MdABCI17 acts as a positive regulator to enhance apple resistance to Botryosphaeria dothidea

The ATP-binding cassette (ABC) superfamily is involved in numerous complex biological processes. However, the understanding of ABCs in plant pathogen defense, particularly against Botryosphaeria dothidea, remains limited. In this study, we identified MdABCI17 that plays a positive role in apple resistance to B. dothidea. Overexpression of MdABCI17 significantly enhanced the resistance of apple calli and fruits to B. dothidea. Our findings revealed that the jasmonic acid (JA) content and the expression of genes associated with JA biosynthesis and signal transduction were higher in stable MdABCI17-overexpressing apple calli than that of wild-type after inoculation with B. dothidea. Similar results were obtained for apple fruits with transient overexpression of MdABCI17. Our research indicates that MdABCI17 enhances apple resistance to B. dothidea through the JA signaling pathway. We further determined that MdABCI17 plays a crucial role in the apple’s response to JA signaling. Moreover, exogenous methyl jasmonate (MeJA) treatment significantly enhanced the effectiveness of MdABCI17 in boosting apple resistance to B. dothidea. We proposed a positive feedback regulatory loop between MdABCI17-mediated apple resistance to B. dothidea and JA signal. In summary, our study offers new insights into the role of ABC superfamily members in the control of plant disease resistance.