Plants possess a unique form of broad-spectrum long-distance immunity termed systemic acquired resistance (SAR). SAR involves the rapid generation of mobile signal(s) in response to localized microbial infection, which transport to the distal tissue and ‘prime’ them against future infections by related and unrelated pathogens. Several SAR-inducing chemicals that could be classified as the potential mobile signal have been identified. Many of these function in a bifurcate pathway with both branches being equally essential for SAR induction. This review reflects on the potential candidacy of the known SAR inducers as mobile signal(s) based on historical knowledge of the SAR signal and recent advances in the SAR signaling pathway.

植物具有称为系统获得性抗性（SAR）的独特形式的广谱远距离免疫。SAR涉及对局部微生物感染的响应，可快速生成移动信号，这些微生物会迁移到远端组织，并“灌注”它们以防将来受到相关和无关病原体的感染。已经确定了几种可以归类为潜在移动信号的SAR诱导化学物质。其中许多功能在分支路径中起作用，两个分支对于SAR诱导同样重要。这篇评论基于SAR信号的历史知识和SAR信号通路的最新进展，反映了已知SAR诱导物作为移动信号的潜在候选资格。