Expression vector capable of efficiently deleting selectable marker gene of transgenic plant and construction method thereof

Abstract

The invention relates to the field of plant genetic engineering and provides an expression vector capable of efficiently deleting a selectable marker gene of a transgenic plant. The expression vector contains a Cre gene expression box, a selectable marker gene expression box, a promoter for driving a target gene, a terminator of the target gene and a polyclone site for inserting the target gene; the base sequence of the Cre gene is shown as SEQ ID NO: 1; and the Cre gene expression box and the selectable marker gene expression box are located between two equidirectional loxP sites. An introne of a catalase gene from a castor-oil plant is inserted to the Cre gene so that the expression of the Cre gene in microorganisms is prevented, the difficulty of constructing the expression vector is overcome, the efficiency of transforming plants by Agrobacterium tumefaciens is increased, and the cultivating efficiency of the transgenic plants is greatly increased.

Description

Technical field [0001] The present invention relates to the field of plant genetic engineering, in particular to an expression vector capable of efficiently deleting a transgenic plant selection marker gene and a construction method thereof. Background technique [0002] With the advancement of biotechnology, it has become a reality for people to use genetic engineering methods to modify plants to improve their quality, yield, and resistance levels. Especially in recent years, transgenic technology has advanced by leaps and bounds, and there are more and more genetically modified crops. The safety of genetically modified food has become one of the hot spots of public concern. For some reasons, people often do not want to contain foreign genes in certain plant organs. Especially in some edible parts, such as fruits and seeds, if they contain a certain foreign gene, the gene product may not be conducive to the quality improvement of edible organs, or may not be conducive to the s...

AI Technical Summary

Problems solved by technology

Although the method described in this invention is theoretically speaking, the recombinase is expressed in the specific organ or tissue of the plant, and cuts out the exogenous nucleotide sequence between the recognition sites in the expressed organ or tissue, while in other organs or tissues The exogenous target nucleotide sequence cannot be deleted in the tissue and the traits of the exogenous gene are guaranteed; however, in the actual operation process, the plant expression vector containing the recombinase gene and the vector containing the exogenous target gene need to be introduced into plant cells separately Among them, after the transgenic plants have survived and developed well, the two are crossed. The disadvantages are that the operation is complicated, the transformation and screening work is heavy, and the time required is long. In addition, this method is easy to cause cell variation, and the introduced genes are not tightly linked. , intractable Mendelian segregation between genes occurs in the offspring

[0005] In addition, after the expression vector is constructed, it is introduced into Agrobacterium, and the Cre protein will also be expressed during the cultivation of Agrobacterium, resulting in the loss of the complete Cre-LoxP system in many Agrobacteria. Not only are there difficulties in the vector construction process, also reduces the efficiency of Agrobacterium transformation of plants

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