Identification and Bioinformatics Analysis of KNOX Gene Family in Wheat (Triticum aestivum L.)

KNOTTED-like homeodomain ( KNOX ) gene family is a transcription factor encoding homeobox protein, which plays an important role in plant growth and morphogenesis. However, little information is available on the KNOX gene family in wheat ( Triticum aestivum L.). In this study, 36 KNOX genes with KNOX1 or KNOX2 domain distributed on 18 chromosomes were identified from wheat genome using bioinformatics methods. The phylogenetic evolution, gene structure, protein domains, cis-acting elements and gene expression patterns were analyzed in the present study. Based on the phylogenetic tree, the 36 TaKNOX genes were divided into two major subclasses, Class I and Class II, and the two subclasses were further divided into five evolutionary branches. Most TaKNOX genes contain four typical conserved protein domains: KNOX1, KNOX2, ELK and HOX. Some cis-acting elements are associated with hormonal, plant development and stress in TaKNOX promoters. The analysis result of transcriptome data from wheat different tissue showed that Class I KNOX genes had obvious tissue specificity, while Class II KNOX genes expressed widely in different wheat tissues. The study results provide important information for future analysis of the regulation and functions of the TaKNOX gene family.