Skeletonemacostatum,主要居住在沿海生态系统中的世界性硅藻,与异养细菌表现出通常密切但可变的关系。预计地表海水温度的升高将极大地影响S.costatum的生存能力和生态动态。有可能改变它与细菌的关系.然而,目前尚不清楚高温会在多大程度上改变这些关系。这里,随着共培养温度从20°C增加到25°C,无菌S.costatum和天然海水细菌之间的关系经历了从共生到拮抗的戏剧性转变。共现网络表明温度升高后,S.costatum与细菌群落之间相互作用的复杂性显着增加。尤其是黄杆菌科细菌,暗示它们在较高温度下消除S.costatum的潜在作用。此外,a黄杆菌科分离物,即MS1被鉴定为Tamlana属,在25°C下从共培养系统中分离。MS1具有显着的消除S.costatum的能力,25°C时的死亡率从48小时的30.2%稳步上升到120小时的92.4%。它在20°C下在一定程度上促进藻类生长。这些结果表明,升高的温度可促进MS1与S.costatum从共生转变为拮抗作用。根据比较基因组学分析,MS1生活方式的变化归因于高温下MS1的滑动运动和附着增加,使其能够通过与藻类直接接触发挥杀藻作用。这项调查提供了对未来变暖的海洋生态系统中浮游植物与细菌之间相互作用的深入了解。
目的:海洋变暖深刻影响浮游植物和细菌的生长和代谢,从而极大地重塑了它们的相互作用。先前的研究表明,变暖可以改变细菌的生活方式,从共生到与浮游植物的拮抗,但潜在的机制仍不清楚。在这项研究中,我们发现高温能促进Tamlanasp.MS1与骨骼粘合力,通过直接接触导致藻类裂解,证明了随着温度的升高,生活方式从相互主义到对抗主义的转变。此外,MS1的滑翔运动似乎在介导其生活方式的转变中起着关键作用。这些发现不仅促进了我们对海洋变暖下浮游植物与细菌关系的理解,而且为预测变暖对浮游植物碳固存的影响提供了有价值的见解。
Skeletonema costatum, a cosmopolitan diatom primarily inhabiting coastal ecosystems, exhibits a typically close yet variable relationship with heterotrophic bacteria. The increasing temperature of surface seawater is expected to substantially affect the viability and ecological dynamics of S. costatum, potentially altering its relationship with bacteria. However, it remains unclear to what extent the elevated temperature could change these relationships. Here, the relationship between axenic S. costatum and natural seawater bacteria underwent a dramatic shift from mutualism to antagonism as the co-culture temperature increased from 20°C to 25°C. The co-occurrence network indicated significantly increased complexity of interaction between S. costatum and bacteria community after temperature elevation, especially with Flavobacteriaceae, implying their potential role in eliminating S. costatum under higher temperatures. Additionally, a Flavobacteriaceae isolate, namely MS1 identified as Tamlana genus, was isolated from the co-culture system at 25°C. MS1 had a remarkable ability to eliminate S. costatum, with the mortality rate at 25°C steadily rising from 30.2% at 48 h to 92.4% at 120 h. However, it promoted algal growth to some extent at 20°C. These results demonstrated that increased temperature promotes MS1 shifts from mutualism to antagonism with S. costatum. According to the comparative genomics analysis, changes in the lifestyle of MS1 were attributed to the increased gliding motility and attachment of MS1 under elevated temperature, enabling it to exert an algicidal effect through direct contact with alga. This investigation provided an advanced understanding of interactions between phytoplankton and bacteria in future warming oceanic ecosystems.
OBJECTIVE: Ocean warming profoundly influences the growth and metabolism of phytoplankton and bacteria, thereby significantly reshaping their interactions. Previous studies have shown that warming can change bacterial lifestyle from mutualism to antagonism with phytoplankton, but the underlying mechanism remains unclear. In this study, we found that high temperature promotes Tamlana sp. MS1 adhesion to Skeletonema costatum, leading to algal lysis through direct contact, demonstrating a transition in lifestyle from mutualism to antagonism with increasing temperature. Furthermore, the gliding motility of MS1 appears to be pivotal in mediating the transition of its lifestyle. These findings not only advance our understanding of the phytoplankton-bacteria relationship under ocean warming but also offer valuable insights for predicting the impact of warming on phytoplankton carbon sequestration.