The Identification and Expression Analysis of the . Auxin-Response Factor (ARF) Gene Family.

is a shrub that can survive in extreme drought environments. The auxin-response factors (ARFs) are a class of transcription factors that are widely involved in plant growth and development, as well as in the regulation of stress resistance. However, the genome-wide identification of the gene family and its responses to environmental stresses, especially drought stress, in has not yet been reported. Here, we identified a total of 12 genes in the genome of , which were distributed over 10 chromosomes and divided into three clades. Intragenome synteny analysis revealed one collinear gene pair in the gene family, i.e., and . Cis-acting element analysis showed that multiple hormones and stress-responsive cis-acting elements were found in the promoters of , suggesting that may be involved in multiple biological processes. Quantitative real-time PCR (qRT-PCR) showed that many had tissue-specific expression patterns, with the highest expression of in the seedlings of . In addition, most of the that were upregulated under drought were independent of endogenous ABA biosynthesis, whereas the response of and to drought was disrupted by the ABA-biosynthesis inhibitor fluridone. These studies provide a basis for further research into how in respond to hormonal signaling and environmental stresses.