Induced Systemic Resistance in Plants: Mechanisms and Agricultural Significance

Abstract

Induced Systemic Resistance (ISR) is a plant immune phenomenon where prior exposure to beneficial microbes, elicitors or mild stress primes distant tissues for faster and stronger defense against subsequent pathogens and pests. ISR operates through complex signaling networks (primarily jasmonic acid/ethylene pathways, with crosstalk with salicylic acid-mediated routes), modulation of reactive oxygen species, and elevated activities of defense enzymes and PR (pathogenesis-related) genes. Harnessing ISR in Bundelkhand — a semi-arid, pulse-dominant region of Uttar Pradesh — offers a sustainable strategy to reduce chemical inputs, improve pulse yields and manage soil-borne pathogens by using locally adapted PGPR and Trichoderma isolates. This paper reviews mechanisms, presents region-relevant evidence, outlines methods for field-level ISR evaluation, shows representative results (rhizobacterial diversity and Trichoderma antifungal activity), and discusses implications for agronomy and policy in Bundelkhand.