Hostname: page-component-84b7d79bbc-5lx2p Total loading time: 0 Render date: 2024-07-26T07:21:15.943Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  16 April 2015

H. M. N. CHEEMA*
Affiliation:
Plant Genetic Resources Lab, Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan
A. A. KHAN
Affiliation:
Plant Genetic Resources Lab, Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan
M. I. KHAN
Affiliation:
Plant Genetic Resources Lab, Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan
U. ASLAM
Affiliation:
Plant Genetic Resources Lab, Department of Plant Breeding and Genetics, University of Agriculture, Faisalabad, Pakistan
I. A. RANA
Affiliation:
Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Pakistan
I. A. KHAN
Affiliation:
Centre of Agricultural Biochemistry and Biotechnology, University of Agriculture, Faisalabad, Pakistan
*
*To whom all correspondence should be addressed. Email: masooma@uaf.edu.pk

Summary

Genetically 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.

Type
Crops and Soils Research Papers
Copyright
Copyright © Cambridge University Press 2015 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Abel, C. A. & Adamczyk, J. J. Jr (2004). Relative concentration of Cry1A in maize leaves and cotton bolls with diverse chlorophyll content and corresponding larval development of fall armyworm (Lepidoptera: Noctuidae) and southwestern corn borer (Lepidoptera: Crambidae) on maize whorl leaf profiles. Journal of Economic Entomology 97, 17371744.CrossRefGoogle ScholarPubMed
Adamczyk, J. J. Jr & Meredith, W. (2004). Genetic basis for variability of Cry1Ac expression among commercial transgenic Bacillus thuringiensis (Bt) cotton cultivars in the United States. Journal of Cotton Science 8, 1723.Google Scholar
Adamczyk, J. J. Jr & Sumerford, D. V. (2001). Potential factors impacting season-long expression of Cry1Ac in 13 commercial varieties of Bollgard® cotton. Journal of Insect Science 1, 13. PMCID: 355897.CrossRefGoogle ScholarPubMed
Adamczyk, J. J. Jr, Perera, O. & Meredith, W. R. (2009). Production of mRNA from the cry1Ac transgene differs among Bollgard® lines which correlates to the level of subsequent protein. Transgenic Research 18, 143149.CrossRefGoogle Scholar
Aguilera, M., Querci, M., Pastor, S., Bellocchi, G., Milcamps, A. & Van den Eede, G. (2009). Assessing copy number of MON 810 integrations in commercial seed maize varieties by 5′ event-specific real-time PCR validated method coupled to 2−ΔΔCT analysis. Food Analytical Methods 2, 7379.CrossRefGoogle Scholar
Ahsan, R. & Altaf, Z. (2009). Development, adoption and performance of Bt cotton in Pakistan: a review. Pakistan Journal of Agricultural Research (Pakistan) 22, 7385.Google Scholar
Ali, S., Hameed, S., Masood, S., Ali, G. M. & Zafar, Y. (2010). Status of Bt cotton cultivation in major growing areas of Pakistan. Pakistan Journal of Botany 42, 15831594.Google Scholar
Bakhsh, A., Rao, A. Q., Shahid, A. A., Husnain, T. & Riazuddin, S. (2009). Insect resistance and risk assessment studies in advance lines of Bt cotton harboring Cry1Ac and Cry2A genes. American-Eurasian Journal of Agricultural and Environmental Sciences 6, 111.Google Scholar
Bakhsh, A., Rao, A. Q., Shahid, A. A., Husnain, T. & Riazuddin, S. (2010). CaMV 35S is a developmental promoter being temporal and spatial in expression pattern of insecticidal genes (Cry1Ac & Cry2A) in cotton. Australian Journal of Basic and Applied Science 4, 3744.Google Scholar
Beltrán, J., Jaimes, H., Echeverry, M., Ladino, Y., López, D., Duque, M. C., Chavarriaga, P. & Tohme, J. (2009). Quantitative analysis of transgenes in cassava plants using real-time PCR technology. In Vitro Cellular and Developmental Biology – Plant 45, 4856.CrossRefGoogle Scholar
