肉桂醇脱氢酶（CAD）是木质素生物合成途径的限速酶，对玉米B73基因组数据库和NCBI数据库中注释为玉米B73 CAD的基因进行挖掘和筛选，对其中一条玉米肉桂醇脱氢酶基因ZmCAD4克隆，并进行生物信息学分析。共筛选到12条玉米CAD基因，克隆的ZmCAD4基因编码区全长1104 bp，编码367个氨基酸。ZmCAD4蛋白含有典型的CAD1结构域、Zn结合位点和NADP结合位点，不含有跨膜结构域和信号肽，为非分泌蛋白，亚细胞定位预测定位在细胞质中。蛋白三级结构预测与拟南芥AtCAD5蛋白相似，相似度达到73.80%。系统进化分析表明ZmCAD4与芒草、高粱等禾本科植物亲缘关系最近。本研究结果为阐明玉米中木质素生物合成关键基因ZmCAD4的功能奠定了基础。

Cinnamyl alcohol dehydrogenase (CAD) is a rate-limiting enzyme in lignin biosynthesis pathway. The genes annotated CAD in the genome data of Zea Mays B73 and NCBI database were searched out, and a cinnamyl alcohol dehydrogenase gene ZmCAD4 was cloned and bioinformatically analyzed. A total of twelve ZmCAD genes were obtained. The length of the coding region of ZmCAD4 was 1104 bp, encoding 367 amino acids. ZmCAD4 protein contained typical CAD1 domain, Zinc binding site and NADP binding site, with no transmembrane domain and signal peptide. ZmCAD4 was a non-secreted protein, and it was predicted located in the cytoplasm. The tertiary structure of ZmCAD4 was similar to AtCAD5 protein, with a 73.80% similarity. The results of phylogenetic analysis showed that ZmCAD4 was closely related to Miscanthus floridulus and Sorghum bicolor. The results of this study laid the foundation for further analysis the function of ZmCAD4, a key gene for lignin biosynthesis in maize (Zea Mays L.).