Abstract:To reveal the function of the maize transcription factor KNOX, this study used the bioinformatics method to identify the KNOX family members at the maize genome level and analyzed the expression profile of family gene response to stress and the tissuespecific. The results showed that: (1) there were 22 ZmKNOX genes in the maize genome named ZmKNOX1ZmKNOX22 according to their positions on the chromosome. The subcellular localization prediction of coding proteins showed that all the other family proteins located in the nucleus, except ZmKNOX5, ZmKNOX11, ZmKNOX12, and ZmKNOX15, found in mitochondria and ZmKNOX7 in the cytoplasm. The phylogenetic tree analysis showed that most ZmKNOX and sorghum were clustered in the same branch, indicating that the phylogenetic relationship between the two species was close. There was a specific correlation between the gene structure and the protein evolutionary classification. (2) The tissue expression profile analysis of the whole growth period showed that ZmKNOX had different expression patterns. The expression patterns of the genes during the growth period were correlated with the evolutionary classification of proteins. ZmKNOX13, ZmKNOX20, ZmKNOX1, and ZmKNOX21 were constitutively high in the whole growth period, while ZmKNOX3, ZmKNOX5, ZmKNOX6, and ZmKNOX14 were constitutively low in the whole growth period. ZmKNOX4, ZmKNOX8, ZmKNOX9, and ZmKNOX1719 expressed in certain stages and tissues of plant growth and development, including the embryo, seed germination stage, germ sheath, shoot tip, shoot internode, apical meristem, and inflorescence. Further coexpression analysis of the growth period data showed that the module in which ZmKNOX13 was closely related to the biological process of ubiquitination. (3) Eight ZmKNOX family genes showed different response patterns under salt, cold, heat, and UV treatments, while the gene expression levels did not change significantly. Among them, ZmKNOX6 was significantly upregulated under cold treatment, ZmKNOX14 was significantly downregulated under heat treatment, ZmKNOX13 was significantly upregulated, while ZmKNOX3 and ZmKNOX14 were significantly downregulated under salt stress. All the above three genes were low expression during the growth period. (4) The sequencing data analysis showed that the expression patterns of upregulated ZmKNOX3 and ZmKNOX13 genes in leaves and downregulated ZmKNOX3, ZmKNOX6, and ZmKNOX17 genes in roots were the same under salt treatment. ZmKNOX3 was stable in leaves and roots at different treatment time points, but the expression patterns were opposite. These results showed that ZmKNOX family genes play an essential role in maize growth, development and stress response.