Sakurai Nozomu, Mardani-Korrani Hossein, Nakayasu Masaru, Matsuda Kazuhiko, Ochiai Kumiko, Kobayashi Masaru, Tahara Yusuke, Onodera Takeshi, Aoki Yuichi, Motobayashi Takashi, Komatsuzaki Masakazu, Ihara Makoto, Shibata Daisuke, Fujii Yoshiharu, Sugiyama Akifumi
Bioinformation and DDBJ Center, National Institute of Genetics, Mishima, Japan.
Kazusa DNA Research Institute, Kisarazu, Japan.
Front Genet. 2020 Feb 24;11:114. doi: 10.3389/fgene.2020.00114. eCollection 2020.
Inter-organismal communications below ground, such as plant-microbe interactions in the rhizosphere, affect plant growth. Metabolites are shown to play important roles in biological communication, but there still remain a large number of metabolites in soil to be uncovered. Metabolomics, a technique for the comprehensive analysis of metabolites in samples, may uncover the molecules that intermediate these interactions. We conducted a multivariate analysis using liquid chromatography (LC)-mass spectrometry (MS)-based untargeted metabolomics in several soil samples and also targeted metabolome analysis for the identification of the candidate compounds in soil. We identified okaramine A, B, and C in the rhizosphere soil of hairy vetch. Okaramines are indole alkaloids first identified in soybean pulp () inoculated with AK-40 and are insecticidal. Okaramine B was detected in the rhizosphere from an open field growing hairy vetch. Okaramine B was also detected in both bulk and rhizosphere soils of soybean grown following hairy vetch, but not detected in soils of soybean without hairy vetch growth. These results suggested that okaramines might be involved in indirect defense of plants against insects. To our knowledge, this is the first report of okaramines in the natural environment. Untargeted and targeted metabolomics would be useful to uncover the chemistry of the rhizosphere.
地下的生物体间通讯，例如根际中的植物 - 微生物相互作用，会影响植物生长。已表明代谢物在生物通讯中发挥重要作用，但土壤中仍有大量代谢物有待发现。代谢组学是一种用于全面分析样品中代谢物的技术，它可能会揭示介导这些相互作用的分子。我们使用基于液相色谱（LC）-质谱（MS）的非靶向代谢组学对多个土壤样品进行了多变量分析，并进行了靶向代谢组分析以鉴定土壤中的候选化合物。我们在毛苕子的根际土壤中鉴定出了冈田胺A、B和C。冈田胺是首次在接种了AK - 40的大豆浆中鉴定出的吲哚生物碱，具有杀虫作用。在种植毛苕子的田间根际中检测到了冈田胺B。在毛苕子后茬种植的大豆的块状土壤和根际土壤中也检测到了冈田胺B，但在未种植毛苕子的大豆土壤中未检测到。这些结果表明，冈田胺可能参与植物对昆虫的间接防御。据我们所知，这是冈田胺在自然环境中的首次报道。非靶向和靶向代谢组学将有助于揭示根际的化学性质。
