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Patel A, Miles A, Strackhouse T, Cook L, Leng S, Patel S, Klinger K, Rudrabhatla S, Potlakayala SD. Methods of crop improvement and applications towards fortifying food security. Front Genome Ed 2023; 5:1171969. [PMID: 37484652 PMCID: PMC10361821 DOI: 10.3389/fgeed.2023.1171969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 06/12/2023] [Indexed: 07/25/2023] Open
Abstract
Agriculture has supported human life from the beginning of civilization, despite a plethora of biotic (pests, pathogens) and abiotic (drought, cold) stressors being exerted on the global food demand. In the past 50 years, the enhanced understanding of cellular and molecular mechanisms in plants has led to novel innovations in biotechnology, resulting in the introduction of desired genes/traits through plant genetic engineering. Targeted genome editing technologies such as Zinc-Finger Nucleases (ZFNs), Transcription Activator-Like Effector Nucleases (TALENs), and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) have emerged as powerful tools for crop improvement. This new CRISPR technology is proving to be an efficient and straightforward process with low cost. It possesses applicability across most plant species, targets multiple genes, and is being used to engineer plant metabolic pathways to create resistance to pathogens and abiotic stressors. These novel genome editing (GE) technologies are poised to meet the UN's sustainable development goals of "zero hunger" and "good human health and wellbeing." These technologies could be more efficient in developing transgenic crops and aid in speeding up the regulatory approvals and risk assessments conducted by the US Departments of Agriculture (USDA), Food and Drug Administration (FDA), and Environmental Protection Agency (EPA).
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Affiliation(s)
- Aayushi Patel
- Penn State Harrisburg, Middletown, PA, United States
| | - Andrew Miles
- Penn State University Park, State College, University Park, PA, United States
| | | | - Logan Cook
- Penn State Harrisburg, Middletown, PA, United States
| | - Sining Leng
- Shanghai United Cell Biotechnology Co Ltd, Shanghai, China
| | - Shrina Patel
- Penn State Harrisburg, Middletown, PA, United States
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Kumar K, Gambhir G, Dass A, Tripathi AK, Singh A, Jha AK, Yadava P, Choudhary M, Rakshit S. Genetically modified crops: current status and future prospects. PLANTA 2020; 251:91. [PMID: 32236850 DOI: 10.1007/s00425-020-03372-8] [Citation(s) in RCA: 117] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Accepted: 02/28/2020] [Indexed: 05/20/2023]
Abstract
While transgenic technology has heralded a new era in crop improvement, several concerns have precluded their widespread acceptance. Alternative technologies, such as cisgenesis and genome-editing may address many of such issues and facilitate the development of genetically engineered crop varieties with multiple favourable traits. Genetic engineering and plant transformation have played a pivotal role in crop improvement via introducing beneficial foreign gene(s) or silencing the expression of endogenous gene(s) in crop plants. Genetically modified crops possess one or more useful traits, such as, herbicide tolerance, insect resistance, abiotic stress tolerance, disease resistance, and nutritional improvement. To date, nearly 525 different transgenic events in 32 crops have been approved for cultivation in different parts of the world. The adoption of transgenic technology has been shown to increase crop yields, reduce pesticide and insecticide use, reduce CO2 emissions, and decrease the cost of crop production. However, widespread adoption of transgenic crops carrying foreign genes faces roadblocks due to concerns of potential toxicity and allergenicity to human beings, potential environmental risks, such as chances of gene flow, adverse effects on non-target organisms, evolution of resistance in weeds and insects etc. These concerns have prompted the adoption of alternative technologies like cisgenesis, intragenesis, and most recently, genome editing. Some of these alternative technologies can be utilized to develop crop plants that are free from any foreign gene hence, it is expected that such crops might achieve higher consumer acceptance as compared to the transgenic crops and would get faster regulatory approvals. In this review, we present a comprehensive update on the current status of the genetically modified (GM) crops under cultivation. We also discuss the issues affecting widespread adoption of transgenic GM crops and comment upon the recent tools and techniques developed to address some of these concerns.
