Salicylic acid (SA) has long been known to be essential for basal defense and systemic acquired resistance (SAR). N-Hydroxypipecolic acid (NHP), a recently discovered plant metabolite, also plays a key role in SAR and to a lesser extent in basal resistance. Following pathogen infection, levels of both compounds are dramatically increased. Analysis of SA- or SAR-deficient mutants has uncovered how SA and NHP are biosynthesized. The completion of the SA and NHP biosynthetic pathways in Arabidopsis allowed better understanding of how they are regulated. In this review, we discuss recent progress on SA and NHP biosynthesis and their regulation in plant immunity.

水杨酸（SA）长期以来一直被认为是基础防御和全身性获得性抵抗（SAR）必不可少的。N-羟基哌酸（NHP）是一种最近发现的植物代谢产物，在SAR中也起着关键作用，而对基础抗性的作用较小。病原体感染后，两种化合物的水平都急剧增加。对SA缺失或SAR缺失的突变体的分析发现了SA和NHP是如何生物合成的。拟南芥中SA和NHP生物合成途径的完成使人们能够更好地了解它们的调控方式。在这篇综述中，我们讨论了SA和NHP生物合成的最新进展及其在植物免疫中的调控。