Abstract
The ARF gene family is crucial for regulating plant growth, development, and responses to various signaling pathways. In this study, 26 quinoa ARF genes (CqARF01-CqARF26) were identified, with encoded proteins varying in length from 553 to 1092 amino acids, molecular weights from 60.66 to 111.71 kDa, and isoelectric points from 5.15 to 8.21. The proteins were found in either the nucleus (13 CqARFs) or cytoplasm (11 CqARFs). Phylogenetic analysis classified ARF proteins into five groups. All CqARFs contained seven conserved motifs (Motif1, Motif2, Motif4, Motif6, Motif8, Motif9, and Motif10), indicating conserved positions and functional similarities. Gene structure analysis showed that most CqARF genes had UTR regions at both ends, with similar structures within subgroups. Conserved sequence analysis revealed that motif composition within subgroups was relatively conserved. The presence of four classes of cis-regulatory elements in quinoa ARF genes suggests involvement in light, hormone, tissue-specific expression, and other responses. Expression analysis indicated that the most genes (CqARF05, CqARF07, CqARF15 and CqARF24) were highly expressed under drought and salt stress treatment. Overexpression of CqARF05 gene in Arabidopsis enhanced drought and salt resistance in transgenic lines. These findings provide valuable insights into the role of the ARF gene family.