multiple defense layers in plant-pathogen interactions

Biotic stresses always impact the yield of plants, and understanding the interaction between plants and pathogens is crucial for disease control. plants’ defense mechanisms against pathogens have various complex layers. as pathogens evolve to have more complicated and efficient effector systems during plant-pathogen coevolution, plants develop more sophisticated defense systems. the complexity of plant defense systems can be explored at different levels, including reactive oxygen species (ros) scavenging, changes in transcription factor (tfs) expression, increased activity of prs, and accumulation of lignin. additionally, systemic acquired resistance (sar) and induced systemic resistance (isr) induction pathways play a significant role in how plants respond to biotic stresses. erf and npr1 genes activate sar and isr pathways. various protein families associated with the plant defense system, such as  pathogenesis-related proteins (prs), regulate a wide range of responses to pathogens, hindering pathogen penetration. the accumulation of certain metabolites, like lignin, helps prevent pathogen penetration and the spread of disease in plants, serving as part of the defense system. this review provides a brief overview of the diverse and essential layers of the plant’s defense system against pathogens, aiding in the understanding of plant-pathogen interactions.