Department of Plant Pathology and Weed Research, Institute of Plant Protection, Agricultural Research Organization (ARO) - Volcani Institute, Rishon Lezion, Israel.
Department of Botany, Visva-Bharati Central University, Santiniketan, West Bengal, India.
Physiol Plant. 2024 May-Jun;176(3):e14399. doi: 10.1111/ppl.14399.
Salicylic acid (SA) is an important phytohormone, well-known for its regulatory role in shaping plant immune responses. In recent years, significant progress has been made in unravelling the molecular mechanisms underlying SA biosynthesis, perception, and downstream signalling cascades. Through the concerted efforts employing genetic, biochemical, and omics approaches, our understanding of SA-mediated defence responses has undergone remarkable expansion. In general, following SA biosynthesis through Avr effectors of the pathogens, newly synthesized SA undergoes various biochemical changes to achieve its active/inactive forms (e.g. methyl salicylate). The activated SA subsequently triggers signalling pathways associated with the perception of pathogen-derived signals, expression of defence genes, and induction of systemic acquired resistance (SAR) to tailor the intricate regulatory networks that coordinate plant immune responses. Nonetheless, the mechanistic understanding of SA-mediated plant immune regulation is currently limited because of its crosstalk with other signalling networks, which makes understanding this hormone signalling more challenging. This comprehensive review aims to provide an integrated overview of SA-mediated plant immunity, deriving current knowledge from diverse research outcomes. Through the integration of case studies, experimental evidence, and emerging trends, this review offers insights into the regulatory mechanisms governing SA-mediated immunity and signalling. Additionally, this review discusses the potential applications of SA-mediated defence strategies in crop improvement, disease management, and sustainable agricultural practices.
水杨酸（SA）是一种重要的植物激素，以其在调节植物免疫反应方面的作用而闻名。近年来，人们在揭示 SA 生物合成、感知和下游信号级联的分子机制方面取得了重大进展。通过遗传、生化和组学方法的协同作用，我们对 SA 介导的防御反应的理解有了显著的扩展。一般来说，在病原体的 Avr 效应子通过 SA 生物合成之后，新合成的 SA 会经历各种生化变化，以达到其活性/非活性形式（例如甲基水杨酸酯）。随后，激活的 SA 触发与病原体衍生信号感知、防御基因表达和系统获得性抗性（SAR）诱导相关的信号通路，以调整协调植物免疫反应的复杂调控网络。然而，由于 SA 与其他信号网络的相互作用，目前对 SA 介导的植物免疫调节的机制理解有限，这使得理解这种激素信号更加具有挑战性。本综述旨在从不同的研究结果中提供一个综合的关于 SA 介导的植物免疫的概述。通过案例研究、实验证据和新兴趋势的整合，本综述提供了对调控 SA 介导免疫和信号的机制的深入了解。此外，本综述还讨论了 SA 介导的防御策略在作物改良、疾病管理和可持续农业实践中的潜在应用。
