To investigate the developmental toxicity and molecular mechanisms of the water extracts from Ustilaginoidea virens-infected Oryza sativ [mainly containing ustiloxin A (UA)] in Danio rerio embryos.
Danio rerio embryos were exposed to 0.1, 0.5 and 2.5 mg/L of the water extracts from Ustilaginoidea virens-infected Oryza sativ (calculated based on UA concentration) for 120 h. Developmental parameters, including mortality, body length, heart rate, pericardial edema rate and spinal curvature rate, were evaluated. Quantitative real-time polymerase chain reaction was used to determine the messenger ribonucleic acid (mRNA) expression of cardiac development-related genes (Nkx2.5, Tbx5, Tnnt2, Gata4, Nppa, Nppb) and skeletal development-related genes(Col8a1a, Bmp2b, Ngs, Ihh, Shh).
Compared with the control group (Danio rerio culture medium without the water extracts), all exposure groups exhibited significantly higher mortality and pericardial edema rates. In the 0.5 mg/L and 2.5 mg/L groups, spinal curvature incidence significantly increased and body length significantly reduced. Moreover, the heart rate of Danio rerio embryos in the 2.5 mg/L exposure group significantly increased (P<0.05). Gene expression analysis revealed that in the 0.1 mg/L group, the expression of Tbx5, Nppa, Nppb, Bmp2b and Ihh was significantly downregulated. With increasing exposure mass concentrations (0.5 mg/L and 2.5 mg/L), nearly all examined key genes involved in cardiac and skeletal development were markedly suppressed.
The water extract prepared from Ustilaginoidea virens-infected Oryza sativinduces significant developmental toxicity in Danio rerio embryos, particularly impairing cardiac and skeletal development. These effects are likely mediated by the dose-dependent suppression of key developmental genes, suggesting that long-term consumption of Ustilaginoidea virens-infected rice may pose potential health risks to animals.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |