采用生物信息学的方法,通过已知防御素基因家族基因氨基酸序列在线Blast相似性比对,对白菜(Brassicarapa)基因组中防御素基因进行了预测和鉴定,分析了防御素基因在进化过程中各部分结构,包括上游区域、启动子区域、外显子区域、内含子区域以及UTR区域的结构变异以及功能变异,对该基因上游序列顺式作用元件和表达模式进行了预测。分析结果表明,白菜防御素基因编码60～80个氨基酸短肽,编码氨基酸均具有8个保守的半胱氨酸;白菜防御素基因功能结构域保持相对稳定,但部分基因成员前端信号肽序列出现变异;内含子长度出现增长、缩短、消失等3种变异模式;该基因上游启动子区域核苷酸变异较其他区域显著,上游序列顺式作用元件大多与光应答、逆境胁迫应答和信号分子应答相关。该基因表达模式预测结果表明白菜防御素基因在进化过程中可能出现分化,主要体现在基因沉默和表达部位的差异。 Bioinformatics methods were used to predict and identify the defensin genes in Brassicarapa genome by online Blast similarity alignment of amino acid sequences of known defensin gene family genes. The defensin genes were analyzed in the process of evolution Partial structure, including the upstream region, promoter region, exon region, intronic region and UTR region structural variation and functional variation, upstream of the gene sequence cis-acting elements and expression patterns were predicted. The results showed that the cabbage defensin gene encoded 60 to 80 amino acid short peptides, and the encoded amino acids all contained 8 conserved cysteines. The functional domains of cabbage defensin genes remained relatively stable, however, the signal peptide sequences of the front of some members appeared The length of intron was increased, shortened and disappeared. The nucleotide variation of the upstream promoter was significantly higher than that of other regions. Most of the upstream cis-acting elements were related to light response, stress response and signal molecules Response related. The prediction of the gene expression pattern shows that the defensive genes of cabbage may differentiate during evolution, which is mainly reflected in the differences of gene silencing and expression sites.