Corso Gabrielle, Triplett Lindsay R, Gage Daniel J
Department of Molecular and Cell Biology, The University of Connecticut, Storrs, Connecticut, USA.
Department of Environmental Science, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, USA.
mBio. 2025 Jul 9;16(7):e0084825. doi: 10.1128/mbio.00848-25. Epub 2025 May 30.
Soil protists are increasingly recognized as common members of complex communities that associate with plant root systems, though their contributions to these communities and to the plant host remain obscure. Members of Clade-U/Group-TE are cosmopolitan soil protists and often among the most abundant protists associated with plant roots. Here, we describe the isolation, culturing, and characterization of , a member of the previously uncultured Clade-U/Group-TE branch of the order Glissomonadida. grew readily when provided bacteriophage lysate as a food source. This allowed us to grow large numbers of the organisms from single-cell isolates and provided ideal conditions for following transitions from one morphology to another. , like most glissomonads, has a small, flagellated gliding form, but it also displays a wide range of other morphologies, including a crawling form, small and large trophozoites with multiple long filopodia, small and large resting cysts, and clusters of large dividing cells, and cannibalistic feeding behaviors. Given the small size of most glissomonads, it may be that other members of this important group, known from environmental surveys but currently uncultured, might also be readily grown on bacteriophage lysates. In addition, given an abundant food source and clear viewing by microscopy, glissomonads and other small protists may be found to have life cycles and behaviors that are more complex than is currently appreciated.IMPORTANCEProtists from the Clade-U/Group-TE cluster of glissomonads are widespread and abundant colonizers of plant roots. Despite being known for over 30 years, they have remained uncultured. We show that these protists can be easily cultured using an unusual food source, viral lysates of bacteria. This culturing method allows growth of high numbers of these organisms and reveals that they have an unexpectedly complex lifecycle that includes community feeding and cannibalism. Some other currently unculturable protists can perhaps be grown with these methods, and many of these may also show unexpectedly complex lifecycles. The growth of eukaryotes on virus lysates raises the possibility that viruses in soil may directly contribute to the growth (and not just death) of eukaryotes in soil and root-associated communities.
土壤原生生物越来越被视为与植物根系相关的复杂群落中的常见成员，尽管它们对这些群落和植物宿主的贡献仍不清楚。进化枝U/TE组的成员是世界性的土壤原生生物，通常是与植物根系相关的最丰富的原生生物之一。在这里，我们描述了滑行目进化枝U/TE组中一个以前未培养的成员的分离、培养和特征。当提供噬菌体裂解物作为食物来源时，它很容易生长。这使我们能够从单细胞分离物中培养大量的这种生物，并为观察从一种形态到另一种形态的转变提供了理想条件。与大多数滑行目生物一样，它有一个小的、有鞭毛的滑行形态，但它也表现出多种其他形态，包括爬行形态、有多个长丝状伪足的小和大滋养体、小和大的休眠囊肿，以及大量分裂细胞的聚集体，还有同类相食的摄食行为。鉴于大多数滑行目生物体型较小，可能这个重要类群中其他从环境调查中已知但目前尚未培养的成员，也可以很容易地在噬菌体裂解物上生长。此外，鉴于有丰富的食物来源且通过显微镜可以清晰观察，可能会发现滑行目生物和其他小型原生生物具有比目前所认识到的更复杂的生命周期和行为。
滑行目进化枝U/TE组的原生生物是植物根系广泛且丰富的定殖者。尽管已被知晓30多年，但它们仍未被培养。我们表明，这些原生生物可以使用一种不寻常的食物来源——细菌的病毒裂解物——轻松培养。这种培养方法能够大量培养这些生物，并揭示它们具有意想不到的复杂生命周期，包括群体摄食和同类相食。一些其他目前无法培养的原生生物也许可以用这些方法培养，而且其中许多可能也表现出意想不到的复杂生命周期。真核生物在病毒裂解物上生长增加了土壤中的病毒可能直接促进土壤和与根系相关群落中真核生物生长（而不仅仅是死亡）的可能性。
