Recent Developments in Generation of Marker-Free Transgenic Plants
A plant modified through artificial insertion of a foreign DNA into its genome is referred to as “genetically modified plant” or a “transgenic” plant. The selection of the transgenic tissues during the genetic transformation process is based on the constitutively expressed marker gene(s) coding for reporters, such as those conferring resistance against antibiotics and/or herbicides. In this direction, Agrobacterium-mediated genetic co-transformation is arguably the most commonly used technique to transfer the gene(s) of interest as well as the marker gene(s). However, the latter is purposeless once a transgenic tissue has been selected. Although these marker genes are important for screening purposes, they exhibit safety concerns for the environment as well as among consumers. At times, commercial transgenic plants transfer these gene(s) to the weeds or other organisms, leading to the development of resistance among nontarget plants. Moreover, the escape of such gene could affect the wild relatives or land races via gene flow. Therefore, in order to maintain sustainability, removing the marker gene(s) from a transgenic crop is of utmost importance, prior to its commercialization. Hitherto, several methodologies have been evolved for the development of a marker-free transgenic crop. In the present summary, we discuss the merits and the shortcomings of the Agrobacterium-mediated genetic co-transformation. In addition, we review the recent developments among other approaches and their impacts and suggest directions for their maximum utilization in the near future.
KeywordsMarker-free Transgenic plant Agrobacterium-mediated genetic co-transformation Gene flow
The authors would like to acknowledge the support from Projeto NORTE-01-0145-FEDER000017- INTERACT/ VitalityWINE, cofinanced by FEDER/Programa NORTE 2020, and Plataforma de inovação da vinha e do vinho-innovine&wine, Norte-01-0145-FEDER000038. Postdoctoral research grant (BPD/UTAD/INNOVINE&WINE/ 424/2016) to RKS is also acknowledged. Financial support (PEst-OE/QUI/UI0616/2014) provided to the Research Unit in Vila Real by Fundaçãopara a Ciência e Tecnologia (FCT), Portugal, and COMPETE is also acknowledged. Assistances from the project UID/AGR/04033/2013 and National Funds by FCT (Portuguese Foundation for Science and Technology) and the European Investment Funds by FEDER/COMPETE/POCI Operacional Competitiveness and Internationalization Programme under the Project POCI-01-0145-FEDER-006958 are also recognized. Chemistry center of Vila Real (CQ-VR) is gratefully acknowledged.
Conflict of Interest
The authors declare that there are no conflicts of interest.
- FAO, Food and Agriculture Organization/World Health Organization (2000) Safety aspects of genetically modified foods of plant origin. Report of a joint FAO/WHO consultation on foods derived from biotechnology. World Health Organization, GenevaGoogle Scholar
- Gilbertson LA, Huang S, Malver T (2018) Recombinant DNA constructs employing site – specific recombination United States Patent 9856485Google Scholar
- Goodwin J, Pastori G, Davey M, Jones H (2004) Transgenic plants: methods and protocols. Method Mol Biol 286:191–202Google Scholar
- Jaiwal PK, Sahoo L, Singh ND, Singh RP (2002) Strategies to deal with the concern about marker genes in transgenic plants: some environmentally friendly approaches. Curr Sci 83:128–136Google Scholar
- Khidr YA, Nasr MI (2018) Generation of transgenic marker-free cucumber plants by co-transformation strategy. Egyptian J Genet Cytol 47:29–43Google Scholar
- Malca I, Endo RM, Long MR (1967) Mechansim of glucose counteraction of inhibition of root elongation by galactose, mannose and glucosamine. Phytopathology 57:272–278Google Scholar
- National Research Council (US) Committee on Genetically Modified Pest-Protected Plants (2000) ‘Genetically modified pest-protected plants: science and regulation’, Washington D.C: National Academy Press, p 1–246Google Scholar
- Oliva N, Chadha-Mohanty P, Poletti S, Abrigo E, Atienza G, Torrizo L, Garcia R, Dueñas CJ, Poncio MA, Balindong J, Manzanilla M, Montecillo F, Zaidem M, Barry G, Hervé P, Shou H, Slamet-Loedin IH (2014) Large-scale production and evaluation of marker-free indica rice IR64 expressing phytoferritin genes. Mol Breed 33:23–37PubMedCrossRefGoogle Scholar
- Palomo-Ríos E, Quesada MA, Matas AJ, Pliego-Alfaro F, Mercado JA (2018) The history and current status of genetic transformation in berry crops. In: Hytönen T, Graham J, Harrison R (eds) The genomes of rosaceous berries and their wild relatives. Compendium of Plant Genomes. Springer, East Malling, pp 139–160CrossRefGoogle Scholar
- Ran Y, Patron N, Kay P, Wong D, Buchanan M, Cao Y, Sawbridge T, Davies JP, Mason J, Webb SR, Spangenberg G, Ainley WM, Walsh TA, Hayden MJ (2018) Zinc finger nuclease-mediated precision genome editing of an endogenous gene in hexaploid bread wheat (Triticumaestivum) using a DNA repair template. Plant Biotechnol J 16:2088–2101PubMedPubMedCentralCrossRefGoogle Scholar
- Royal Society (1998) Genetically modified plants for food use. The Royal Society, LondonGoogle Scholar
- Shah P, Singh NK, Khare N, Rathore M, Anandhan S, Arif M, Singh RK, Das SC, Ahmed Z, Kumar N (2008) Agrobacterium mediated genetic transformation of summer squash (Cucurbita pepo L. cv. Australian green) with cbf-1using a two vector system. Plant Cell Tissue Organ Cult 95:363–371CrossRefGoogle Scholar
- Sonntag K, Wang Y, Wallbraun M (2004) A transformation method for obtaining marker-free plants based on phosphomannose isomerase. Acta Universitatis Latviensis Biol 676:223–226Google Scholar
- Sripriya R, Raghupathy V, Veluthambi K (2008) Generation of selectable marker-free sheath blight resistant transgenic rice plants by efficient co-transformation of a cointegrate vector T-DNA and a binary vector T-DNA in one Agrobacterium tumefaciens strain. Plant Cell Rep 27:1635–1644PubMedCrossRefPubMedCentralGoogle Scholar
- Verruto J, Francis K, Wang Y, Low MC, Greiner J, Tacke S, Kuzminov F, Lambert W, McCarren J, Ajjawi I, Bauman N, Kalb R, Hannum G, Moellering ER (2018) Unrestrained markerless trait stacking in Nannochloropsis gaditana through combined genome editing and marker recycling technologies. Proc Natl Acad Sci U S A 115:7015–7022CrossRefGoogle Scholar
- Wright M, Dawson J, Dunder E, Suttie J, Reed J, Kramer C, Chang Y, Novitzky R, Wang H, Artim-Moore L (2001) Efficient biolistic transformation of maize (Zea mays L.) using the phosphomannoseisomerase gene, pmi, as the selectable marker. Plant Cell Rep 20:429–436PubMedCrossRefPubMedCentralGoogle Scholar
- Zhu Q, Yu S, Zeng D, Liu H, Wang H, Yang Z, Xie X, Shen R, Tan J, Li H, Zhao X, Zhang Q, Chen Y, Guo J, Chen L, Liu YG (2017) Development of “purple endosperm rice” by engineering anthocyanin biosynthesis in the endosperm with a high-efficiency transgene stacking system. Mol Plant 10:918–929PubMedCrossRefPubMedCentralGoogle Scholar