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Affiliation(s)
- Krishan Kumar
- ICAR-Indian Institute of Maize Research, Pusa Campus, New Delhi, 110012, India.
| | - Geetika Gambhir
- ICAR-Indian Institute of Maize Research, Pusa Campus, New Delhi, 110012, India
| | - Abhishek Dass
- ICAR-Indian Institute of Maize Research, Pusa Campus, New Delhi, 110012, India
| | - Amit Kumar Tripathi
- National Institute for Research in Environmental Health, Bhopal, 462001, India
| | - Alla Singh
- ICAR-Indian Institute of Maize Research, PAU Campus, Ludhiana, 141004, India
| | - Abhishek Kumar Jha
- ICAR-Indian Institute of Maize Research, Pusa Campus, New Delhi, 110012, India
| | - Pranjal Yadava
- ICAR-Indian Institute of Maize Research, Pusa Campus, New Delhi, 110012, India
| | - Mukesh Choudhary
- ICAR-Indian Institute of Maize Research, PAU Campus, Ludhiana, 141004, India
| | - Sujay Rakshit
- ICAR-Indian Institute of Maize Research, PAU Campus, Ludhiana, 141004, India
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Wang K, Shu C, Zhang J. Effective bacterial insecticidal proteins against coleopteran pests: A review. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2019; 102:e21558. [PMID: 31094011 DOI: 10.1002/arch.21558] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 04/02/2019] [Accepted: 04/17/2019] [Indexed: 06/09/2023]
Abstract
Coleoptera, the order of insects commonly referred to as beetles, are able to survive in various environments, and thus, comprise the largest order in the animal kingdom. Coleopterans mainly include coprophagous and phytophagous lineages, and many species of the latter lineage are serious pests. In addition to traditional chemical methods, biocontrol measures using various bacterial insecticidal proteins have also gradually been developed to control these insect pests. In this review, we summarized the possible coleopteran-pest-specific bacteria and insecticidal proteins that have been reported in the literature thus far and have provided a comprehensive overview and long-term guidance for the control of coleopteran pests in the future.
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Affiliation(s)
- Kui Wang
- College of Life Sciences, Northeast Agricultural University, Harbin, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Changlong Shu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jie Zhang
- College of Life Sciences, Northeast Agricultural University, Harbin, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Complete genome sequence of Bacillus thuringiensis tenebrionis 4AA1, a typical strain with toxicity to Coleopteran insects. J Biotechnol 2015; 204:15-6. [DOI: 10.1016/j.jbiotec.2015.03.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 03/17/2015] [Indexed: 11/21/2022]
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Li H, Liu R, Shu C, Zhang Q, Zhao S, Shao G, Zhang X, Gao J. Characterization of one novel cry8 gene from Bacillus thuringiensis strain Q52-7. World J Microbiol Biotechnol 2014; 30:3075-80. [PMID: 25218711 DOI: 10.1007/s11274-014-1734-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 08/31/2014] [Indexed: 11/30/2022]
Abstract
Bacillus thuringiensis (Bt) is the most widely used insecticidal microbe due to its specific toxicity and safe use with respect to animals and the environment. In this study, we isolated Bt strain Q52-7 from a soil sample collected in the Qian Shan District, Liao Ning Province, China. We observed that the Q52-7 strain produced spherical crystals. The Bt Q52-7 strain had high toxicity against Asian Cockchafer (Holotrichia parallela), exhibiting an LC50 of 3.80 × 10(9) cfu/g, but is not toxic for Anomala corpulenta Motschulsky and Holotrichia oblita. Using general cry8 primers, we amplified a 1.3 kb fragment with the polymerase chain reaction. Specific primers were designed for the amplified fragment to clone the full-length coding region. A novel gene, cry8Na1, had 69 % sequence similarity with cry8Ca1. cry8Na1 gene was successfully expressed in the HD-73(-) acrystalliferous mutant of Bt subsp. Kurstaki HD-73. Bioassays demonstrated that the Cry8Na1 protein is highly toxic for the H. parallela, with a 50 % lethal concentration of 8.18 × 10(10) colony forming units per gram.
