Department of Biology, Healthcare and Environment, Section of Plant Physiology, Faculty of Pharmacy and Food Sciences, Universitat de Barcelona, Barcelona, Spain.
Departamento de Biología, Bioquímica y Ciencias Naturales, Universitat Jaume I, Castelló de la Plana, Spain.
Plant Cell Environ. 2023 Dec;46(12):3949-3970. doi: 10.1111/pce.14706. Epub 2023 Aug 31.
Polyamines are small aliphatic polycations present in all living organisms. In plants, the most abundant polyamines are putrescine (Put), spermidine (Spd) and spermine (Spm). Polyamine levels change in response to different pathogens, including Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). However, the regulation of polyamine metabolism and their specific contributions to defence are not fully understood. Here we report that stimulation of Put biosynthesis by Pst DC3000 is dependent on coronatine (COR) perception and jasmonic acid (JA) signalling, independently of salicylic acid (SA). Conversely, lack of Spm in spermine synthase (spms) mutant stimulated galactolipids and JA biosynthesis, and JA signalling under basal conditions and during Pst DC3000 infection, whereas compromised SA-pathway activation and defence outputs through SA-JA antagonism. The dampening of SA responses correlated with COR and Pst DC3000-inducible deregulation of ANAC019 expression and its key SA-metabolism gene targets. Spm deficiency also led to enhanced disease resistance to the necrotrophic fungal pathogen Botrytis cinerea and stimulated endoplasmic reticulum (ER) stress signalling in response to Pst DC3000. Overall, our findings provide evidence for the integration of polyamine metabolism in JA- and SA-mediated defence responses, as well as the participation of Spm in buffering ER stress during defence.
多胺是存在于所有生物体中的小脂族聚阳离子。在植物中，最丰富的多胺是腐胺（Put）、亚精胺（Spd）和精胺（Spm）。多胺水平会响应不同的病原体而变化，包括丁香假单胞菌 pv.番茄 DC3000（Pst DC3000）。然而，多胺代谢的调节及其对防御的特定贡献尚未完全了解。在这里，我们报告说，Pst DC3000 刺激 Put 生物合成依赖于冠菌素（COR）感知和茉莉酸（JA）信号，而不依赖于水杨酸（SA）。相反，在 spermine synthase (spms) 突变体中缺乏精胺会刺激半乳糖脂和 JA 的生物合成，并在基础条件下和 Pst DC3000 感染期间刺激 JA 信号，而通过 SA-JA 拮抗作用削弱 SA 途径的激活和防御产物。SA 反应的减弱与 COR 和 Pst DC3000 诱导的 ANAC019 表达及其关键 SA 代谢基因靶标的失调有关。Spm 缺乏也导致对坏死真菌病原体 Botrytis cinerea 的抗病性增强，并在响应 Pst DC3000 时刺激内质网（ER）应激信号。总的来说，我们的研究结果为多胺代谢在 JA 和 SA 介导的防御反应中的整合提供了证据，以及 Spm 在防御过程中缓冲 ER 应激的参与。
