Skip to main content

Advertisement

Log in

The variability of processes involved in transgene dispersal—case studies from Brassica and related genera

  • IMPLICATIONS OF GM-CROP CULTIVATION • SERIES • REVIEW ARTICLE
  • Published:
Environmental Science and Pollution Research Aims and scope Submit manuscript

Abstract

Background, aim, and scope

We strive to predict consequences of genetically modified plants (GMPs) being cultivated openly in the environment, as human and animal health, biodiversity, agricultural practise and farmers’ economy could be affected. Therefore, it is unfortunate that the risk assessment of GMPs is burdened by uncertainty. One of the reasons for the uncertainty is that the GMPs are interacting with the ecosystems at the release site thereby creating variability. This variability, e.g. in gene flow, makes consequence analysis difficult. The review illustrates the great uncertainty of results from gene-flow analysis.

Main features

Many independent experiments were performed on the individual processes in gene flow. The results comprise information both from laboratory, growth chambers and field trials, and they were generated using molecular or phenotypic markers and analysis of fitness parameters. Monitoring of the extent of spontaneous introgression in natural populations was also performed. Modelling was used as an additional tool to identify key parameters in gene flow.

Results

The GM plant may affect the environment directly or indirectly by dispersal of the transgene. Magnitude of the transgene dispersal will depend on the GM crop, the agricultural practise and the environment of the release site. From case-to-case these three factors provide a variability that is reflected in widely different likelihoods of transgene dispersal and fitness of introgressed plants. In the present review, this is illustrated through a bunch of examples mostly from our own research on oilseed rape, Brassica napus. In the Brassica cases, the variability affected all five main steps in the process of gene dispersal. The modelling performed suggests that in Brassica, differences in fitness among plant genome classes could be a dominant factor in the establishment and survival of introgressed populations.

Discussion

Up to now, experimental analyses have mainly focused on studying the many individual processes of gene flow. This can be criticised, as these experiments are normally carried out in widely different environments and with different genotypes, and thus providing bits and pieces difficult to assemble. Only few gene-flow studies have been performed in natural populations and over several plant generations, though this could give a more coherent and holistic view.

Conclusion

The variability inherent in the processes of gene flow in Brassica is apparent and remedies are wished for. One possibility is to expose the study species to additional experiments and monitoring, but this is costly and will likely not cover all possible scenarios. Another remedy is modelling gene flow. Modelling is a valuable tool in identifying key factors in the gene-flow process for which more knowledge is needed, and identifying parameters and processes which are relatively insensitive to change and therefore require less attention in future collections of data. But the interdependence between models and experimental data is extensive, as models depend on experimental data for their development or testing.

Recommendations

More and more transgenic varieties are being grown worldwide harbouring genes that might potentially affect the environment (e.g. drought tolerance, salt tolerance, disease tolerance, pharmaceutical genes). This calls for a thorough risk assessment. However, in Brassica, the limited and uncertain knowledge on gene flow is an obstacle to this. Modelling of gene flow should be optimised, and modelling outputs verified in targeted field studies and at the landscape level. Last but not least, it is important to remember that transgene flow in itself is not necessarily a thread, but it is the consequences of gene flow that may jeopardise the ecosystems and the agricultural production. This emphasises the importance of consequence analysis of genetically modified plants.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

References

  • Allainguillaume J, Alexander M, Bullock JM, Saunders M, Allender CJ, King G, Ford CS, Wilkinson MJ (2006) Fitness of hybrids between rapeseed (Brassica napus) and wild Brassica rapa in natural habitats. Molec Ecol 15:1175–1184

    Article  CAS  Google Scholar 

  • Ammitzbøll HA, Jørgensen RB (2006) Hybridization between oilseed rape (Brassica napus) and different populations and species of Raphanus. Environ Biosaf Res 5:3–13

    Article  Google Scholar 

  • Ammitzbøll HA, Mikkelsen T, Jørgensen RB (2005) Environmental effects of transgene expression on hybrid fitness—a case study on oilseed rape. Environ Biosaf Re 4:3–12

    Article  Google Scholar 

  • Andersen NS, Poulsen G, Andersen BA, Kiær LP, D’Hertefeldt T, Wilkinson MJ, Jørgensen RB (2009) Genetic variation in wild and cultivated Brassica rapa L. Genetic Resources and Crop Evolution 56:189–200

    Article  Google Scholar 

  • Beckie HJ, Hall LM (2008) Simple to complex: modelling crop pollen-mediated gene flow. Plant Sci 175:615–628

    Article  CAS  Google Scholar 

  • Chandler S, Dunwell JM (2008) Gene flow, risk assessment and the environmental release of transgenic plants. Crit Rev Plant Sci 27:25–49

