Different surface modified polystyrene nanoplastics can affect growth adaptability of Skeletonema costatum to heat stress

Microalgae play an essential role in maintaining the balance of the marine ecosystem, but they are often more vulnerable to global change and environmental pollution. In this study, we assessed the effects of heat stress (HS) and polystyrene nanoplastics (NPs) with different surface modifications (PS, PS-NH2, and PS-COOH) on the growth of microalgae Skeletonema costatum (S. costatum). The results indicate that elevated temperature stimulated growth in S. costatum, but NPs impaired their thermal acclimatization. Transcriptome analysis showed that NPs significantly influence the transcriptome of S. costatum under HS in a surface group-dependent manner. The microalgae support growth under elevated temperature by increasing energy production. However, NPs altered these responses, particularly in the HS + (PS-NH2) group. The study provides new insights into how microalgae respond to dual stressors of elevated temperature and NPs, highlighting the need for further research on long-term stress effects to understand microalgal adaptation mechanisms under climate change scenarios.