Abstract
Chemical inducible gene regulation systems provide essential tools for the precise regulation of transgene expression in plants and animals. Recent development of a two-hybrid ecdysone receptor (EcR) gene regulation system has solved some of the drawbacks that were associated with the monopartate gene switch. To further improve the versatility of the two-hybrid EcR gene switch for wide spread use in plants, chimeras between Homo sapiens retinoid X receptor (HsRXR) and insect, Locusta migratoria RXR (LmRXR) were tested in tobacco protoplasts as partners with Choristoneura fumiferana EcR (CfEcR) in inducing expression of the luciferase reporter gene. The RXR chimera 9 (CH9) along with CfEcR, in a two-hybrid format gave the best results in terms of low-background expression levels in the absence of ligand and high-induced expression levels of the reporter gene in the presence of nanomolar concentrations of the methoxyfenozide ligand. The performance of CH9 was further tested in corn and soybean protoplasts and the data obtained was compared with the other EcR switches that contained the wild-type LmRXR or HsRXR as EcR partners. In both transient expression studies and stable transformation experiments, the fold induction values obtained with the CH9 switch were several times higher than the values obtained with the other EcR switches containing LmRXR or HsRXR. The new CfEcR two-hybrid gene switch that uses the RXR CH9 as a partner in inducing reporter gene expression provides an efficient, ligand-sensitive and tightly regulated gene switch for plants.
Original language | English |
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Pages (from-to) | 599-612 |
Number of pages | 14 |
Journal | Transgenic Research |
Volume | 16 |
Issue number | 5 |
DOIs | |
State | Published - Oct 2007 |
Bibliographical note
Funding Information:Acknowledgments We thank Kay McAllister, Jeanne Prather, Elizabeth Foard, Samantha Childers and Ray Stevens for technical and greenhouse help. We would like to thank RheoGene Inc. for the Hs-LmRXR chimeras used in this study. We also thank Dr. Indu Maiti, University of Kentucky for providing tobacco and corn cell suspension cultures and for the plasmids containing MMV and FMV promoters and Dr. Jack Widholm, University of Illinois for providing soybean cell suspension cultures. This research is supported by funds provided by the Kentucky Tobacco Research and Development Center, University of Kentucky and the United Soybean Board. This paper (No. 06-06-030) is published with the approval of the Director of the Kentucky Agricultural Experiment Station.
Keywords
- Ecdysone receptor
- Methoxyfenozide
- RXR chimera
- Retinoid X receptor
- Transgenic plants
- Two-hybrid gene switch
ASJC Scopus subject areas
- Biotechnology
- Animal Science and Zoology
- Genetics
- Agronomy and Crop Science