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Affiliation(s)
- Haitao Li
- Northeast Agricultural University, Harbin, 150030, People's Republic of China
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Milutinović B, Stolpe C, Peuβ R, Armitage SAO, Kurtz J. The red flour beetle as a model for bacterial oral infections. PLoS One 2013; 8:e64638. [PMID: 23737991 PMCID: PMC3667772 DOI: 10.1371/journal.pone.0064638] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 04/17/2013] [Indexed: 01/03/2023] Open
Abstract
Experimental infection systems are important for studying antagonistic interactions and coevolution between hosts and their pathogens. The red flour beetle Tribolium castaneum and the spore-forming bacterial insect pathogen Bacillus thuringiensis (Bt) are widely used and tractable model organisms. However, they have not been employed yet as an efficient experimental system to study host-pathogen interactions. We used a high throughput oral infection protocol to infect T. castaneum insects with coleopteran specific B. thuringiensis bv. tenebrionis (Btt) bacteria. We found that larval mortality depends on the dietary spore concentration and on the duration of exposure to the spores. Furthermore, differential susceptibility of larvae from different T. castaneum populations indicates that the host genetic background influences infection success. The recovery of high numbers of infectious spores from the cadavers indicates successful replication of bacteria in the host and suggests that Btt could establish infectious cycles in T. castaneum in nature. We were able to transfer plasmids from Btt to a non-pathogenic but genetically well-characterised Bt strain, which was thereafter able to successfully infect T. castaneum, suggesting that factors residing on the plasmids are important for the virulence of Btt. The availability of a genetically accessible strain will provide an ideal model for more in-depth analyses of pathogenicity factors during oral infections. Combined with the availability of the full genome sequence of T. castaneum, this system will enable analyses of host responses during infection, as well as addressing basic questions concerning host-parasite coevolution.
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Affiliation(s)
- Barbara Milutinović
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Clemens Stolpe
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | - Robert Peuβ
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
| | | | - Joachim Kurtz
- Institute for Evolution and Biodiversity, University of Münster, Münster, Germany
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Mahadeva Swamy HM, Asokan R, Thimmegowda GG, Mahmood R. Expression of cry3A gene and its toxicity against Asian Gray Weevil Myllocerus undecimpustulatus undatus Marshall (Coleoptera: Curculionidae). J Basic Microbiol 2013; 53:664-76. [PMID: 23456617 DOI: 10.1002/jobm.201200272] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/10/2012] [Indexed: 11/10/2022]
Abstract
Coleopterans are the most damaging pests of many agricultural and forestry crops; there is an urgent need to develop effective biopesticides against these insects. Enhancers of Bt toxicity typify an opportunity to improve currently available commercial products into more effective control agents against diverse pests. A 1.9 kb DNA fragment, PCR amplified from native isolates of Bt using cry3A gene specific primers was cloned in expression vector pQE-80L and then used for transformation of Escherichia coli M15 cells. The sequence of the cloned crystal protein gene showed almost complete homology with a Coleopteran active Cry3A toxin gene with 117 mutations scattered in different domain regions encoding a protein of 645 amino acid residues in length, with a predicted molecular mass of 77.4 kDa. Phylogenetic analysis could be compulsive for new/novel Bacillus thuringiensis strains, allowing them to be grouped with related Cry proteins. The toxicity of Bt protein was determined against Myllocerus undecimpustulatus undatus Marshall (Coleoptera: Curculionidae) LC50 152 ng cm(-2). Genes coding for Coleopteran active Cry3A proteins have been isolated and their efficient expression will provide the tools necessary to increase the efficacy of Cry-based biopesticide against economically important beetles.
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Affiliation(s)
- H M Mahadeva Swamy
- Bio-Pesticide Laboratory (BPL), Division of Biotechnology, Indian Institute of Horticultural Research (IIHR), Hessaraghatta Lake Post, Bangalore, Karnataka, India.
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Expression of Bt-Cry3A in transgenic Populus alba × P. glandulosa and its effects on target and non-target pests and the arthropod community. Transgenic Res 2010; 20:523-32. [PMID: 20703808 DOI: 10.1007/s11248-010-9434-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Accepted: 07/27/2010] [Indexed: 10/19/2022]
Abstract
During the growing seasons of 2006-2008, feeding tests and field studies were conducted in Beijing, China, to investigate the effects of transgenic Bacillus thuringiensis (Bt) poplar (BGA-5) expressing the Cry3A protein (0.0264-0.0326% of the total soluble protein) on target and non-target pests and the arthropod community. The effects of BGA-5 on the target pest Plagiodera versicolora (Coleoptera, Chrysomelidae) and a non-target pest Clostera anachoreta (Lepidoptera, Notodontidae), were assessed under laboratory conditions. Total mortality of P. versicolora larvae fed with BGA-5 leaves was significantly higher than that of the control (P < 0.05). The exuviation index of P. versicolora larvae fed with BGA-5 tended to be higher than that of CK, but it was not significantly different. The pupation rate and eclosion rate of the survived larvae fed with BGA-5 were lower than that of CK, but it was also not significantly different. Additionally, no significant differences were detected in the mortality, exuviations index, pupation rate, or eclosion rate of C. anachoreta fed with leaves of transgenic and non-transgenic poplars. Furthermore, the arthropod communities in the Bt poplar and CK field stands were similar, as indicated by four diversity indices (Berge-Parker index, Shannon-Wiener indices, evenness index, and Simpson's inverted index) and the Bray-Curtis index. Therefore, the Bt-Cry3A poplar decreased damage by the target pest (P. versicolora), had no effects on a non-target pest (C. anachoreta), and generally did not have any significant negative effect on the poplar arthropod community.
