Genome-wide characterization, phylogenetic and expression analysis of ABCG gene subfamily in tomato

The ATP-binding cassette (ABC) G subfamily represents the largest subgroup within the ABC transporter family and plays a crucial role in plant stress responses as well as growth and development; however, its specific functions in tomatoes remain poorly understood. In this study, we systematically identified and classified 57 ABCG transporters in tomatoes into three distinct groups: A, B, and C. Analysis of the cis-acting elements within the promoters suggests that these genes participate in the response to various biological and abiotic stresses throughout tomato development. Phylogenetic, gene structure, and conserved motif analyses demonstrated that ABCG proteins are functionally conserved across plant species, while collinearity analysis further corroborated their evolutionary conservation. Tissue-specific analysis revealed that the ABCG gene exhibits high expression levels in the floral organs of various tomato varieties, which may indicate potential interacting proteins. These findings establish a foundation for further investigation into the function of the ABCG gene in tomatoes, provide insights for genomic design breeding, and offer a theoretical basis for understanding the influence of the ABCG gene on the reproductive growth of tomatoes.