Zanzarin Daniele Maria, Hernandes Carolina Parcero, Leme Luiza Mariano, Silva Evandro, Porto Carla, Martin do Prado Rodolpho, Meyer Mauricio C, Favoreto Luciany, Nunes Estela de Oliveira, Pilau Eduardo Jorge
Laboratory of Biomolecules and Mass Spectrometry, Department of Chemistry, State University of Maringá, Maringá, PR, Brazil.
Graduate Program in Cell Biology, State University of Maringá, Maringá, PR, Brazil.
Rapid Commun Mass Spectrom. 2020 Sep;34 Suppl 3:e8655. doi: 10.1002/rcm.8655. Epub 2020 Feb 11.
The nematode Aphelenchoides besseyi is the causal agent of green stem and foliar retention, a soybean disease recently described in Brazil. This condition can reduce soybean yield by up to 100%. However, little is known about chemical interactions between the plant and pathogen. Therefore, this work aimed to investigate metabolites from healthy soybean roots and from soybean roots that were inoculated with A. besseyi.
A. besseyi were multiplied in vitro with Fusarium sp. colonies in Petri dishes for 25 days, and were axenically inoculated into hydroponics healthy soybean plants. The metabolites were extracted from the roots of healthy and A. besseyi-infected plants 16 days post-inoculation. These extracts were analyzed using an untargeted metabolomic method with an ultra-high-performance liquid chromatography/electrospray ionization /tandem mass spectrometry (UHPLC/ESI-MS/MS) and molecular networking approach.
Roots from infected plants showed morphological alterations such as shrinkage, darkening, and arching. Similarly, they also showed an increased presence of flavonoids, compared with healthy roots. Compounds such as neobavaisoflavone, glycitin, genistin, and genistein were putatively identified and had greater intensity in inoculated roots. These compounds are linked to the defensive mechanisms in plants against nematodes. Moreover, coumaric acid, also exclusively putatively identified in inoculated roots, shows activity related to inhibition of root growth.
Liquid chromatography, mass spectrometry, and molecular networking approaches proved to be a powerful tool for the metabolomic study of GSFR. This study showed metabolomics differences of protective substances in the roots, evidencing a quick response of the plant to the attack of A. besseyi.
线虫贝西滑刃线虫是绿茎和叶片滞留病的病原体，这是巴西最近发现的一种大豆病害。这种情况可使大豆产量降低多达100%。然而，关于植物与病原体之间的化学相互作用知之甚少。因此，本研究旨在调查健康大豆根以及接种了贝西滑刃线虫的大豆根中的代谢物。
在培养皿中，将贝西滑刃线虫与镰刀菌菌落一起体外培养25天，然后无菌接种到水培健康大豆植株中。接种16天后，从健康植株和感染贝西滑刃线虫的植株的根中提取代谢物。使用超高效液相色谱/电喷雾电离/串联质谱（UHPLC/ESI-MS/MS）的非靶向代谢组学方法和分子网络方法对这些提取物进行分析。
受感染植株的根表现出形态改变，如萎缩、变黑和弯曲。同样，与健康根相比，它们还表现出类黄酮含量增加。新补骨脂异黄酮、大豆黄素、染料木苷和染料木黄酮等化合物被初步鉴定，且在接种根中的强度更大。这些化合物与植物对线虫的防御机制有关。此外，香豆酸也仅在接种根中被初步鉴定，显示出与抑制根生长相关的活性。
液相色谱、质谱和分子网络方法被证明是研究绿茎和叶片滞留病根代谢组学的有力工具。本研究显示了根中保护物质的代谢组学差异，证明了植物对贝西滑刃线虫攻击的快速反应。