    Article  CAS  Google Scholar 

  • Colbach N (2009) Effect of cropping systems on species dynamics and gene flow at the landscape level. A modelling approach. Environ Sci Pollut Res This volume, page X–XX

  • Colbach N, Durr C, Gruber S, Pekrun C (2008) Modelling the seed bank evolution and emergence of oilseed rape volunteers for managing co-existence of GM and non-GM varieties. Eur J Agron 28:19–32

    Article  CAS  Google Scholar 

  • D’Hertefeldt T, Jørgensen RB, Pettersson LB (2008) Long-term persistence of GM oilseed rape in the seedbank Biol Lett 4:314–317

    Google Scholar 

  • Ellstrand NC, Garner LC, Hegde S, Roberto G, Lesley B (2007) Spontaneous hybridization between maize and teosinte. J Heredity 98:183–187

    Article  CAS  Google Scholar 

  • Fenart S, Austerlitz F, Cuguen J, Arnaud JF (2007) Long distance pollen-mediated gene flow at a landscape level: the weed beet as a case study. Mol Ecol 16:3801–3813

    Article  Google Scholar 

  • FitzJohn RG, Armstrong TT, Newstrom-Lloyd LE, Wilton AD, Cochrane M (2007) Hybridisation within Brassica and allied genera: evaluation of potential for transgene escape. Euphytica 158:209–230

    Article  Google Scholar 

  • Hansen LB, Siegismund HR, Jørgensen RB (2001) Introgression between oilseed rape (Brassica napus L.) and its weedy relative B. rapa L. in a natural population. Genet Res Crop Evol 48:621–627

    Article  Google Scholar 

  • Hansen LB, Siegismund HR, Jørgensen RB (2003) Progressive introgression between Brassica napus (oilseed rape) and B. rapa. Heredity 91:276–283

    Article  CAS  Google Scholar 

  • Hauser TP, Jørgensen RB, Østergård H (1997) Preferential exclusion of hybrids in mixed pollinations between oilseed rape (Brassica napus) and weedy B. campestris (Brassicaceae). Amer J Bot 84:756–762

    Article  Google Scholar 

  • Hauser TP, Shaw R, Østergård H (1998a) Fitness of F1 hybrids between weedy Brassica rapa and oilseed rape (B. napus). Heredity 81:429–435

    Article  Google Scholar 

  • Hauser TP, Jørgensen RB, Østergård H (1998b) Hybridization between weedy populations of Brassica campestris and varieties of oilseed rape (B. napus) II Fitness of backcross and F2 progeny. Heredity 81:436–443

    Article  Google Scholar 

  • Hauser TP, Damgaard C, Jørgensen RB (2003) Frequency dependent fitness of hybrids between oilseed rape (Brassica napus) and weedy B. rapa (Brassicaceae). Amer J Bot 90:571–578

    Article  Google Scholar 

  • Heenan PB, Dawson PB (2005) Spontaneous hybrids between naturalised populations of pak choi (Brassica rapa var. chinensis) and wild turnip (B. rapa var. oleifera) from near Ashburton, Canterbury, New Zealand. New Zeal J Bo 43:817–824

    Google Scholar 

  • Hooftman DAP, Jørgensen RB, Østergård H (2007) An empirical demographic model estimating reciprocal transgene introgression among oilseed rape and Brassica rapa. Proc. GMCC III, Seville, Spain, pp 304–305

  • Johannessen MM, Andersen BA, Jørgensen RB (2006a) Competition affects transmission of transgenes from transplastomic oilseed rape to weedy Brassica rapa. Heredity 96:360–367

    Article  CAS  Google Scholar 

  • Johannessen MM, Andersen BA, Jørgensen RB (2006b) Competition affects the production of first backcross offspring on F1 hybrids Brassica napus x B. rapa. Euphytica 150:17–25

    Article  Google Scholar 

  • Jørgensen RB, Andersen B (1994) Spontaneous hybridization between oilseed rape (Brassica napus) and weedy B. campestris (Brassicaceae). Amer J Bot 81:1620–1626

    Article  Google Scholar 

  • Jørgensen RB, Ammitzbøll H, Hansen LB, Johannesen M, Andersen B, Hauser TP (2004) Gene introgression and consequences in Brassica. In: Nijs HCM, Bartsch D, Sweet J (eds) Introgression from genetically modified plants into wild relatives. CABI, UK, pp 253–262

    Google Scholar 

  • Jørgensen T, Hauser TP, Jørgensen RB (2007) Adventitious presence of other varieties in oilseed rape (Brassica napus) from seed banks and certified seed. Seed Sci Res 17:115–125

