Yang Wei, Tan Qian, Qian Shenhua, Huang Yuyue, Xu Elvis Genbo, Long Xizi, Li Wei
Department of Ecological Sciences and Engineering, Chongqing University, Chongqing 400045, China; Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China.
Key Laboratory for City Cluster Environmental Safety and Green Development of the Ministry of Education, School of Ecology, Environment and Resources, Guangdong University of Technology, Guangzhou, 510006, China.
Aquat Toxicol. 2023 Dec;265:106735. doi: 10.1016/j.aquatox.2023.106735. Epub 2023 Oct 29.
Natural infochemicals may largely affect the trophic transfer of microplastics (MPs) in ecosystems but such infochemical effect and mechanisms are poorly understood. Here, a daphnids-zebrafish freshwater microcosm was designed to elucidate whether and how an algae-derived infochemical, dimethylsulfoniopropionate (DMSP), affects the ingestion and transfer of MPs. Daphnids fast accumulated DMSP and MPs from water, and DMSP in daphnids was mainly enriched from the DMSP in water but not from MPs. DMSP did not change the MP ingestion by daphnids. A low concentration of DMSP (0.5 nM) increased predation of daphnids by zebrafish, while high concentrations of DMSP (50, 100 and 200 nM) did not increase predation rates. The concentration of DMSP in daphnids and the MP predation by zebrafish showed a unimodal relationship. The predation for MP by zebrafish in the 0.5 and 5 nM DMSP treatments was 1.89 and 1.56 times that of the control, respectively. The concentrations of DMSP in freshwater samples were lower than 50 nM. This suggests DMSP at environmentally relevant concentrations may promote the trophic transfer of MPs in freshwater ecosystems via olfactory traps.
天然信息化学物质可能在很大程度上影响生态系统中微塑料（MPs）的营养转移，但这种信息化学效应及其机制却鲜为人知。在此，设计了一个水蚤-斑马鱼淡水微观世界，以阐明藻类衍生的信息化学物质二甲基巯基丙酸内盐（DMSP）是否以及如何影响微塑料的摄取和转移。水蚤从水中快速积累DMSP和微塑料，水蚤体内的DMSP主要从水中的DMSP富集而来，而非来自微塑料。DMSP并未改变水蚤对微塑料的摄取。低浓度的DMSP（0.5 nM）增加了斑马鱼对水蚤的捕食，而高浓度的DMSP（50、100和200 nM）并未提高捕食率。水蚤体内DMSP的浓度与斑马鱼对微塑料的捕食呈单峰关系。在0.5 nM和5 nM DMSP处理中，斑马鱼对微塑料的捕食分别是对照组的1.89倍和1.56倍。淡水样本中DMSP的浓度低于50 nM。这表明环境相关浓度的DMSP可能通过嗅觉诱捕促进淡水生态系统中微塑料的营养转移。
