AP2/ERF Transcription Factors in Crop Plants' Disease Resistance Response

Biotic stresses include the infestation of crops by an array of pathogenic microbes like bacteria, viruses, fungi, nematodes, and insect pests. Pathogenic microbes have always threatened crop plants and their produce. With the growing global population and changing environmental conditions, there is a need for crops that can tolerate stress. Over the years, significant progress has been made in elucidating the functional role of the major transcription factors (TFs) families in plant disease resistance. Among the TFs, the APETALA2/ethylene response factor (AP2/ERF) family members have emerged as pivotal regulators of plant growth, development, and responses to environmental stresses. AP2/ERF transcription factors are key regulators of plant disease resistance, integrating pathogen signals to mediate salicylic acid (SA), jasmonic acid (JA), and ethylene (ET) pathways, activate defense genes, enhance reactive oxygen species (ROS) production, and modulate cell wall defenses for effective immune responses. They influence immune responses by modulating hypersensitive reactions and serving as virulence targets for pathogen effectors. By enhancing defense responses, AP2/ERF TFs contribute to developing genetically improved crops with increased resistance to biotrophic and necrotrophic pathogens, thereby reducing crop losses and improving yield stability under disease pressure. This review offers a comprehensive overview of the current understanding of AP2/ERF transcription factors in defense responses to microbial pathogens to plant disease resistance by acting downstream of mitogen-activated protein kinase (MAPK) cascades. It also emphasizes recent developments and outlines future research directions to enhance disease resistance.