Abstract:The immature embryos of maize can form embryogenic callus through tissue culture, and are usually used as explants for genetic transformation. It is not well known about the molecular mechanism of maize embryonic callus formation. To reveal the potential genes involved in the callus formation of maize, type I calli with well growth and type II calli with poor growth from F3 embryos of maize inbred line CAL28× Zheng58 were selected for RNA-seq analysis. Compared to type II calli, there were 4419 differentially expressed genes (DEGs) in type I calli, including 1571 upregulated genes and 2848 downregulated genes. The results of GO enrichment analysis showed that DEGs were mainly enriched in response to stimulus, cell components and catalytic activity pathways. KEGG enrichment analysis showed that the enrichment of DEGs were mainly involved in phenylpropanoid biosynthesis and the plant hormone signal transduction pathway. The SAUR family, ZIM family and IAA growth hormone response factors were upregulated in type I callus. A total of 2968 transcription factors belonging to 56 transcription factor families in DEGs were significantly enriched. The expression levels of EREB24, EREB53, EREB184, EREB206, ZmLBD10, ZmLBD24, ZmLBD31 and ZmLBD32, which are from AP2, WOX and LBD transcription factor families, were significantly up-regulated in type Ⅰ callus. Genetic manipulation of these target genes may promote the formation of maize callus.The results provide theoretical reference for the analysis of molecular mechanism of maize callus formation, and the identified candidate DEGs would have great application potential.