Allelopathy of extracellular chemicals released by Karlodinium veneficum on photosynthesis of Prorocentrum donghaiense

• Published in: Journal of hazardous materials Vol. 476; p. 135079
• Main Authors: Xu, Hongyan, Wang, Yanru, Lin, Kun, Tan, Liju, Wang, Jiangtao
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.09.2024
• Subjects: allelochemicals; Allelopathy; antioxidant enzymes; China; Dinoflagellida - drug effects; Dinoflagellida - metabolism; dominant species; East China Sea; Electron transport; electron transport chain; energy flow; filtrates; fish; Harmful Algal Bloom; human health; Light energy conversion; Marine microalgae; microalgae; Oxidative stress; Oxidative Stress - drug effects; Pheromones; Photosynthesis - drug effects; photosynthetic electron transport; photosystem II; phytoplankton; poisonous algae; Prorocentrum; reproduction; species; Transcriptome analysis; China; East China Sea; Oxidative stress; Transcriptome analysis; Marine microalgae; Electron transport; Light energy conversion
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.135079

Dinoflagellates Prorocentrum donghaiense and Karlodinium veneficum are the dominant species of harmful algal blooms in the East China Sea. The role of their allelopathy on the succession of marine phytoplankton populations is a subject of ongoing debate, particularly concerning the formation of blooms. To explore the allelopathy of K. veneficum on P. donghaiense, an investigation was conducted into photosynthetic performance (including PSII functional activities, photosynthetic electron transport chain, energy flux, photosynthetic different genes and photosynthetic performance) and photosynthetic damage-induced oxidative stress (MDA, SOD, and CAT activity). The growth of P. donghaiense was strongly restrained during the initial four days (1–6 folds, CK/CP), but the cells gradually resumed activity at low filtrate concentrations from the eighth day. On the fourth day of the strongest inhibition, allelochemicals reduced representative photosynthetic performance parameters PI and ΦPSII, disrupted related processes of photosynthesis, and elevated the levels of MDA content in P. donghaiense. Simultaneously, P. donghaiense repairs these impairments by up-regulating the expression of 13 photosynthetic genes, modifying photosynthetic processes, and activating antioxidant enzyme activities from the eighth day onward. Overall, this study provides an in-depth overview of allelopathic photosynthetic damage, the relationship between genes and photosynthesis, and the causes of oxidative damage induced by photosynthesis. As a typical HAB species, Karlodinium veneficum is associated with numerous fish poisoning events, which have negative impacts on aquatic ecosystems and human health. Allelochemicals produced by K. veneficum can provide a competitive advantage by interfering with the survival, reproduction and growth of competing species. This study primarily investigated the effects of K. veneficum allelochemicals on the photosynthesis and photosynthetic genes of Prorocentrum donghaiense. Grasping the mechanism of allelochemicals inhibiting microalgae is helpful to better understand the succession process of algal blooms and provide a new scientific basis for effective prevention and control of harmful algal blooms. [Display omitted] •Unknown allelochemicals from K. veneficum inhibit P. donghaiense.•Allelochemicals induce photosynthesis photosynthetic damage and oxidative stress.•P. donghaiense resists stress by regulating genes and physiological processes.•Low doses stimulate P. donghaiense reproduction but high doses inhibit its growth.