由长期气候压力引发的海洋浮游植物之间的普遍相互作用是众所周知的群落结构环境干扰者。浮游植物生理的动态响应可能来自种间相互作用,而不是对单个物种的直接气候影响。然而,关于种间神秘相互作用的研究,由生物活性细胞外化合物(BECs)诱导,特别是在共享类似贝类毒素的相关有害藻类之间,是稀缺的。这里,我们调查了BECs如何引发两种臭名昭著的藻类之间的相互作用,Alexandriumminutum和Gymnodiniumcatenatum,具有相似的麻痹性贝类毒素(PST)特征。使用包括电子显微镜和转录组分析在内的技术,在BECs压力下观察到G.catenatum细胞内微环境的明显破坏,包括类囊体膜变形,类蛋白基质收缩和淀粉鞘消失。此外,确定了负责光系统ILhca1/4和Rubisco的基因簇的上调,导致削弱光子捕获和二氧化碳同化。基于原位焦平面阵列FTIR成像,脂质和蛋白质的再分布发生在亚细胞水平。我们的发现揭示了由BEC引发的强烈但被低估的种间相互作用,这是导致低等藻类光合作用和细胞器功能失调的原因,并可能导致浮游植物群落的适应性改变。
Prevalent interactions among marine phytoplankton triggered by long-range climatic stressors are well-known environmental disturbers of community structure. Dynamic response of phytoplankton physiology is likely to come from interspecies interactions rather than direct climatic effect on single species. However, studies on enigmatic interactions among interspecies, which are induced by bioactive extracellular compounds (BECs), especially between related harmful algae sharing similar shellfish toxins, are scarce. Here, we investigated how BECs provoke the interactions between two notorious algae, Alexandrium minutum and Gymnodinium catenatum, which have similar paralytic shellfish toxin (PST) profiles. Using techniques including electron microscopy and transcriptome analysis, marked disruptions in G. catenatum intracellular microenvironment were observed under BECs pressure, encompassing thylakoid membrane deformations, pyrenoid matrix shrinkage and starch sheaths disappearance. In addition, the upregulation of gene clusters responsible for photosystem-I Lhca1/4 and Rubisco were determined, leading to weaken photon captures and CO2 assimilation. The redistribution of lipids and proteins occurred at the subcellular level based on in situ focal plane array FTIR imaging approved the damages. Our findings illuminated an intense but underestimated interspecies interaction triggered by BECs, which is responsible for dysregulating photosynthesis and organelle function in inferior algae and may potentially account for fitness alteration in phytoplankton community.