Centre for Environmental Management, Central Queensland University, Bruce Highway, Rockhampton, QLD 4700, Australia.
Mar Drugs. 2013 Jun 27;11(7):2239-58. doi: 10.3390/md11072239.
To date, most research on freshwater cyanotoxin(s) has focused on understanding the dynamics of toxin production and decomposition, as well as evaluating the environmental conditions that trigger toxin production, all with the objective of informing management strategies and options for risk reduction. Comparatively few research studies have considered how this information can be used to understand the broader ecological role of cyanotoxin(s), and the possible applications of this knowledge to the management of toxic blooms. This paper explores the ecological, toxicological, and genetic evidence for cyanotoxin production in natural environments. The possible evolutionary advantages of toxin production are grouped into two main themes: That of "competitive advantage" or "physiological aide". The first grouping illustrates how compounds produced by cyanobacteria may have originated from the need for a cellular defence mechanism, in response to grazing pressure and/or resource competition. The second grouping considers the contribution that secondary metabolites make to improved cellular physiology, through benefits to homeostasis, photosynthetic efficiencies, and accelerated growth rates. The discussion also includes other factors in the debate about possible evolutionary roles for toxins, such as different modes of exposures and effects on non-target (i.e., non-competitive) species. The paper demonstrates that complex and multiple factors are at play in driving evolutionary processes in aquatic environments. This information may provide a fresh perspective on managing toxic blooms, including the need to use a "systems approach" to understand how physico-chemical conditions, as well biological stressors, interact to trigger toxin production.
迄今为止，大多数有关淡水蓝藻毒素的研究都集中在了解毒素产生和分解的动态，以及评估引发毒素产生的环境条件上，所有这些都是为了为管理策略提供信息，并选择降低风险的方案。相对较少的研究考虑了如何利用这些信息来了解蓝藻毒素的更广泛的生态作用，以及这些知识在有毒水华管理中的可能应用。本文探讨了蓝藻毒素在自然环境中产生的生态、毒理学和遗传学证据。毒素产生的可能进化优势分为两个主要主题：“竞争优势”或“生理辅助”。第一组说明了蓝细菌产生的化合物可能源于对细胞防御机制的需求，以应对放牧压力和/或资源竞争。第二组考虑了次生代谢物对改善细胞生理的贡献，通过对体内平衡、光合作用效率和生长速率的加速产生效益。讨论还包括了关于毒素可能的进化作用的其他因素，例如不同的暴露模式和对非目标（即非竞争）物种的影响。本文表明，在驱动水生环境中的进化过程中，复杂的、多种因素在起作用。这些信息可能为管理有毒水华提供新的视角，包括需要采用“系统方法”来了解物理化学条件以及生物胁迫因素如何相互作用引发毒素产生。
