Salicylic acid (SA) is a key plant hormone required for establishing resistance to many pathogens. SA biosynthesis involves two main metabolic pathways with multiple steps: the isochorismate and the phenylalanine ammonia-lyase pathways. Transcriptional regulations of SA biosynthesis are important for fine-tuning SA level in plants. We highlight here recent discoveries on SA biosynthesis and transcriptional regulations of SA biosynthesis. In addition, SA perception by NPR proteins is important to fulfil its function as a defense hormone. We highlight recent work to give a full picture of how NPR proteins support the role of SA in plant immunity. We also discuss challenges and potential opportunities for future research and application related to the functions of SA in plants.

水杨酸（SA）是对多种病原体产生抗性所需的关键植物激素。SA的生物合成涉及两个主要的代谢途径，分多个步骤：等渗酸途径和苯丙氨酸解氨酶途径。SA生物合成的转录调控对于微调植物中的SA水平很重要。我们在这里重点介绍SA生物合成的最新发现和SA生物合成的转录调控。此外，NPR蛋白对SA的感知对于实现其作为防御激素的功能也很重要。我们重点介绍最近的工作，以全面了解NPR蛋白如何支持SA在植物免疫中的作用。我们还将讨论与植物SA功能相关的未来研究和应用所面临的挑战和潜在机遇。