Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas (IPN-CICIMAR), Av. Instituto Politécnico Nacional s/n, Col. Playa Palo de Santa Rita, La Paz C.P. 23096, BCS, Mexico.
Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Col. Playa Palo Santa Rita Sur, La Paz C.P. 23096, BCS, Mexico.
Toxins (Basel). 2022 Sep 3;14(9):616. doi: 10.3390/toxins14090616.
Allelopathy between phytoplankton organisms is promoted by substances released into the marine environment that limit the presence of the dominating species. We evaluated the allelopathic effects and response of cell-free media of Chattonella marina var. marina and Gymnodinium impudicum in the toxic dinoflagellate Gymnodinium catenatum. Additionally, single- and four-cell chains of G. catenatum isolated from media with allelochemicals were cultured to evaluate the effects of post exposure on growth and cell viability. Cell diagnosis showed growth limitation and an increase in cell volume, which reduced mobility and led to cell lysis. When G. catenatum was exposed to cell-free media of C. marina and G. impudicum, temporary cysts and an increased concentration of paralytic shellfish toxins were observed. After exposure to allelochemicals, the toxin profile of G. catenatum cells in the allelopathy experiments was composed of gonyautoxins 2/3 (GTX2/3), decarcarbamoyl (dcSTX, dcGTX2/3), and the sulfocarbamoyl toxins (B1 and C1/2). A difference in toxicity (pg STXeq cell−1) was observed between G. catenatum cells in the control and those exposed to the filtrates of C. marina var. marina and G. impudicum. Single cells of G. catenatum had a lower growth rate, whereas chain-forming cells had a higher growth rate. We suggest that a low number of G. catenatum cells can survive the allelopathic effect. We hypothesize that the survival strategy of G. catenatum is migration through the chemical cloud, encystment, and increased toxicity.
浮游植物之间的化感作用是由释放到海洋环境中的物质促进的，这些物质限制了优势物种的存在。我们评估了无细胞的海洋原甲藻和夜光藻培养基对有毒甲藻赤潮异弯藻的化感作用和赤潮异弯藻的反应。此外，还从含有化感物质的培养基中分离出赤潮异弯藻的单细胞和四细胞链进行培养，以评估暴露后对生长和细胞活力的影响。细胞诊断显示生长受限和细胞体积增大，这降低了细胞的流动性并导致细胞裂解。当赤潮异弯藻暴露于海洋原甲藻和夜光藻的无细胞培养基中时，观察到暂时的休眠和麻痹性贝类毒素浓度增加。暴露于化感物质后，化感实验中赤潮异弯藻细胞的毒素谱由 GTX2/3、dcSTX、dcGTX2/3 和磺基碳酰胺毒素（B1 和 C1/2）组成。在对照组和暴露于海洋原甲藻和夜光藻滤液的赤潮异弯藻细胞之间观察到了毒性（pg STXeq 细胞−1）的差异。赤潮异弯藻单细胞的生长速率较低，而链形成细胞的生长速率较高。我们认为赤潮异弯藻细胞的数量较少可以存活下来。我们假设赤潮异弯藻的生存策略是通过化学云迁移、休眠和增加毒性。
