The invention discloses a method for preparing a
promoter (PBnPABP2) of
Brassica napus BnPABP2 and the application thereof. The operation of
cloning a PBnPABP2 sequence by using a
genome walking method comprises the following steps: extracting
genome DNA by using a SDS
cracking process; in different systems, carrying out restriction
endonuclease reaction on the extracted
DNA respectively by using endonucleases DraI, EcoRV, PvuII and StuI; after the obtained
DNA is connected with a
linker fragment, carrying out first-round PCR amplification by taking the
linker fragment as a template; and carrying out second-round PCR amplification by taking a50-time
diluent of the obtained first-round PCR product as a template, thereby obtaining the PBnPABP2. The PBnPABP2 is applied in the roots, stems, leaves, flower buds, anthers and peels of plants. The
promoter has the function of driving the expression of exogenous genes, and the expression sites thereof are respectively in the roots, stems, leaves, flower buds, anthers and peels of plants; and the
promoter has application potentials in the aspect of safety of
edible oil of
Brassica napus and the aspects of improving the
disease resistance,
stress resistance and lodging resistance of crops, improving the quality of crops, artificially creating a male sterile line and a restoring line, enriching
germ plasm resources, and the like through transgenosis.