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9
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Molecular and biological characterization of native Bacillus thuringiensis strains for controlling tomato leafminer (Tuta absoluta Meyrick) (Lepidoptera: Gelechiidae) in Colombia. World J Microbiol Biotechnol 2010. [DOI: 10.1007/s11274-010-0493-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Cry1B and Cry3A are active against Hypothenemus hampei Ferrari (Coleoptera: Scolytidae). J Invertebr Pathol 2009; 101:242-5. [PMID: 19465024 DOI: 10.1016/j.jip.2009.05.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2008] [Revised: 05/07/2009] [Accepted: 05/17/2009] [Indexed: 10/20/2022]
Abstract
Cry1B and Cry3 proteins from Bacillus thuringiensis are toxic to beetles such as the colorado potato beetle and the cottonwood leaf beetle. We report the development of a suitable rearing, bioassay method and the toxicity of these Cry proteins to coffee berry borer first instar larvae.
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11
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Haffani YZ, Cloutier C, Belzile FJ. Bacillus thuringiensis cry3Ca1 protein is toxic to the Colorado potato beetle, Leptinotarsa decemlineata (Say). Biotechnol Prog 2001; 17:211-6. [PMID: 11312696 DOI: 10.1021/bp000150d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We expressed the wild-type cry3Aa3 and cry3Ca1 Bacillus thuringiensis genes, which code for insecticidal proteins, in an Escherichia coli expression system. Highly purified preparations of the soluble delta-endotoxins were used to perform comparative bioassays with third-instar larvae of the Colorado potato beetle (CPB). Acute mortality data showed that Cry3Ca1 (LD(50) = 320.1 ng) was 2-fold more toxic than Cry3Aa3 (LD(50) = 672.9 ng). We also compared the chronic effects of sublethal doses of these toxins by measuring the consumption of untreated foliage and monitoring survival and development for 6 days after intoxication. No significant additional mortality was recorded, but we found that surviving larvae fed Cry3Ca1 consumed foliage at a slower rate than the larvae fed Cry3Aa3, suggesting more damage to their digestive epithelium. This study, the first assessment of the toxicity of cry3Ca1 in third-instar CPB, suggests cry3Ca1 will prove useful for the control of this important insect pest.
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Affiliation(s)
- Y Z Haffani
- Département de Phytologie, Pavillon C. E. Marchand, and Département de Biologie, Pavillon Vachon, Université Laval, Sainte-Foy, Québec G1K 7P4, Canada
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12
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Thomas PE, Lawson EC, Zalewski JC, Reed GL, Kaniewski WK. Extreme resistance to Potato leafroll virus in potato cv. Russet Burbank mediated by the viral replicase gene. Virus Res 2000; 71:49-62. [PMID: 11137161 DOI: 10.1016/s0168-1702(00)00187-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High levels of field resistance to Potato leafroll virus (PLRV; Genus: Polerovirus; Family: Luteoviridae) were achieved by expression of the unmodified, full-length PLRV replicase gene in potato plants cv. Russet Burbank. A high degree of resistance was also achieved, but less frequently, by expression of a truncated construct of the replicase gene. In limited testing, neither miss-frame nor antisense constructs of the replicase gene conferred resistance. The degree of resistance expressed among different transformant lines ranged from near immunity to full susceptibility. Resistance to the Colorado potato beetle (Leptinotarsa decemlineata Say) was combined with resistance to PLRV by expression of the cry3A insect control protein gene from Bacillus thuringiensis var. tenebrionis in combination with the unmodified, full-length, viral replicase gene. Resistance was expressed as a reduced incidence of infection detectable by foliage symptoms or serological tests. Reduced incidence of infection was not associated with a decrease in virus antigen concentration in the few plants of resistant lines that became infected. Virus was not detected in the foliage of symptomless plants but was detected in progeny plants produced from the tubers of inoculated but symptomless test plants of some resistant lines. The resistance was effective under natural exposure and against plant-to-plant spread of PLRV by the aphid vector, Myzus persicae Sulzer. Three of the resistant lines selected in these studies were released and are now in commercial production.
