Genome-wide identification, characterization and in-silico expression of AINTEGUMENTA-LIKE family in Eucalyptus grandis

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.