Genomic identification of ARF transcription factors and expression analysis in Cannabis sativa L

Auxin response factors (ARFs) participate in the regulation of auxin signaling by binding directly to the auxin response elements (AuxREs) in the promoter regions of the downstream auxin response genes during plant development. To date, ARF genes in Cannabis sativa L. (cannabis) have not been characterized. The present study identified 21 ARF gene family members based on the genome-wide database of cannabis. Systematic analysis of these CsARFs included analysis of the gene structures, conserved domains, possible isoforms, phylogeny, cis -elements, and expression levels in various tissues and subspecies of cannabis. Currently, the function of the ARF genes in the growth and development of cannabis is largely unknown. To uncover this function, the expression patterns of the CsARF genes were analyzed in various tissues and subspecies of cannabis in detail. Combination of the results of the evolutionary tree and expression patterns of CsARFs , the functions of five CsARFs ( CsARF7, CsARF8, CsARF11, CsARF19, and CsARF20 ) were predicted, and these genes may be involved in the development of cannabis flower. In addition, six CsARFs ( CsARF3 , CsARF5 , CsARF7 , CsARF8 , CsARF10 , and CsARF15 ) may be involved in the development of cannabis root and stem. Ultimately, CsARF13 may be involved in the development of cannabis leaf. The present study provides basic information on the CsARF genes and paves the way for further exploration of the function and mechanisms involved in the regulation of the growth and development of cannabis. • 21 ARF gene family members were identified in cannabis genome. • The genes exhibit different expression level in various tissues. • Five CsARFs were predicted to be involved in the regulatory process of flower organ development. • Six CsARFs may be related to the growth and development of roots and stems in cannabis. • One CsARF was predicted that possibly participated in the development of cannabis leaf.