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Affiliation(s)
- P E Thomas
- Vegetable and Forage Crop Production, Agricultural Research Service, US Department of Agriculture, 24106 N. Bunn Road, Prosser, WA 99350-9687, USA.
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Güereca L, Bravo A. The oligomeric state of Bacillus thuringiensis Cry toxins in solution. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1429:342-50. [PMID: 9989219 DOI: 10.1016/s0167-4838(98)00241-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The molecular mass of different Cry toxins produced by Bacillus thuringiensis bacteria was estimated by size-exclusion chromatography and non-denaturing polyacrylamide gel electrophoresis at neutral and alkaline pH in order to assess the existence of oligomers in solution. We found that Cry1Aa, Cry1Ac, Cry1C, Cry1D and Cry3A toxins exist in solution as a mixture of monomer and high molecular mass aggregates with an apparent molecular mass greater than 600 kDa, that depend on the time elapsed between toxin activation and analysis. Aggregation of toxins by disulfide bonds is unlikely because aggregates are also observed in samples incubated with DTT. These data show that the Cry toxins studied do not form oligomers of less than ten subunits in solution and suggest that oligomer formation may occur after the toxin binds to the receptor and inserts into the membrane.
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Affiliation(s)
- L Güereca
- Departamento de Microbiología, Instituto de Biotecnología/UNAM, Morelos, Mexico
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Orduz S, Realpe M, Arango R, Murillo LA, Delécluse A. Sequence of the cry11Bb11 gene from Bacillus thuringiensis subsp. medellin and toxicity analysis of its encoded protein. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1388:267-72. [PMID: 9774743 DOI: 10.1016/s0167-4838(98)00168-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The nucleotide sequence of the cry11Bb1 gene from Bacillus thuringiensis subsp. medellin was determined. The corresponding protein has a deduced molecular mass of 88.2 kDa, and is 60.9% and 83% identical to the proteins Cry11Aa1 and Cry11Ba1, respectively. The Cry11Bb1 protein contains five repetitive blocks of 16 amino acids at the C terminal part. It is highly toxic to first instar laboratory reared Aedes aegypti, Anopheles albimanus and Culex quinquefasciatus larvae.
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Affiliation(s)
- S Orduz
- Unidad de Biotecnología y Control Biológico, Corporación para Investigaciones Biológicas, Apartado Aéreo 7378, Medellín, Colombia
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Carroll J, Convents D, Van Damme J, Boets A, Van Rie J, Ellar DJ. Intramolecular proteolytic cleavage of Bacillus thuringiensis Cry3A delta-endotoxin may facilitate its coleopteran toxicity. J Invertebr Pathol 1997; 70:41-9. [PMID: 9217464 DOI: 10.1006/jipa.1997.4656] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The Cry3A delta-endotoxin protein inclusion synthesized by Bacillus thuringiensis subsp. tenebrionis is soluble in alkaline and acid buffer solutions but the toxin precipitates when returned to neutral pH conditions. The midgut pH of susceptible beetle larvae is neutral to slightly acidic, a pH environment in which the Cry3A toxin is insoluble. To investigate this paradox we studied the Cry3A toxin after various proteolytic treatments. In many cases the toxin was cleaved into polypeptides that remained associated under non-denaturing conditions. Interestingly a chymotrypsinized Cry3A product was soluble under neutral pH conditions, retained full activity against susceptible beetle larvae, and exhibited specific binding to Leptinotarsa decemlineata midgut membranes.
