Genome-wide identification of wheat ABC gene family and expression in response to fungal stress treatment

The ATP-binding cassette (ABC) transporter family is one of the largest protein families in plants and plays an essential role in addressing biotic and abiotic stresses. Wheat, a vital global grain crop, faces multifaceted safety challenges, primarily from fungal diseases like stripe rust and powdery mildew. In the present study, we identified the whole genome of the wheat ABC family, and 463 nonredundant ABC genes were identified. The ABC family can be divided into nine evolutionary branches and eight subfamilies based on phylogenetic tree analysis. This paper delved deeper into characterizing the gene structure, promoter region, and gene expression within the TaABC family. Segmental duplication was the main reason for the expansion of the TaABC genes. Ka/Ks analysis suggested that most TaABC genes were intensely purified and selected. The collinear analysis of TaABC and other species showed that the ABC genes were conserved in evolution. RNA-seq data and qPCR data from wheat infected with powdery mildew or stripe rust showed that most TaABC genes were induced to change expression. The candidate genes TaABCB15-3B and TaABCG38 exhibited responsiveness to powdery mildew in resistant/susceptible wheat, while remaining unresponsive to stripe rust. Our findings serve as a valuable reference for gaining a deeper understanding of the function and evolution of TaABCs, aiding in the identification of enduring disease resistance genes within the TaABCs of wheat.