Morita Akari, Sakauchi Ko, Taira Wataru, Otaki Joji M
The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Okinawa 903-0213, Japan.
Research Planning Office, University of the Ryukyus, Okinawa 903-0213, Japan.
Life (Basel). 2022 Apr 20;12(5):615. doi: 10.3390/life12050615.
Biological effects of the Fukushima nuclear accident have been reported in various organisms, including the pale grass blue butterfly and its host plant . This plant upregulates various secondary metabolites in response to low-dose radiation exposure, which may contribute to the high mortality and abnormality rates of the butterfly in Fukushima. However, this field effect hypothesis has not been experimentally tested. Here, using an artificial diet for larvae, we examined the ingestional toxicity of three radiation-dependent plant metabolites annotated in a previous metabolomic study: lauric acid (a saturated fatty acid), alfuzosin (an adrenergic receptor antagonist), and ikarugamycin (an antibiotic likely from endophytic bacteria). Ingestion of lauric acid or alfuzosin caused a significant decrease in the pupation, eclosion (survival), and normality rates, indicating toxicity of these compounds. Lauric acid made the egg-larval days significantly longer, indicating larval growth retardation. In contrast, ikarugamycin caused a significant increase in the pupation and eclosion rates, probably due to the protection of the diet from fungi and bacteria. These results suggest that at least some of the radiation-dependent plant metabolites, such as lauric acid, contribute to the deleterious effects of radioactive pollution on the butterfly in Fukushima, providing experimental evidence for the field effect hypothesis.
福岛核事故的生物效应已在包括淡青雀斑小灰蝶及其寄主植物在内的各种生物中被报道。这种植物在低剂量辐射暴露下会上调各种次生代谢产物，这可能是导致福岛地区蝴蝶高死亡率和异常率的原因。然而，这一田间效应假说尚未经过实验验证。在此，我们使用幼虫人工饲料，检测了先前代谢组学研究中注释的三种辐射依赖性植物代谢产物的摄入毒性：月桂酸（一种饱和脂肪酸）、阿夫唑嗪（一种肾上腺素能受体拮抗剂）和ikarugamycin（一种可能来自内生细菌的抗生素）。摄入月桂酸或阿夫唑嗪会导致化蛹、羽化（存活）和正常率显著下降，表明这些化合物具有毒性。月桂酸使卵-幼虫期显著延长，表明幼虫生长迟缓。相比之下，ikarugamycin导致化蛹和羽化率显著增加，这可能是由于该饲料对真菌和细菌的防护作用。这些结果表明，至少某些辐射依赖性植物代谢产物，如月桂酸，会导致放射性污染对福岛蝴蝶产生有害影响，为田间效应假说提供了实验证据。
