Abstract
The AINTEGUMENTA-LIKE (AIL) family is a current research hotspot in plant molecular biology, primarily focusing on its potential applications in crop genetic improvement. It plays roles in plant embryogenesis, meristem maintenance, organ growth regulation, and cross-talk with hormone signaling pathways. However, the members and functions of AIL genes in Eucalyptus grandis remain uncharacterized. In this study, a genome-wide characterization of the AIL family in E. grandis was performed using bioinformatics methods, resulting in the identification of 19 AIL members (EgAIL1A-EgAIL16). All members contain the characteristic APETALA 2(AP2) conserved domain and were classified into the AP2/ERF superfamily. Phylogenetic analysis revealed that these genes are most closely related to PtrAILs from Populus trichocarpa, and they clustered into five subgroups. Based on cis-acting element analysis, tissue-specific expression profiles, and stress treatment assays, EgAIL3 was identified as a positive regulator of salt tolerance; while EgAIL16 is predicted to be involved in regulating early root and leaf development regulation and contains an endodermis-specific negative regulatory element. This study provides a foundation for understanding the AIL family and a theoretical basis for refining E. grandis somatic embryogenesis.