Final answer:
Systemic acquired resistance in plants is carried out by inducing a broad-spectrum defense response throughout the plant. This involves the activation of defense genes and the production of antimicrobial compounds.
Step-by-step explanation:
Systemic acquired resistance (SAR) in plants is carried out by inducing a broad-spectrum defense response throughout the plant. This is achieved through the activation of defense genes and the production of antimicrobial compounds.
For example, the plant hormone salicylic acid (SA) plays a crucial role in SAR establishment by activating defense genes and signaling pathways. Upon infection by a pathogen, SAR-inducing molecules like SA are produced and transported to systemic tissues, which prepares the plant for a faster and more efficient defense response in case of future pathogen attacks.