    Article  Google Scholar 

  • Kathuria H, Giri J, Tyagi H, Tyagi AK (2007) Advances in transgenic rice biotechnology. Crit Rev Plant Sci 26:65–103

    Article  CAS  Google Scholar 

  • Landbo L, Jørgensen RB (1997) Seed germination in weedy Brassica campestris and its hybrids with B. napus; implications for risk assessment of oilseed rape. Euphytica 97:209–216

    Article  Google Scholar 

  • Landbo L, Andersen B, Jørgensen RB (1996) Natural hybridisation between oilseed rape and a wild relative: hybrids among seeds from weedy B. campestris. Hereditas 125:89–91

    Article  Google Scholar 

  • Lu CM, Kato M, Kakihara F (2002) Destiny of a transgene escape from Brassica napus into Brassica rapa. Theor Appl Genet 105:78–84

    Article  CAS  Google Scholar 

  • Mikkelsen TR, Andersen B, Jørgensen RB (1996) Spread of transgenes. Nature 380:31

    Article  CAS  Google Scholar 

  • Pallett DW, Huang L, Cooper JI, Wang H (2006) Within-population variation in hybridisation and transgene transfer between wild Brassica rapa and Brassica napus in the UK. Annal Appl Biol 148:147–155

    Article  CAS  Google Scholar 

  • Pertl M, Hauser TP, Damgaard C, Jørgensen RB (2002) Male fitness of oilseed rape Brassica napus, weedy B. rapa and their F1 hybrids in mixed populations. Heredity 89:212–218

    Article  CAS  Google Scholar 

  • Snow AA, Andersen B, Jørgensen RB (1999) Costs of transgenic herbicide resistance introgressed from Brassica napus into weedy Brassica rapa. Molec Ecol 8:605–615

    Article  Google Scholar 

  • Tomiuk J, Hauser TP, Jørgensen RB (2000) A- or C-chromosomes does it matter for the transfer of transgenes from Brassica napus? Theor Appl Genet 100:750–754

    Article  Google Scholar 

  • Warwick SI, Légère A, Simard M-J, James T (2008) Do escaped transgenes persist in nature? The case of an herbicide resistance transgene in a weedy Brassica rapa population. Molec Ecol 17:1387–1395

    Article  CAS  Google Scholar 

  • Weekes R, Allnutt T, Boffey C, Morgan S, Bilton M, Daniels R, Henry C (2007) A study of crop-to-crop gene flow using farm scale sites of fodder maize (Zea mays L.) in the UK. Transgen Res 16:203–211

    Article  CAS  Google Scholar 

  • Wilkinson MJ, Elliott LJ, Allainguillaume J, Shaw MW, Norris C, Welters R, Alexander M, Sweet J, Mason DC (2003) Hybridization between Brassica napus and B. rapa on a National scale in the United Kingdom. Science 302:457–459

    Article  CAS  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Rikke Bagger Jørgensen.

Additional information

Responsible editors: Winfried Schröder and Gunther Schmidt

Overview of the series, thematically oriented: (1) The variability of processes involved in transgene dispersal: case studies from Brassica and related genera Rikke Bagger Jørgensen, Thure Hauser, Tina D’Hertefeldt, Naja Steen Andersen, Danny Hooftman. (2) Cumulative impact of GM herbicide tolerant cropping on arable plants assessed through species-based and functional taxonomies Geoffrey Squire, Graham Begg, Cathy Hawes, Mark Young. (3) Farmer knowledge and a priori risk analysis: pre-release evaluation of genetically modified roundup ready wheat across the Canadian prairies Ian Mauro, Stéphane McLachlan, Rene C. Van Acker. (4) Dispersal and persistence of genetically modified oilseed rape around Japanese harbours Masaharu Kawata, T. Ishikawa, Kikuku Murakami. (5) Hazard mitigation or mitigation hazard? Would genetically modified dwarfed oilseed rape (Brassica napus) increase feral survival? Hauke Reuter, Gertrud Menzel, Hendrik Pehlke, Broder Breckling. (6) How to model and simulate the effects of cropping systems on population dynamics and gene flow at the landscape level: example of oilseed rape volunteers and their role for co-existence of GM and non-GM crops Nathalie Colbach

Rights and permissions

Reprints and permissions

About this article

Cite this article

Jørgensen, R.B., Hauser, T., D’Hertefeldt, T. et al. The variability of processes involved in transgene dispersal—case studies from Brassica and related genera. Environ Sci Pollut Res 16, 389–395 (2009). https://doi.org/10.1007/s11356-009-0142-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11356-009-0142-4

Keywords

Navigation