SYSTEMIC ACQUIRED RESISTANCE

TLDR

SAR provides quantitative protection against a broad spectrum of microorganisms, analogous to mammalian immunization, though mechanisms differ. The study examines SAR in plants against insect and pathogenic invaders. SAR is mediated by lignification, structural barriers, pathogenesis‑related proteins, salicylic acid signaling, and is influenced by systemin, ethylene, jasmonates, electrical signals, and chemical activators (inorganic, natural, synthetic). The paper lists plants that exhibit SAR and induced systemic resistance.

Abstract

This paper examines induced resistance (SAR) in plants against various insect and pathogenic invaders. SAR confers quantitative protection against a broad spectrum of microorganisms in a manner comparable to immunization in mammals, although the underlying mechanisms differ. Discussed here are the molecular events underlying SAR: the mechanisms involved in SAR, including lignification and other structural barriers, pathogenesis-related proteins and their expression, and the signals for SAR including salicylic acid. Recent findings on the biological role of systemin, ethylene, jasmonates, and electrical signals are reviewed. Chemical activators of SAR comprise inorganic compounds, natural compounds, and synthetic compounds. Plants known to exhibit SAR and induced systemic resistance are listed.