微塑料,无处不在的人为海洋污染物,代表了全球珊瑚礁生态系统中对珊瑚-共生菌科关系的潜在威胁。然而,聚苯乙烯微塑料(PS-MPs)对共生菌科的影响的潜在机制仍然知之甚少。在这项研究中,细胞学,生理,和三氧化二氮共生菌的微生物反应,一种代表性的共生虫科物种,研究了不同浓度的PS-MPs(0、5、50、100和200mgL-1)。结果表明,微塑料暴露抑制细胞分裂,导致与对照组相比细胞密度降低。此外,藻类光合活性,如叶绿素含量所示,Fv/Fm,净光合速率,随着微塑料浓度增加到50mgL-1而下降。值得注意的是,微塑料水平的升高(100和200mgL-1)促使S.tridacnidorum的细胞大小显着增加。透射电镜和荧光显微镜显示,高水平的PS-MPs与藻类细胞之间形成异质聚集,最终对S.Tridacnidorum造成损害。此外,研究了PS-MPs暴露对S.tridacnidorum相关细菌群落的影响.结果表明,与用0和5mgL-1处理的那些相比,暴露于50、100和200mgL-1微塑料的组的细菌群落的α多样性降低。此外,马氏杆菌的相对丰度,Marivita,和Filomicrobium显著增加,而Algiphilus和norankNannocystaceae在微塑料暴露后下降。这些发现表明,MPs可以抑制S.tridacnidorum的生长并改变相关的细菌群落。构成了潜在的严重威胁珊瑚共生涉及S.tridacnidorum。
Microplastics, ubiquitous anthropogenic marine pollutants, represent potential threats to coral-Symbiodiniaceae relationships in global reef ecosystems. However, the mechanism underlying the impacts of polystyrene microplastics (PS-MPs) on Symbiodiniaceae remains poorly understood. In this study, the cytological, physiological, and microbial responses of Symbiodinium tridacnidorum, a representative Symbiodiniaceae species, to varying concentrations of PS-MPs (0, 5, 50, 100, and 200 mg L-1) were investigated. The results revealed that microplastic exposure inhibited cell division, resulting in reduced cell density compared to control group. Furthermore, algal photosynthetic activity, as indicated by chlorophyll content, Fv/Fm, and net photosynthetic rate, declined with increasing microplastic concentration up to 50 mg L-1. Notably, elevated levels of microplastics (100 and 200 mg L-1) prompted a significant increase in cell size in S. tridacnidorum. Transmission electron microscopy and fluorescence microscopy indicated that hetero-aggregation was formed between high levels of PS-MPs and algal cells, ultimately causing damage to S. tridacnidorum. Moreover, the impact of PS-MPs exposure on the bacterial community associated with S. tridacnidorum was investigated. The results showed a reduction in alpha diversity of the bacterial community in groups exposed to 50, 100, and 200 mg L-1 of microplastics compared to those treated with 0 and 5 mg L-1. Additionally, the relative abundance of Marinobacter, Marivita, and Filomicrobium significantly increased, while Algiphilus and norank Nannocystaceae declined after microplastic exposure. These findings suggest that MPs can inhibit the growth of S. tridacnidorum and alter the associated bacterial community, posing a potential serious threat to coral symbiosis involving S. tridacnidorum.