Ethanol inducible isopentenyl transferase as a high efficiency marker for tobacco transformation

Abstract

The isopentenyl transforase gene from Agrobacterium tumefaciens is one positive selectable marker genes for plant transformation. In this research, the ipt gene was placed under the control of ethanol-inducible system and was introduced into Nicotiana tabacum cv. Xanthi via Agrobacterium-mediated transformation. On a hormonefree medium (MSI) with 0.1% ethanol vapor, a large number of transgenic calli and shoots were obtained from explants that were infected with A. tumefaciens LBA4404 harboring the AlcA::ipt gene or 35S::ipt gene. On the same medium without inducer under identical culture conditions, explants can produce a larger number of calli and shoots transformed using 35S::ipt gene, but no calli or shoots were induced from explants transformed using AlcA::ipt gene. After being transferred to MSII medium, the AlcA::ipt transgenic plants displayed normal shoot morphology compared to the 35S::ipt transgenic plant lines. Our results demonstrated that ethanol-inducible ipt system can be used as a positive selection marker for tobacco plant transformation.

Key words: Selectable marker, ipt gene, ethanol inducible system, transformation.