Abstract Cyanotoxins are secondary metabolites of the ubiquitous cyanobacteria and exert their toxicity to plants and humans. Human health can be impacted by cyanotoxin bioaccumulation in crops via irrigation from contaminated water reservoirs. In the present study we conducted an ecologically relevant experiment in terms of toxin dose, cultivation time and the use of agricultural soil and naturally contaminated irrigation water. We investigated the growth response, protection potential, bioaccumulation profile and the related health risk of two widely consumed root vegetables, radish and carrot, when the exposure to microcystins-rich water commences at different developmental stages, from seed to 4 true leaves stage. Additionally, carrot was subjected to a prolonged depuration phase in order to evaluate its recovery potential. The results indicate a developmental stage-dependent profile of all measured parameters. Severe growth reduction was evident for plants receiving degraded water from the seed stage which reached 50% and 70% for radish and carrots, respectively. The impact was less pronounced when degraded water was first received at subsequent developmental stages. The protection response, in terms of phenolic content, was considerably insufficient to mitigate the stress at the tissue level. The earlier in its life cycle a plant confronts the exposure, the greater microcystins content occurs in its tissue, particularly in the edible parts, posing considerably high health risk for humans upon consumption. Estimated daily toxin intake after consuming treated taproots exceeded the World Health Organization safety threshold by 4 and 5 times for adults and children, respectively. The experimental depuration in carrot only partially alleviated the problem of bioaccumulation and growth impairment, thus, pointing to irreversible hazards. The results highlight the importance of monitoring the major cyanotoxins content in irrigation water and emphasize the necessity to re-visit the regulation/guidelines concerning the origin and quality of the irrigation water in the frame of effective agricultural water management.

中文翻译：

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根茎类蔬菜在真实暴露场景下以发育阶段依赖性方式生物积累微囊藻毒素-LR：以胡萝卜和萝卜为例

摘要 蓝藻毒素是普遍存在的蓝藻的次级代谢产物，对植物和人类都有毒性。通过受污染的水库灌溉，作物中的蓝藻毒素生物积累会影响人类健康。在本研究中，我们在毒素剂量、栽培时间以及农业土壤和自然污染灌溉水的使用方面进行了生态相关实验。我们调查了两种广泛食用的根茎类蔬菜萝卜和胡萝卜在不同发育阶段（从种子到 4 片真叶阶段）开始接触富含微囊藻毒素的水时的生长反应、保护潜力、生物积累特征和相关的健康风险。此外，胡萝卜经过长时间的净化阶段，以评估其恢复潜力。结果表明所有测量参数的发育阶段依赖曲线。对于接受来自种子阶段的降解水的植物来说，生长明显减少，萝卜和胡萝卜分别达到 50% 和 70%。在随后的发育阶段首次接受降解水时，影响不那么明显。就酚类含量而言，保护反应不足以减轻组织水平的压力。植物在其生命周期中越早暴露，其组织中的微囊藻毒素含量就越高，尤其是在可食用部分，食用后对人类的健康构成相当高的风险。成人和儿童食用经过处理的主根后，估计每日毒素摄入量超过世界卫生组织安全阈值的 4 倍和 5 倍，分别。胡萝卜中的实验净化仅部分缓解了生物积累和生长障碍的问题，因此，指出了不可逆转的危害。结果突出了监测灌溉水中主要蓝藻毒素含量的重要性，并强调了在有效农业用水管理框架内重新审视有关灌溉水来源和质量的法规/准则的必要性。