Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, United States.
Department of Plant Pathology, University of Kentucky, Lexington, KY 40546, United States.
Curr Opin Virol. 2020 Jun;42:53-57. doi: 10.1016/j.coviro.2020.05.008. Epub 2020 Jun 13.
The small phenolic compound salicylic acid (SA) is a phytohormone that regulates many biological processes, although it is most well-known for its role in plant defense. SA is an important regulator of systemic acquired resistance (SAR), a type of systemic immunity that protects uninfected parts of the plant against secondary infections by a broad spectrum of pathogens. SAR involves the generation of mobile signal(s) at the primary infection site, which translocate to distal uninfected portions and activate systemic disease resistance. Although, SA was considered to not constitute the mobile SAR signal, it is preferentially transported from pathogen-infected to uninfected parts via the apoplast. Further investigations have revealed that distal transport of SA is indeed essential for SAR. The apoplastic SA transport is regulated by the transpirational pull and partitioning of SA between the symplast and cuticle.
小酚类化合物水杨酸（SA）是一种植物激素，调节许多生物过程，尽管它最著名的作用是在植物防御中。SA 是系统获得性抗性（SAR）的重要调节剂，SAR 是一种系统性免疫，可保护植物未感染部分免受广谱病原体的二次感染。SAR 涉及在原发性感染部位产生移动信号（s），这些信号转移到远端未感染部分并激活全身性疾病抗性。尽管如此，SA 被认为不构成移动的 SAR 信号，但它通过质外体优先从受病原体感染的部位运输到未感染的部位。进一步的研究表明，SA 的远端运输对 SAR 确实至关重要。质外体 SA 运输受蒸腾拉力调节，SA 在质外体和角质层之间分配。