Clive, J. (2013). Global Status of Commercialized Biotech/GM Crops: 2013. ISAAA Brief 46. Manila, The Philippines: ISAAA.Google Scholar
Cororaton, C. B., Salam, A., Altaf, Z., Orden, D., Dewina, R., Minot, N. & Nazli, H. (2008). Cotton-textile-apparel Sectors of Pakistan: Situations and Challenges Faced. IFPRI Discussion Paper no. 800. Washington, DC: International Food Policy Research Institute.Google Scholar
Doyle, J. J. & Doyle, J. L. (1990). Isolation of plant DNA from fresh tissue. Focus 12, 1315.Google Scholar
Ferré, J. & Van Rie, J. (2002). Biochemistry and genetics of insect resistance to Bacillus thuringiensis. Annual Review of Entomology 47, 501533.CrossRefGoogle ScholarPubMed
Gaskell, G., Bauer, M. W., Durant, J. & Allum, N. C. (1999). Worlds apart? the reception of genetically modified foods in Europe and the US. Science 285, 384387.CrossRefGoogle Scholar
Gore, J., Leonard, B. R. & Adamczyk, J. J. (2001). Bollworm (Lepidoptera: Noctuidae) survival on ‘Bollgard’ and ‘Bollgard II’ cotton flower bud and flower components. Journal of Economic Entomology 94, 14451451.CrossRefGoogle ScholarPubMed
Greenplate, J. T., Penn, S. R., Mullins, J. W. & Oppenhuizen, M. (2000). Seasonal Cry1Ac levels in DP50B: the ‘Bollgard® basis’ for Bollgard II. In Proceedings of the Beltwide Cotton Conference (Eds Dugger, P. & Richter, R.), pp. 1039–1040.Google Scholar
Greenplate, J. T., Mullins, W., Penn, S. & Embry, K. (2001). Cry1Ac levels in candidate commercial Bollgard® varieties as influenced by environment, variety and plant age: 1999 gene equivalency field studies. In Proceedings of the Beltwide Cotton Conference (Eds Dugger, P. & Richter, R.), pp. 790–793. Memphis, TN, USA: National Cotton Council of America.Google Scholar
Guo, W. Z., Sun, J., Guo, Y. F. & Zhang, T. Z. (2001). Investigation of different dosages of inserted Bt genes and their insect-resistance in transgenic Bt cotton. Yi Chuan Xue Bao (Acta Genetica Sinica) 28, 668676.Google ScholarPubMed
Gutierrez, A. P., Adamczyk, J. J. Jr, Ponsard, S. & Ellis, C. K. (2006). Physiologically based demographics of Bt cotton–pest interactions: II. Temporal refuges, natural enemy interactions. Ecological Modelling 191, 360382.CrossRefGoogle Scholar
Holt, H. E., Mares, C. & Akhurst, R. (2002). Determination of the Cry Protein Content of Bt Transgenic Cotton : a Technical Manual for Laboratory Use. Canberra: CSIRO Australia, Division of Entomology.Google Scholar
Jackson, R. E., Bradley, J. R. Jr, Van Duyn, J. W. & Gould, F. (2004). Comparative production of Helicoverpa zea (Lepidoptera: Noctuidae) from transgenic cotton expressing either one or two Bacillus thuringiensis proteins with and without insecticide oversprays. Journal of Economic Entomology 97, 17191725.CrossRefGoogle ScholarPubMed
Khan, S. M., Saeed, I., Shah, M., Shah, S. F. & Mir, H. (2012). Integration of tolerance of Bt cotton varieties with insecticides against spotted bollworm, Earias insulana (Boisd.) and E. vittella (Fab.)(Noctuidae: Lepidoptera). Sarhad Journal of Agriculture 28, 5762.Google Scholar
Kranthi, K. R., Naidu, S., Dhawad, C. S., Tatwawadi, A., Mate, K., Patil, E., Bharose, A. A., Behere, G. T., Wadaskar, R. M. & Kranthi, S. (2005). Temporal and intra-plant variability of Cry1Ac expression in Bt-cotton and its influence on the survival of the cotton bollworm, Helicoverpa armigera (Hubner) (Noctuidae: Lepidoptera). Current Science 89, 291298.Google Scholar
Lee, S. H., Kang, S. H., Park, Y. H., Min, D. M. & Kim, Y. M. (2006 a). Quantitative analysis of two genetically modified maize lines by real-time PCR. Journal of Microbiology and Biotechnology 16, 205211.Google Scholar
