A novel eggplant AP2/ERF transcription factor StPti5 confers resistance to Verticillium wilt across different species

The APETALA 2/ethylene response factors (AP2/ERFs) are considered essential in plant disease resistance responses. In this study, a novel eggplant AP2/ERF transcription factor gene, StPti5, was identified and functionally described from wild eggplant (Solanum torvum Sw.). The results of bioinformatics analysis show that StPti5 protein contains a DNA-binding AP2/ERF domain and shares high degree of amino acid similarity with the other known AP2/ ERF domain. Subcellular localization assay shows that StPti5 protein was localized in the nucleus. Expression of StPti5 was induced by infection with Verticillium dahliae, ethylene, and methyl jasmonate. Analysis of expression patterns suggests that the function of StPti5 in resistance to Verticillium wilt was most closely linked to ethylene signaling. Overexpression of StPti5 in Arabidopsis thaliana could improve disease resistance to V. dahliae and activate genes linked to the ethylene signaling pathway. Studies on the A. thaliana defence response revealed that the formation of reactive oxygen species (ROS) increased considerably following overexpression of StPti5. In summary, our analysis suggest that StPti5 gene is a functional gene that could improve eggplant's resistance to V. dahliae.