Genome-Wide Identification and Bioinformatics Analysis of ADF Gene Family in Soybean

Zhang Feng; Wang Hongdui; Zhang Zhongqi; Gao Fazhen

doi:10.14083/j.issn.1001-4942.2025.06.002

Abstract：Actin depolymerizing factor(ADF)plays a critical role in plant growth,development and stress responses.However,systematic studies on ADF genes in soybean remain limited.In this study,we con-ducted genome-wide identification of the soybean ADF gene family using bioinformatics tools such as HM-MER3.0,MCScanX and MEGA 11,and analyzed their physicochemical properties,gene structures,con-served motifs,chromosomal distribution,evolutionary relationships,and expression patterns.The results indi-cated that a total of 18 ADF genes were identified in the soybean genome,named GmADF1 to GmADF18.The encoded protein sequences ranged from 117 to 169 amino acids(aa)in length with molecular weight between 13.80 and 19.49 kDa and theoretical isoelectric points(pI)spanning from 5.13 to 7.93.All the proteins were hydrophilic proteins and were localized in cytoplasm,exhibiting highly conserved motifs.The genes contained 2 or 3 exons.Chromosomal mapping revealed that these 18 ADF genes were distributed across 13 chromosomes with the most(3 genes)located on chromosome 10.Collinearity analysis identified 25 pairs of paralogous ADF genes,whose evolution was primarily driven by purifying selection.Phylogenetic analysis classified the soybean ADF proteins into five subfamilies,and the closest evolutionary relationship was observed between soybean and wild soybean.Promoter analysis uncovered abundant stress-responsive cis-elements and hormone-responsive cis-elements,suggesting their potential involvement in diverse stress responses.Protein interaction networks in-dicated that soybean ADF proteins interacted with actin and POZ domain-containing proteins,potentially par-ticipating in cytoskeletal dynamics regulation.Tissue-specific expression profiles highlighted high expression of certain genes in organs such as flowers,roots and seeds.Stress expression analysis showed that the expression of GmADF8,GmADF14 and GmADF 16 were significantly up-regulated under salt,drought and flooding stres-ses,while that of GmADF5 was inhibited under low temperature stress.The qRT-PCR analysis further valida-ted the expression patterns of soybean ADF genes under salt and drought stresses,revealing that GmADF2 ex-hibited up-regulated expression in response to early salt stress,while both GmADF2 and GmADF8 showed up-regulated expression in response to early drought stress.The results of this study could provide a crucial theo-retical foundation for exploring the functional mechanisms of soybean ADF genes in abiotic stress responses.