Genome-wide identification and expression analysis of ClKNOX gene family in watermelon

CHEN Yaxin; HU Aofeng; ZHANG Liming; LIU Quanquan; YANG Luming; ZHU Huayu; LIU Dong-ming

doi:10.16861/j.cnki.zggc.2024.0034

Abstract：KNOTTED-like homeodomain(KNOX)gene family is a class of transcription factors encoding homeobox pro-tein,which plays an important role in plant growth and stress responses.To further investigate the watermelon KNOX tran-scription factor family members,the bioinformatics methods was utilized to identify and analyze their physical and chemi-cal properties,gene structure,phylogeny,and expression patterns.The study revealed the presence of 12 KNOX genes in the watermelon genome,all of which were identified in the nucleus,the result was consistent with their characteristics as transcription factors.Most KNOX genes in watermelon exhibited the typical domains KNOX 1,KNOX2,ELK,and Ho-meobox_KN,suggesting the significance of these domains in KNOX gene functionality.Phylogenetic analysis categorized ClKNOX gene family members into four subgroups:ClassⅠA,ClassⅠB,ClassⅡA,and ClassⅡB.Analysis of promoter ele-ments indicated that the ClKNOX gene family harbored numerous cis-acting regulatory elements associated with growth,development,and stress response.The results of tissue expression analysis revealed distinct patterns for ClKNOX gene ex-pression.Specifically,ClKNOX6 and ClKNOX11 exhibited high expression levels in roots and stems,whereas ClKNOX3 and ClKNOX10 showed relatively high expression across all organs.However,all ClKNOX genes had low relative expres-sion levels in flesh.These findings provide a basis for future investigations into the functional roles and tissue-specific ex-pression patterns of ClKNOX genes in growth and development.