A study of expression pattern of auxin response factor family genes in maize (<italic>Zea mays</italic> L.)

Auxin response factors (ARFs) are important transcription factors which control the expression of target genes by binding specifically to auxin response elements, and are involved in a series of developmental processes in plant species. In maize genome, dozens of ARF genes are encoded, however, there is little known on their expression patterns. In this study, the analysis on the expression level of ARF genes in diverse tissues and organs revealed that expression level of 32 ARF genes were higher in reproductive organs than that in vegetative organs, except ARF10, ARF16, and ARF34 constitutively expressed. The predicted results of cis-acting elements showed that the promoter regions of 28 ARF genes harbored the cis-regulatory elements related to abiotic stresses. Real-time quantitative PCR results indicated that expression of several ARF genes showed a response to cold, heat, and osmotic stresses, respectively. The results highlighted the importance of ARF family genes in reproductive growth and abiotic stress response, and provided useful information for the comprehensive analysis of the biological function of ARF genes in maize.