Lee, S. H., Min, D. M. & Kim, J. K. (2006 b). Qualitative and quantitative polymerase chain reaction analysis for genetically modified maize MON863. Journal of Agricultural and Food Chemistry 54, 11241129.CrossRefGoogle ScholarPubMed
Lee, S. H., Kim, J. K. & Yi, B. Y. (2007). Detection methods for biotech cotton MON 15985 and MON 88913 by PCR. Journal of Agricultural and Food Chemistry 55, 33513357.CrossRefGoogle ScholarPubMed
Li, Z., Hansen, J. L., Liu, Y., Zemetra, R. S. & Berger, P. H. (2004). Using real-time PCR to determine transgene copy number in wheat. Plant Molecular Biology Reporter 22, 179188.CrossRefGoogle Scholar
Mahon, R., Finnegan, J., Olsen, K. & Lawrence, L. (2002). Environmental stress and the efficacy of Bt cotton. Australian Cottongrower 23, 1822.Google Scholar
Masood, A., Arif, M. J., Hamed, M. & Talpur, M. A. (2011). Field performance of Trichogramma chilonis against cotton bollworms infestation in different cotton varieties as a sustainable IPM approach. Pakistan Journal of Agriculture, Agricultural Engineering and Veterinary Science 27, 176184.Google Scholar
Olsen, K. M., Daly, J. C., Holt, H. E. & Finnegan, E. J. (2005). Season-long variation in expression of Cry1Ac gene and efficacy of Bacillus thuringiensis toxin in transgenic cotton against Helicoverpa armigera (Lepidoptera: Noctuidae). Journal of Economic Entomology 98, 10071017.CrossRefGoogle ScholarPubMed
Randhawa, G. J., Chhabra, R. & Singh, M. (2009). Multiplex PCR-based simultaneous amplification of selectable marker and reporter genes for the screening of genetically modified crops. Journal of Agricultural and Food Chemistry 57, 51675172.CrossRefGoogle ScholarPubMed
Randhawa, G. J., Chhabra, R. & Singh, M. (2010). Decaplex and real-time PCR based detection of MON531 and MON15985 Bt cotton events. Journal of Agricultural and Food Chemistry 58, 98759881.CrossRefGoogle ScholarPubMed
Singh, C. K., Ojha, A., Bhatanagar, R. K. & Kachru, D. N. (2008). Detection and characterization of recombinant DNA expressing vip3A-type insecticidal gene in GMOs standard single, multiplex and construct-specific PCR assays. Analytical and Bioanalytical Chemistry 390, 377387.CrossRefGoogle ScholarPubMed
Tariq, M. I., Afzal, S., Hussain, I. & Sultana, N. (2007). Pesticides exposure in Pakistan: a review. Environment International 33, 11071122.CrossRefGoogle ScholarPubMed
Wan, P., Zhang, Y., Wu, K. & Huang, M. (2005). Seasonal expression profiles of insecticidal protein and control efficacy against Helicoverpa armigera for Bt cotton in the Yangtze River valley of China. Journal of Economic Entomology 98, 195201.CrossRefGoogle ScholarPubMed
Wasti, S. E. (2013). Pakistan Economic Survey 2012–13. Islamabad, Pakistan: Ministry of Finance, Government of Pakistan.Google Scholar
Wu, Y., Wu, G., Xiao, L. & Lu, C. (2007). Event-specific qualitative and quantitative PCR detection methods for transgenic rapeseed hybrids MS1× RF1 and MS1× RF2. Journal of Agricultural and Food Chemistry 55, 83808389.CrossRefGoogle Scholar
Xia, L., Xu, Q. & Guo, S. (2004). Bt insecticidal gene and its temporal expression in transgenic cotton plants. Acta Agronomica Sinica 31, 197202.Google Scholar
Yang, L., Pan, A., Zhang, K., Guo, J., Yin, C., Chen, J., Huang, C. & Zhang, D. (2005 a). Identification and quantification of three genetically modified insect resistant cotton lines using conventional and TaqMan real-time polymerase chain reaction methods. Journal of Agricultural Food Chemistry 53, 62226229.CrossRefGoogle ScholarPubMed
Yang, L., Pan, A., Zhang, K., Yin, C., Qian, B., Chen, J., Huang, C. & Zhang, D. (2005 b). Qualitative and quantitative PCR methods for event-specific detection of genetically modified cotton Mon1445 and Mon531. Transgenic Research 14, 817831.CrossRefGoogle ScholarPubMed