USDA-ARS Forage Seed Production Research Unit, Corvallis, Oregon, United States of America.
Department of Crop and Soil Sciences, Oregon State University, Corvallis, Oregon, United States of America.
PLoS One. 2018 Jul 10;13(7):e0200481. doi: 10.1371/journal.pone.0200481. eCollection 2018.
The oxyvinylglycine 4-formylaminooxyvinylglycine (FVG) arrests the germination of weedy grasses and inhibits the growth of the bacterial plant pathogen Erwinia amylovora. Both biological and analytical methods have previously been used to detect the presence of FVG in crude and extracted culture filtrates of several Pseudomonas fluorescens strains. Although a combination of these techniques is adequate to detect FVG, none is amenable to high-throughput analysis. Likewise, filtrates often contain complex metabolite mixtures that prevent the detection of FVG using established chromatographic techniques. Here, we report the development of a new method that directly detects FVG in crude filtrates using laser ablation electrospray ionization-mass spectrometry (LAESI-MS). This approach overcomes limitations with our existing methodology and allows for the rapid analysis of complex crude culture filtrates. To validate the utility of the LAESI-MS method, we examined crude filtrates from Pantoea ananatis BRT175 and found that this strain also produces FVG. These findings are consistent with the antimicrobial activity of P. ananatis BRT175 and indicate that the spectrum of bacteria that produce FVG stretches beyond rhizosphere-associated Pseudomonas fluorescens.
氧乙烯基甘氨酸 4-甲酰氨基氧乙烯基甘氨酸（FVG）能阻止杂草种子的发芽，并抑制细菌病原体梨火疫病菌（Erwinia amylovora）的生长。先前曾使用生物和分析方法来检测几种荧光假单胞菌菌株的粗提和提取培养滤液中 FVG 的存在。尽管这些技术的组合足以检测到 FVG，但没有一种方法适用于高通量分析。同样，滤液中通常含有复杂的代谢物混合物，这使得使用既定的色谱技术无法检测到 FVG。在这里，我们报告了一种新方法的开发，该方法使用激光烧蚀电喷雾电离质谱（LAESI-MS）直接检测粗滤液中的 FVG。这种方法克服了我们现有方法的局限性，并允许对复杂的粗培养滤液进行快速分析。为了验证 LAESI-MS 方法的实用性，我们检查了 Pantoea ananatis BRT175 的粗滤物，并发现该菌株也产生 FVG。这些发现与 P.ananatis BRT175 的抑菌活性一致，并表明产生 FVG 的细菌谱超出了根际相关的荧光假单胞菌。
