Abstract:

Used the Cre/loxp to establish inducible expression systems with site-specific recombination ability，to eliminate the selectable marker genes in transgenic plants specifically. Firstly，a binary expression vector PBI121-Cre-GUS with the Cre/loxp system was constructed to eliminate a marker gene from transgenic plants conveniently by digesting three intermediate vector and pBI121. Secondly，transgenic Malus hupehensis var. pinyiensis were obtained by using Agrobacterium mediated leaf disc method. These transgenic plants were induced by heat shock. Subsequently，the elimination efficiency was determined by GUS staining and PCR amplification. Finally，the transgenic plants without selectable marker gene were obtained.

Key words: Malus hupehensis var. pinyiensis, tobacco, Cre/loxp recombination excision system, marker-free selectable gene