Induced Systemic Resistance in Plant

Abstract

Plants respond to localized attacks by herbivores or various pathogens by producing compounds that reduce or prevent further damage by these threats and the spread of infection. These responses occur both at the site of the initial attack (local response) and in distant, unaffected parts of the plant (systemic response). Systemic resistance is classified into two types: Induced Systemic Resistance (ISR), which is activated in plants through inoculation with beneficial soil-dwelling microorganisms or their plant growth-regulating metabolites, including Plant Growth-Promoting Bacteria (PGPB) and Plant Growth-Promoting Fungi (PGPF), in addition to certain synthetic or biogenic chemical compounds. This type of resistance relies on the jasmonic acid (JA) and ethylene (ET) signaling pathways and typically leads to the production of non-specific defense proteins.

The other type is Systemic Acquired Resistance (SAR), which is triggered following pathogen infection. SAR provides protection not only against the current infection but also against future attacks. It is mediated through the salicylic acid (SA) signaling pathway and results in the accumulation of specialized proteins that act against a broad spectrum of pathogens.

This study aims to elucidate the different types of systemic resistance and their critical role in protecting plants from various diseases, with particular emphasis on the importance of hormone-mediated signaling pathways.