Abstract: 【Objective】The cytochrome P450 family is an important enzyme system involved in glucosinolate synthesis in cruciferous
plants, wherein the CYP83 subfamily plays a predominant role in core structure formation.【Method】The CYP83B1 gene was cloned from Chinese cabbage（Brassica rapa ssp. pekinensis）using RT-PCR technology to investigate its functional role. Bioinformatics analysis software was utilized to predict the encoded protein’s physicochemical properties, homology of the encoded protein, and promoter cis-acting elements. The expression pattern of BrCYP83B1 was analyzed by RT-qPCR, and a plant overexpression vector was constructed for further experimentation.【Result】The cDNA length of BrCYP83B1 was 1 500 bp, encoding a total of 499 amino acids. The protein belonged to cytochrome P450 superfamily and predominantly located in the cytoplasm. Its secondary structure primarily comprised of α-helixes and irregular coil. Homologous comparison illustrated that BrCYP83B1 had close relationship with Brassica napus L and Brassica oleracea L. var. italica. The BrCYP83B1 promoter contained cis-acting elements that were involved in the response to salicylic acid（SA）, abscisic acid（ABA）, and methyl jasmonate（MeJA）, suggesting that the expression of BrCYP83B1 gene may be regulated by hormones. The expression of BrCYP83B1 was detected in various plant organs, including roots, stems, leaves, flowers and fruits from RT-qPCR results. Notably, the highest expression was observed in leaves. Moreover, BrCYP83B1 significantly presented induction upon treatment with MeJA, while its expression was repressed by SA. Additionally, ABA treatment initially up-regulated and subsequently down-regulated the gene.【Conclusion】BrCYP83B1 may be involved in the response regulation of Chinese cabbage to hormones.

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