technical innovations, including expression of Bt toxin genes in transgenic crop plants and transgenic bacteria, should increase the usefulness of Bt (6, 12, 35, 46, 91, 94, 109, 116). At the same time, mounting concerns about environmental hazards and widespread resistance in pest populations are reducing the value of conventional synthetic insecticides. Because Bt had been used commercially for more than two decades without reports of substantial resistance development in open field popu­ lations, some scientists had presumed that evolution of resistance was unlikely (21, 89). However, resistance to Bt was documented recently in field populations of diamondback moth in Hawaii, the continental US, and Asia (36, 42, 92a, 128, 129, 131, 138, 146, 148, 151). These reports confirmed suspicions raised by the results of laboratory selection for resistance to Bt in several major pests (102, 104, 135). Scientists in industry, government, and academia now recognize evolution of resistance to Bt in pests as the greatest threat to the continued success of Bt (18, 44, 58, 59, lOla, 108). To delay or reverse resistance to Bt in pests, we must first understand

981 citations