Answer:
Salicylic acid
Step-by-step explanation:
Salicylic acid is a plant hormone that is essential for a variety of biological parameters, including defence for a plant. There have been many advances in SA-mediated biosynthesis, transport, perception, and signaling over the past two decades. These data show that AS is crucial in local and systemic defensive responses. One such SA-dependent response is systemic acquired resistance (SAR). is a long-distance communication system that provides broad spectrum and long-term resistance to secondary infections throughout the plant. Because of this distinctive property, SAR is a highly sought after trait in agricultural production.This article describes recent developments of the SA function in SAR and analyzes how it connects to other SAR inductors.