The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei, PR China.
College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, Hubei, PR China.
Chemosphere. 2019 Jul;226:851-857. doi: 10.1016/j.chemosphere.2019.04.002. Epub 2019 Apr 2.
Ustiloxin A is a cyclopeptide mycotoxin originally isolated from rice false smut balls (FSBs) that formed in rice spikelets infected by the fungal pathogen Ustilaginoidea virens. Studies have shown that ustiloxin A was toxic to animals, but the toxicological evidence is still lacking. To reveal the negative influence of ustiloxin A on model organism, zebrafish were selected and exposed to ustiloxin A at concentrations of 0, 0.25, 2.5 or 25 μM from 2 h post-fertilization (hpf) to 144 hpf. The hatching rates of embryos in the 25 μM exposure group was 12.85% less than the control group at 96 hpf. Meanwhile, exposure to 0.25, 2.5 or 25 μM ustiloxin A resulted in a distinct dose-dependent increase in mortality rate of embryos at 96 hpf. We also found that exposed to ustiloxin A could cause some other damages on zebrafish larvae, such as growth delay and increased heart rate. In addition, the athletic behavior of zebrafish larvae exposed to ustiloxin A at 25 μM was dramatically different with that of control. Transcriptome sequencing showed that abundances of 339 transcripts (125 up-regulated and 214 down-regulated) were significantly altered in larvae exposed to 25 μM of ustiloxin A. Several of the crucial genes were validated by RT-qPCR. This is the first report on the toxicologic study of ustiloxins against model organism zebrafish. Results suggested that ustiloxins have become a potential danger for food security.
玉米赤霉烯酮 A 是一种环肽真菌毒素，最初从受真菌病原菌玉蜀黍赤霉（Ustilaginoidea virens）感染的水稻小穗形成的假黑穗中分离出来。研究表明，玉米赤霉烯酮 A 对动物有毒性，但毒理学证据仍然缺乏。为了揭示玉米赤霉烯酮 A 对模式生物的负面影响，选择斑马鱼，并在受精后 2 小时（hpf）至 144 hpf 时，用 0、0.25、2.5 或 25 μM 的玉米赤霉烯酮 A 暴露于 0、0.25、2.5 或 25 μM 的玉米赤霉烯酮 A。在 96 hpf 时，暴露于 25 μM 玉米赤霉烯酮 A 的胚胎孵化率比对照组低 12.85%。同时，暴露于 0.25、2.5 或 25 μM 的玉米赤霉烯酮 A 导致 96 hpf 时胚胎死亡率呈明显的剂量依赖性增加。我们还发现，暴露于玉米赤霉烯酮 A 会导致斑马鱼幼虫出现其他一些损伤，如生长延迟和心率增加。此外，暴露于 25 μM 玉米赤霉烯酮 A 的斑马鱼幼虫的运动行为与对照组明显不同。转录组测序显示，暴露于 25 μM 玉米赤霉烯酮 A 的幼虫有 339 个转录本（125 个上调和 214 个下调）的丰度发生了显著改变。通过 RT-qPCR 验证了几个关键基因。这是玉米赤霉烯酮对斑马鱼模式生物进行毒理学研究的首次报道。结果表明，玉米赤霉烯酮已成为食品安全的潜在威胁。