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Affiliation(s)
- J Carroll
- Department of Biochemistry, University of Cambridge, United Kingdom
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17
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Genetic transformation of the ectomycorrhizal fungus Paxillus involutus by particle bombardment. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/s0953-7562(09)80713-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Adams LF, Mathewes S, O'Hara P, Petersen A, Gürtler H. Elucidation of the mechanism of CryIIIA overproduction in a mutagenized strain of Bacillus thuringiensis var. tenebrionis. Mol Microbiol 1994; 14:381-9. [PMID: 7830581 DOI: 10.1111/j.1365-2958.1994.tb01298.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
NB176 is a Bacillus thuringiensis mutant derived by gamma-irradiation of NB125 Bacillus thuringiensis var. tenebrionis (Krieg). It exhibits two interesting phenotypes: (i) oligosporogeny and (ii) twofold to threefold overproduction of the CryIIIA protein. Southern profiles of the NB176 strain showed an additional copy(s) of the cryIIIA gene located on a 4 kb HindIII fragment, in addition to the expected cryIIIA gene on a 3 kb HindIII fragment. Each cryIIIA gene-bearing HindIII fragment was cloned from NB176. The restriction map of the 3 kb HindIII fragment was identical to that published by Donovan and coworkers. Sequencing of the 4 kb HindIII fragment showed no alterations in the promoter region of the cryIIIA gene but did show replacement of the region immediately following the cryIIIA open reading frame with a sequence encoding a transposase with 50% amino acid homology to that of Tn1000. These findings suggest that the overproduction phenotype of NB176 results from extra copies of the cryIIIA gene produced from a transposition event(s) induced or stabilized by gamma-irradiation. Integration of additional copies of the cryIIIA gene into the native 90 MDa plasmid of the wild-type B. thuringiensis var. tenebrionis strain resulted in strains that made enormous crystals, many possessing greatly enhanced insecticidal activity.
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Affiliation(s)
- L F Adams
- Novo Nordisk Biotech, Inc., Davis, California 95616
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Hori H, Suzuki N, Ogiwara K, Himejima M, Indrasith LS, Minami M, Asano S, Sato R, Ohba M, Iwahana H. Characterization of larvicidal toxin protein from Bacillus thuringiensis serovar japonensis strain Buibui specific for scarabaeid beetles. THE JOURNAL OF APPLIED BACTERIOLOGY 1994; 76:307-13. [PMID: 8200856 DOI: 10.1111/j.1365-2672.1994.tb01633.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The delta-endo toxin proteins from Bacillus thuringiensis which kill the larvae of various scarabaeid beetles such as Anomala cuprea, A. rufocuprea and Popillia japonica were purified by DEAE ion exchange chromatography. A protein with a molecular size of 130 kDa was purified. During the purification a minor peak was also detected which was estimated to be 67 kDa by SDS-PAGE. Both 130 and 67 kDa proteins showed larvicidal activity against A. cuprea. The lethal concentration of the 130 kDa protein which killed 50% of the larvae tested (LC50) against A. cuprea was 2 micrograms g-1 compost. A comparison by SDS-PAGE of the V8 protease digestion pattern of the 130 and 67 kDa larvicidal proteins showed that proteolytic resistant core peptides of approximately 60 kDa molecular size were resulted. The N-terminus amino acid sequence of the 130 and 67 kDa proteins was determined to be NH2-XXPNNQNEYEIIDAL and NH2-XSRNPGTFI, respectively, which is not identical to the sequence of CryIA, CryIB, CryIC and CryIII proteins.
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Affiliation(s)
- H Hori
- Tsukuba Laboratories for Research and Development, Kubota Corp., Ibaraki, Japan
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Sutton DW, Havstad PK, Kemp JD. Synthetic cryIIIA gene from Bacillus thuringiensis improved for high expression in plants. Transgenic Res 1992; 1:228-36. [PMID: 1301214 DOI: 10.1007/bf02524753] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A 1974 bp synthetic gene was constructed from chemically synthesized oligonucleotides in order to improve transgenic protein expression of the cryIIIA gene from Bacillus thuringiensis var. tenebrionis in transgenic tobacco. The crystal toxin genes (cry) from B. thuringiensis are difficult to express in plants even when under the control of efficient plant regulatory sequences. We identified and eliminated five classes of sequence found throughout the cryIIIA gene that mimic eukaryotic processing signals and which may be responsible for the low levels of transcription and translation. Furthermore, the GC content of the gene was raised from 36% to 49% and the codon usage was changed to be more plant-like. When the synthetic gene was placed behind the cauliflower mosaic virus 35S promoter and the alfalfa mosaic virus translational enhancer, up to 0.6% of the total protein in transgenic tobacco plants was cryIIIA as measured from immunoblot analysis. Bioassay data using potato beetle larvae confirmed this estimate.
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MESH Headings
- Animals
- Bacillus thuringiensis/genetics
- Bacillus thuringiensis Toxins
- Bacterial Proteins/biosynthesis
- Bacterial Proteins/genetics
- Bacterial Proteins/toxicity
- Bacterial Toxins/genetics
- Base Sequence
- Biological Assay
- Blotting, Northern
- Cloning, Molecular/methods
- Coleoptera/drug effects
- Endotoxins
- Escherichia coli/genetics
- Genes, Bacterial
- Genes, Synthetic
- Hemolysin Proteins
- Larva
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Plants, Genetically Modified
- Plants, Toxic
- RNA, Messenger/biosynthesis
- RNA, Messenger/isolation & purification
- Restriction Mapping
- Nicotiana/genetics
- Transcription, Genetic
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Affiliation(s)
- D W Sutton
- Plant Genetic Engineering Laboratory, New Mexico State University, Las Cruces 88003
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21
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Koller CN, Bauer LS, Hollingworth RM. Characterization of the pH-mediated solubility of Bacillus thuringiensis var. san diego native delta-endotoxin crystals. Biochem Biophys Res Commun 1992; 184:692-9. [PMID: 1315528 DOI: 10.1016/0006-291x(92)90645-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Native crystals of Bacillus thuringiensis var. san diego, a coleopteran-specific delta-endotoxin, were metabolically labelled with [35S]methionine. Specific activity was 82,000 CPM/micrograms (2.44 Ci/mmol). Using a universal buffer formulated with the same ionic strength at every pH, we determined that native crystals dissolve above pH 10 and below pH 4. At the acidic pH, the rate of solubilization was substantially slower than at the alkaline pH. Recrystallization rates for the toxin were similar regardless of solubilization conditions. The banding patterns in denatured polyacrylamide gel electrophoresis were unaffected by solubilization conditions. Toxicity was higher for soluble toxin compared to crystal toxin, but virtually identical for the acidic and alkaline produced solutions. Acid solubilization is significant because of the acidic midgut of susceptible Coleoptera.
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Affiliation(s)
- C N Koller
- Pesticide Research Center, Michigan State University, E. Lansing 48824
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22
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Starkey MP, Fenning T, Davey MR, Mulligan BJ. Design and use of synthetic oligonucleotide probes in the cloning of delta-endotoxin genes from Bacillus thuringiensis. Enzyme Microb Technol 1991; 13:661-4. [PMID: 1369333 DOI: 10.1016/0141-0229(91)90081-k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A detailed protocol is described for the design and use of synthetic oligonucleotide probes for screening DNA libraries from Bacillus thuringiensis var. kurstaki (strain HD191) for copies of the gene (tox) encoding the insecticidal delta-endotoxin. Two homologous tox genes were identified in this organism; one of these was located on a 75-kb plasmid and the other on a second large plasmid or the bacterial chromosome. A tox gene was isolated as a 6.5-kb HindIII fragment of B. thuringiensis plasmid DNA.
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Affiliation(s)
- M P Starkey
- Department of Botany, University of Nottingham, University Park, UK
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23
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MacIntosh SC, Stone TB, Sims SR, Hunst PL, Greenplate JT, Marrone PG, Perlak FJ, Fischhoff DA, Fuchs RL. Specificity and efficacy of purified Bacillus thuringiensis proteins against agronomically important insects. J Invertebr Pathol 1990; 56:258-66. [PMID: 2273290 DOI: 10.1016/0022-2011(90)90109-j] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The host range and relative efficacy of three purified Bacillus thuringiensis insect control proteins were determined against 17 different agronomically important insects representing five orders and one species of mite. The three B. thuringiensis proteins were single gene products from B. thuringiensis ssp. kurstaki HD-1 (CryIA(b)) and HD-73 (CryIA(c)), both lepidopteran-specific proteins, and B. thuringiensis ssp. tenebrionis (CryIIIA), a coleopteran-specific protein. Seven insects showed sensitivity to both B. thuringiensis ssp. kurstaki proteins, whereas only 1 of the 18 insects was sensitive to B. thuringiensis ssp. tenebrionis protein. The level of B. thuringiensis ssp. kurstaki protein required for 50% mortality (LC50) varied by 2000-fold for these 7 insects. A larval growth inhibition assay was developed to determine the amount of B. thuringiensis ssp. kurstaki protein required to inhibit larval growth by 50% (EC50). This extremely sensitive assay enabled detection of B. thuringiensis ssp. kurstaki HD-73 levels as low as 1 ng/ml.
