Ramírez Natalia, Vinchira-Villarraga Diana, Rabiey Mojgan, Sigurbjörnsdóttir Margrét Auður, Heidmarsson Starri, Vilhelmsson Oddur, Jackson Robert W
Department of Natural Resource Sciences, University of Akureyri, Akureyri, Iceland.
School of Biosciences and Birmingham Institute of Forest Research, University of Birmingham, Birmingham, UK.
Environ Microbiol. 2025 Mar;27(3):e70057. doi: 10.1111/1462-2920.70057.
The specific association of the potentially plant-pathogenic Pseudomonas syringae with Peltigera lichens raises questions about the factors driving this host specificity. To explore this, the metabolic profile of seven lichen species belonging to three genera (Cladonia, Peltigera and Stereocaulon) was analysed using LC-MSMS. In addition, we assessed the growth of P. syringae strains in media supplemented with extracts from each lichen species. This revealed that Peltigera exhibits lower metabolite richness compared to other genera, but shows a higher chemical investment in specific compounds. Growth kinetics showed comparable P. syringae growth across lichen-supplemented media, except for Cladonia arbuscula and Cladonia sp., where the former exhibited lower growth rates. Inhibition assays with lichen extracts showed no inhibition of P. syringae. The lichen metabolome is predominantly composed of lipids and organic acids. Furthermore, specific compounds, such as aminoglycosides, may facilitate P. syringae presence in Peltigera by inhibiting Bacillus subtilis and other antagonists. In addition, compounds absent in Peltigera, like anthracene, might serve as a carbon source inhibitor like Bacillus velezensis.
具有潜在植物致病性的丁香假单胞菌与地卷衣的特定关联引发了关于驱动这种宿主特异性的因素的问题。为了探究这一点，我们使用液相色谱-串联质谱法分析了三个属（石蕊属、地卷属和树花属）的七种地衣物种的代谢谱。此外，我们评估了丁香假单胞菌菌株在添加了每种地衣物种提取物的培养基中的生长情况。结果表明，与其他属相比，地卷属的代谢物丰富度较低，但在特定化合物上的化学投入较高。生长动力学表明，在添加地衣提取物的培养基中，丁香假单胞菌的生长情况相当，除了丛生石蕊和石蕊属的一个物种，前者的生长速率较低。用地衣提取物进行的抑制试验表明，其对丁香假单胞菌没有抑制作用。地衣代谢组主要由脂质和有机酸组成。此外，特定化合物，如氨基糖苷类，可能通过抑制枯草芽孢杆菌和其他拮抗剂来促进丁香假单胞菌在地卷属中的存在。此外，地卷属中不存在的化合物，如蒽，可能像贝莱斯芽孢杆菌一样作为碳源抑制剂。
