来自美国康奈尔大学的研究团队利用LC-MS与同位素示踪技术确证了植物可以代谢处理来自于线虫产生的ascr#18，证明了线虫信息素的植物代谢介导植物与线虫的相互作用。
为了确定植物是否可以代谢处理来自于线虫产生的ascr#18，研究团队通过高分辨液相色谱-质谱联用仪（LC-MS）对无菌状态下ascr#18处理的双子叶番茄、拟南芥和单子叶小麦植株进行代谢物LC-MS分析。
Abstract
Microorganisms and nematodes in the rhizosphere profoundly impact plant health, and small-molecule signaling is presumed to play a central role in plant rhizosphere interactions. However, the nature of the signals and underlying mechanisms are poorly understood. Here we show that the ascaroside ascr#18, a pheromone secreted by plant-parasitic nematodes, is metabolized by plants to generate chemical signals that repel nematodes and reduce infection. Comparative metabolomics of plant tissues and excretions revealed that ascr#18 is converted into shorter side-chained ascarosides that confer repellency. An Arabidopsis mutant defective in two peroxisomal acyl-CoA oxidases does not metabolize ascr#18 and does not repel nematodes, indicating that plants, like nematodes, employ conserved peroxisomal β-oxidation to edit ascarosides and change their message. Our results suggest that plant-editing of nematode pheromones serves as a defense mechanism that acts in parallel to conventional pattern-triggered immunity, demonstrating that plants may actively manipulate chemical signaling of soil organisms.
Introduction
Immune responses to pathogen attack in plants and animals are triggered in part by detection of pathogen-associated molecular patterns (PAMPs) by specific extra- and intra-cellular sensors1,2,3,4 (Fig. 1a). This includes evolutionarily conserved macromolecules specific to different classes of pathogens, for example, flagellin and peptidoglycan for bacteria or chitin for fungi5,6,7. Activation of innate immunity resulting from recognition of these foreign (non-self) macromolecules is generally termed pattern-triggered immunity (PTI). In the case of parasitic nematodes, a conserved family of pheromones, the ascarosides, similarly functions as a small-molecule signature that elicits plant immune responses8.
更多查看点击下载查看
文献来源：
https://doi.org/10.1038/s41467-019-14104-2