浮游植物开花期间溶解有机物的产生和异养原核生物的消耗促进了海洋碳生物地球化学循环。尽管原核病毒可能会影响这一过程,他们在开花期间的动态还没有完全理解。这里,我们研究了水华形成浮游植物的分类学差异对原核生物及其病毒的影响。我们分析了从分类学上不同的浮游植物中添加溶解的胞内部分的沿海原核生物群落和病毒的动力学,硅藻Chaetocerossp.(CIF)和raphidophycean藻类Heterosigmaakashiwo(HIF),使用微观实验。核糖体RNA基因扩增子和病毒宏基因组分析显示,特定的原核生物和原核病毒在CIF或HIF中特异性增加,表明水华形成浮游植物的分类学差异不仅促进了原核生物群落的动态,而且促进了原核生物病毒的动态。此外,将我们的微观实验与公开的环境数据挖掘相结合,我们确定了已知和新的可能的宿主病毒对。特别是,与浮游植物有机质相关的原核生物的生长,例如拟杆菌(杆菌属和NS9海洋组),弧菌属。,和红杆菌(Nereida和Planktomarina),伴随着预测感染拟杆菌的病毒的增加,弧菌,和红杆菌,分别。总的来说,我们的发现表明,水华形成物种的变化可以伴随着一组特定的原核生物及其病毒的增加,并且阐明了特定浮游植物之间的三方关系,原核生物,和原核病毒提高了我们对沿海生物地球化学循环的理解。重要海洋浮游植物水华期间的初级生产和异养原核生物对产生的有机物的消耗极大地促进了沿海生物地球化学循环。虽然这些异养原核生物的活动可能受到病毒感染的影响,他们的病毒在开花期间的动态还没有完全理解。在这项研究中,我们通过实验证明了分类学上不同的水华形成浮游植物物种的细胞内部分,硅藻Chaetocerossp.和raphidophypean藻类Heterosigmaakashiwo,促进了分类学上不同的原核生物和原核病毒的生长。根据这些病毒的动态和预测宿主,我们成功地检测到已知的和新的可能的宿主病毒对与浮游植物物种有关。总之,我们认为水华浮游植物的演替会改变大量原核生物的组成,导致他们的病毒增加。病毒组成的这些变化,取决于水华形成的物种,会改变原核生物的动力学和代谢,影响水华的生物地球化学循环。
The production of dissolved organic matter during phytoplankton blooms and consumption by heterotrophic prokaryotes promote marine carbon biogeochemical cycling. Although prokaryotic viruses presumably affect this process, their dynamics during blooms are not fully understood. Here, we investigated the effects of taxonomic difference in bloom-forming phytoplankton on prokaryotes and their viruses. We analyzed the dynamics of coastal prokaryotic communities and viruses under the addition of dissolved intracellular fractions from taxonomically distinct phytoplankton, the diatom Chaetoceros sp. (CIF) and the raphidophycean alga Heterosigma akashiwo (HIF), using microcosm experiments. Ribosomal RNA gene amplicon and viral metagenomic analyses revealed that particular prokaryotes and prokaryotic viruses specifically increased in either CIF or HIF, indicating that taxonomic difference in bloom-forming phytoplankton promotes distinct dynamics of not only the prokaryotic community but also prokaryotic viruses. Furthermore, combining our microcosm experiments with publicly available environmental data mining, we identified both known and novel possible host-virus pairs. In particular, the growth of prokaryotes associating with phytoplanktonic organic matter, such as Bacteroidetes (Polaribacter and NS9 marine group), Vibrio spp., and Rhodobacteriales (Nereida and Planktomarina), was accompanied by an increase in viruses predicted to infect Bacteroidetes, Vibrio, and Rhodobacteriales, respectively. Collectively, our findings suggest that changes in bloom-forming species can be followed by an increase in a specific group of prokaryotes and their viruses and that elucidating these tripartite relationships among specific phytoplankton, prokaryotes, and prokaryotic viruses improves our understanding of coastal biogeochemical cycling in blooms.IMPORTANCEThe primary production during marine phytoplankton bloom and the consumption of the produced organic matter by heterotrophic prokaryotes significantly contribute to coastal biogeochemical cycles. While the activities of those heterotrophic prokaryotes are presumably affected by viral infection, the dynamics of their viruses during blooms are not fully understood. In this study, we experimentally demonstrated that intracellular fractions of taxonomically distinct bloom-forming phytoplankton species, the diatom Chaetoceros sp. and the raphidophycean alga Heterosigma akashiwo, promoted the growth of taxonomically different prokaryotes and prokaryotic viruses. Based on their dynamics and predicted hosts of those viruses, we succeeded in detecting already-known and novel possible host-virus pairs associating with either phytoplankton species. Altogether, we propose that the succession of bloom-forming phytoplankton would change the composition of the abundant prokaryotes, resulting in an increase in their viruses. These changes in viral composition, depending on bloom-forming species, would alter the dynamics and metabolism of prokaryotes, affecting biogeochemical cycling in blooms.