To clarify the physiological mechanism of graphene oxide (GO) acting as a herbicide safener to alleviate the phytotoxicity of nicosulfuron (NIF) on sweet corn, a pair of sweet corn sister lines, HK301 (NIF-tolerant) and HK320 (NIF-sensitive), were used as experimental materials. Using water treatment as a control, the effects of GO-NIF nanocomposite on key enzymes and non-enzymatic substances involved in sugar-starch metabolism in the leaves of sweet corn seedlings were investigated. The results showed that GO-NIF treatment significantly promoted the conversion of sucrose and starch in sweet corn seedlings compared with GO and NIF treatments alone. In HK320, the root to shoot ratio and the contents of sucrose, soluble sugar, and starch under GO-NIF treatment were significantly higher than those under NIF treatment at seven days after treatment, increasing by 30.19%, 71.80%, 79.29%, and 67.87%, respectively. Furthermore, compared with NIF treatment, GO-NIF treatment significantly increased the activities of sucrose phosphate synthase, sucrose synthase, α-amylase, and β-amylase in HK320. A comprehensive evaluation of the effects of different treatments on physiological indicators revealed that HK301 exhibited moderate responses and minimal fluctuations under both NIF and GO-NIF treatments. In contrast, HK320 showed significant physiological regulatory advantages under GO-NIF treatment, particularly manifesting a synergistic enhancement in key enzyme activities of sugar metabolism and the accumulation of saccharides. In conclusion, GO as a safener for NIF can effectively promote the sugar metabolism process as well as the distribution and transport of saccharides in sensitive sweet corn.
| 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 |