title: Development of a simple and efficient system for excising selectable markers in Arabidopsis using a minimal promoter::Cre fusion construct.
abstract: The development of rapid and efficient strategies to generate selectable marker-free transgenic plants could help increase the consumer acceptance of genetically modified (GM) plants. To produce marker-free transgenic plants without conditional treatment or the genetic crossing of offspring, we have developed a rapid and convenient DNA excision method mediated by the Cre/loxP recombination system under the control of a -46 minimal CaMV 35S promoter. The results of a transient expression assay showed that -46 minimal promoter::Cre recombinase (-46::Cre) can cause the loxP-specific excision of a selectable marker, thereby connecting the 35S promoter and β-glucuronidase (GUS) reporter gene. Analysis of stable transgenic Arabidopsis plants indicated a positive correlation between loxP-specific DNA excision and GUS expression. PCR and DNA gel-blot analysis further revealed that nine of the 10 tested T(1) transgenic lines carried both excised and nonexcised constructs in their genomes. In the subsequent T(2) generation plants, over 30% of the individuals for each line were marker-free plants harboring the excised construct only. These results demonstrate that the -46::Cre fusion construct can be efficiently and easily utilized for producing marker-free transgenic plants.
authors: Graduate School of Biotechnology and Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea.
authors: Hyun-Bi
authors: HB
authors: Kim
authors: Jung-Il
authors: JI
authors: Cho
authors: Nayeon
authors: N
authors: Ryoo
authors: Shaohong
authors: S
authors: Qu
authors: Guo-Liang
authors: GL
authors: Wang
authors: Jong-Seong
authors: JS
authors: Jeon
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: C045073:Cre recombinase; D019426:Integrases