Großkinsky Dominik K, Molin Eva M, Bosetto Federico, Edelsbrunner Kerstin, Oravec Michal, Večeřová Kristýna, Tříska Jan, Roitsch Thomas
AIT Austrian Institute of Technology, Center for Health and Bioresources, Bioresources Unit, Tulln a. d. Donau, Austria.
Department of Plant and Environmental Sciences, University of Copenhagen, Taastrup, Denmark.
Physiol Plant. 2025 Jan-Feb;177(1):e70028. doi: 10.1111/ppl.70028.
The classic plant growth-promoting phytohormone cytokinin has been identified and established as a mediator of pathogen resistance in different plant species. However, the resistance effect of structurally different cytokinins appears to vary and may regulate diverse mechanisms to establish resistance. Hence, we comparatively analysed the impact of six different adenine- and phenylurea-type cytokinins on the well-established pathosystem Nicotiana tabacum-Pseudomonas syringae. The efficiency of resistance effects was evaluated based on impacts on the host plant defence response by scoring infection symptoms and the direct impact on the pathogen by assessment of proliferation in planta. To identify common and cytokinin-specific components involved in resistance effects, transcriptome profiling and targeted metabolomics were conducted in leaves treated with the different cytokinins. We observed clearly different potentials of the tested cytokinins in either suppressing infection symptoms or pathogen proliferation. Gene regulation and metabolite analyses revealed cytokinin-type specific impacts on defence components, such as salicylic acid and related signalling, expression of PR proteins, and regulation of specialised metabolism. Cytokinins also strongly affected plant cell physiological parameters, such as a remarkable decrease in amino acid pools. Hence, this study provides comparative information on the efficiency of diverse cytokinins in mediating resistance in one well-studied pathosystem and insights into the specific regulation of resistance effects mediated by different cytokinin molecules. This is particularly relevant for studies on the function of cytokinins or other phytohormones and compounds interacting with cytokinin activities in the context of pathogen infections and other stress scenarios, considering the diverse cytokinins present in plants.
经典的促进植物生长的植物激素细胞分裂素已被鉴定并确立为不同植物物种中病原体抗性的介导因子。然而，结构不同的细胞分裂素的抗性效应似乎有所不同，可能通过调节多种机制来建立抗性。因此，我们比较分析了六种不同的腺嘌呤型和苯基脲型细胞分裂素对成熟的烟草-丁香假单胞菌病理系统的影响。基于对宿主植物防御反应的影响（通过对感染症状评分）以及对病原体在植物体内增殖的评估来直接影响病原体，对抗性效应的效率进行了评估。为了确定参与抗性效应的共同和细胞分裂素特异性成分，在用不同细胞分裂素处理的叶片中进行了转录组分析和靶向代谢组学研究。我们观察到，所测试的细胞分裂素在抑制感染症状或病原体增殖方面具有明显不同的潜力。基因调控和代谢物分析揭示了细胞分裂素类型对防御成分的特异性影响，如水杨酸及相关信号传导、病程相关蛋白的表达以及特殊代谢的调控。细胞分裂素还强烈影响植物细胞生理参数，如氨基酸池显著减少。因此，本研究提供了关于多种细胞分裂素在一个深入研究的病理系统中介导抗性的效率的比较信息，并深入了解了不同细胞分裂素分子介导的抗性效应的特异性调控。考虑到植物中存在多种细胞分裂素，这对于在病原体感染和其他胁迫情况下细胞分裂素或其他植物激素以及与细胞分裂素活性相互作用的化合物的功能研究尤为重要。