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Affiliation(s)
- S C MacIntosh
- Plant Science Technology, Monsanto Agricultural Company, St. Louis, Missouri 63198
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24
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MacIntosh SC, McPherson SL, Perlak FJ, Marrone PG, Fuchs RL. Purification and characterization of Bacillus thuringiensis var. tenebrionis insecticidal proteins produced in E. coli. Biochem Biophys Res Commun 1990; 170:665-72. [PMID: 2116794 DOI: 10.1016/0006-291x(90)92143-n] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Native and single amino acid variants of the Bacillus thuringiensis var. tenebrionis insecticidal proteins were expressed in Escherichia coli, purified and examined for biological and biochemical properties. A novel, pH dependent, preferential precipitation method was implemented to purify Escherichia coli produced Bacillus thuringiensis var. tenebrionis proteins, which are active against Colorado potato beetle (Leptinotarsa decemlineata) larvae. Cysteine residues of the native Bacillus thuringiensis var. tenebrionis protein were replaced by serine residues by site-directed mutagenesis to investigate the biological and structural importance of the individual cysteine residues. Sulfhydryl determination of the native and amino acid variant Bacillus thuringiensis var. tenebrionis proteins revealed that the native protein contains no disulfide bonds. Modification of the carboxyl terminal cysteine residue (amino acid 540) caused complete inactivation of the protein. Native, truncated and single amino acid variants (other than at amino acid 540) exhibited insecticidal activities comparable to each other and to solubilized crystals from the original strain.
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Affiliation(s)
- S C MacIntosh
- Monsanto Agricultural Company, Saint Louis, Missouri 63198
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26
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Sanchis V, Lereclus D, Menou G, Chaufaux J, Guo S, Lecadet MM. Nucleotide sequence and analysis of the N-terminal coding region of the Spodoptera-active delta-endotoxin gene of Bacillus thuringiensis aizawai 7.29. Mol Microbiol 1989; 3:229-38. [PMID: 2548060 DOI: 10.1111/j.1365-2958.1989.tb01812.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The nucleotide sequence of a 2711bp DNA segment which contains the N-terminal coding sequence and the 5' flanking region of a crystal protein gene (bta) from Bacillus thuringiensis subsp. aizawai 7.29 has been determined. The coding region encodes an 824 amino-acid polypeptide corresponding to a carboxy-terminally truncated delta-endotoxin specifically active against the cotton leaf worm Spodoptera littoralis. Comparison of the deduced amino acid sequence of the bta gene with that of the 4.5, 5.3 and 6.6 kb classes of lepidopteran-active delta-endotoxins revealed that the Bta sequence contains a very high level of amino acid substitutions in the N-terminal part of the protoxin molecule. The substitutions are grouped in several highly variable segments separated by highly conserved regions. These conserved domains are also present in the dipteran- and coleopteran-active delta-endotoxins. The control region of the bta gene shows considerable DNA identity with the control regions of the other lepidopteran-active genes. Deletions of the 3' region of the gene were carried out and the toxic fraction of the bta delta-endotoxin was identified with the N-terminal half of the molecule.
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Affiliation(s)
- V Sanchis
- Unité de Biochimie Microbienne, Institut Pasteur, Paris, France
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27
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Brousseau R, Masson L. Bacillus thuringiensis insecticidal crystal toxins: Gene structure and mode of action. Biotechnol Adv 1988; 6:697-724. [PMID: 14550036 DOI: 10.1016/0734-9750(88)91920-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Thanks to the techniques of recombinant DNA, there is now abundant sequence information on several endotoxin genes of Bacillus thuringiensis. The task of correlating this sequence information with the economically important aspects of the toxins such as insect specificity, LD(50) and speed of kill is now under worldwide investigation. Progress has also been made on understanding the mechanism of action of the toxins and on identifying the parts of the protoxin which are important in toxicity. Taken together, the mechanistic data and the sequence information allow the first attempts at rational design of mutant endotoxin genes and greatly facilitate the transfer of those genes to other organisms such as plants. More information is still needed, however, as to the nature of the binding site of the toxin and on the three-dimensional structure of the activated toxins.
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Affiliation(s)
- R Brousseau
- Biotechnology Research Institute, Montreal, Quebec, Canada
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