Time- and dose-dependent allelopathic effects and mechanisms of kaempferol on toxigenic Microcystis growth

作者：Jieming Li, Jieming Li, Linrong Cao, Zhonghui Guo, Guangqi An, Biying Li, Ji Li, Ji Li · 发表于：Ecotoxicology and Environmental Safety · 年份：2021 · DOI：10.1016/j.ecoenv.2021.112508 · 被引用次数：30 · 研究领域：Aquatic Ecosystems and Phytoplankton Dynamics、Biocrusts and Microbial Ecology、Marine Toxins and Detection Methods

) were explored along 14 day-test. Results showed that growth inhibition ratio (GIR) almost elevated with increasing kaempferol dose, and at each dose GIR elevated firstly and fluctuated around 17.8%- > 40%, 53.6%-65.6% and 84.8%-89.3% at 1.75, 3.5 and 7 mg/L kaempferol during mid-late stage, respectively. With rising kaempferol dose, photosynthetic pigments contents (chlorophyll-a, phycobiliproteins), antioxidant response (superoxide dismutase and catalase (CAT) activities, glutathione (GSH) contents) and microcystins (MCs) production were almost increasingly stimulated as cellular protective responses during early-mid stage. However, these parameters (excluding CAT and GSH) were almost increasingly inhibited at late stage by prolonged stress and Microcystis cell was still more severely damaged as dose elevated along test, which could be reasons for increasing GIR with rising kamepferol dose. Persistent stimulation of CAT and GSH at each dose could alleviate cell damage until late stage, thus GIR no longer increased at late stage at each kaempferol dose. Moreover, fewer MCs release under kaempferol stress than control suggested kaempferol as eco-safe algaecide for migrating toxigenic Microcystis-dominated blooms (MCBs) and decreasing MCs risks. Compared with our previous data for luteolin inhibiting toxigenic Microcystis, this study supported formerly-proposed 'flavonoids structure - algicidal activity' relationship that the only OH-location difference between kaempferol and...