We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
ROS meditated paralytic shellfish toxins production changes of Alexandrium tamarense caused by microplastic particles
Summary
Researchers investigated how polystyrene microplastics affect toxin production in Alexandrium tamarense, a harmful algal bloom-causing dinoflagellate. The study found that microplastic exposure triggered elevated reactive oxygen species levels, which in turn stimulated overproduction of paralytic shellfish toxins through enhanced biosynthesis pathways, providing the first evidence that microplastics can indirectly increase harmful algal toxin levels through oxidative stress mechanisms.
A variety of studies have investigated the toxic effects of microplastics (MPs) on microalgae, but few of them considered their influence on dinoflagellate toxins production, which could cause significant ecological safety concerns in coastal areas. This research investigated the impacts of 5 μg L and 5 mg L polystyrene (PS) MPs on the changes of paralytic shellfish toxins (PSTs) production and their relationship with cellular oxidative stress of Alexandrium tamarense, a common harmful algal blooms causative dinoflagellate. The results showed elevation of reactive oxygen species (ROS) levels, activation of antioxidant system and overproduction of PSTs were positively correlated under PS MPs exposure (especially under 5 mg L PS MPs), and the PSTs changes were eliminated by the ROS inhibitor. Further transcriptomic analysis revealed that ROS could enhance biosynthesis of glutamate, providing raw materials for PSTs precursor arginine, accompanied with enhanced acetyl-CoA and ATP production, finally leading to the overproduction of PSTs. Moreover, the oxidative intracellular environments might block the reduction process from STX to C1&C2, leading to the increase of STX and decrease of C1&C2 proportions. This work brings the first evidence that ROS could mediate PSTs production and compositions of Alexandrium under MPs exposure, with important scientific and ecological significance.