Plant immunity and resistance mechanisms: an editorial

Plants possess a dynamic and multilayered immune system to counteract a wide range of pathogens, including bacteria, fungi, viruses, and nematodes. These defenses encompass both constitutive barriers and induced responses. Upon pathogen attack, plants recognize conserved microbial signatures via PAMP-triggered immunity (PTI), which can be further enhanced by effector-triggered immunity (ETI) and systemic acquired resistance (SAR). Key signaling molecules, salicylic acid, jasmonic acid, ethylene, reactive oxygen species, and nitric oxide, coordinate these defenses. The special issue “Plant Immunity and Resistance Mechanisms” in Physiological and Molecular Plant Pathology presents cutting-edge research covering molecular screening, gene expression, induced resistance, biocontrol, microbiome engineering, and pathogen characterization. Highlights include the identification of resistance loci in major crops, the role of transcription factors like WRKY and trihelix proteins, and transcriptomic profiling during host-pathogen interactions. Several studies demonstrated enhanced resistance through induced metabolic pathways, bioelicitors, and beneficial microbes such as Trichoderma asperellum and Beauveria bassiana. Investigations also revealed how antioxidant defense and partial resistance mitigate oxidative damage during infection. Pathogen-focused research unraveled virulence factors and host adaptation mechanisms, offering molecular targets for sustainable disease management. Collectively, these findings provide comprehensive insights into the physiological and molecular basis of plant immunity and support the development of durable, eco-friendly crop protection strategies.