Jasmonate-ethylene (JA/ET) signaling – metabolic defense system in the integrative model of plant immunity against phytophagous insects

Every year, humanity loses up to 40% of crop yields due to pests and plant diseases. This accounts for over USD 220 billion in economic losses, with approximately USD 70 billion caused by invasive insects. Plant responses to damage by arthropod herbivores represent a complex form of biotic stress that combines mechanical injury, danger signals, and ho r monal interactions. This article proposes a systemic concept that explains how the JA/ET-dominant immune mode is int e grated into a multistable plant immune defense network. Local tissue damage activates DAMP and HAMP signaling, which triggers Ca²⁺–ROS–MAPK cascades and the synthesis of jasmonic acid and ethylene. These pathways interact with aut o phagy, ROS/NO homeostasis, and the antioxidant system, forming feedback-regulated loops that coordinate programmed cell death (PCD) with systemic tolerance. The JA/ET branch is viewed as an adaptive configuration of plant immunity that provides energy-efficient, non-specific resistance of the ISR (induced systemic resistance) type. The integration of JA/ET signaling with autophagic and redox-regulatory circuits explains how a plant converts local damage into systemic resilience. Damage to plants caused by phytophagous insects integrates both local and systemic levels of immunity into a unified, d y namic defense system represented by the JA/ET-dominant immune mode. This mode combines molecular signaling, met a bolic control, and holistic plant adaptation to herbivores. The integrative multistate model of plant immunity introduces a new level of understanding of natural defense mechanisms and provides a foundation for breeding highly resistant crop varieties of the future. It also forms a scientific basis for the development of fourth-generation bioproducts that activate the plant’s natural immunity ( either independently or in combination with pesticides ) . The use of such integrated immune strat e gies has the potential to reduce crop losses from pests and diseases by 10–20%, which is equivalent to a global economic savings of USD 7–14 billion annually. This approach lowers the risk of resistance development in harmful organisms and promotes ecological sustainability in agroecosystems.