Rice (Oryza sativa L.) is an important food crop, and the normal germination of rice seeds is related to the growth and yield of the plant in the later period. The germination begins with water absorption by dry seeds and ends with cotyl elongation. Water transport within and between cells is highly selectively regulated by aquaporins (AQPs). The seeds of cereal are rich in starch. And the endogenous gibberellin can induce the synthesis of hydrolase such as α-amylase in the embryo and secrete them into the starchy endosperm to degrade starch into small molecules for seed germination. Studies have shown that only α-amylase can complete the degradation of starch in rice seeds. Nitric oxide (NO) is a signaling molecule that forms a variety of active nitrogen substances. It also participated in the signaling process of seed dormancy removal. NO donor plays a role in seed germination by enhancing amylase activity. NO donor can promote seed germination by improving the activity of amylase. Rice hybrid seeds of ‘BoⅡ you 767’ were used as experimental materials to investigate the effects of aquaporins (AQPs) and nitric oxide (NO) on the germination of rice seeds. In this study, NO synthesis inhibitors N-(G)-nitro-L-arginine methyl ester (L-NAME) and sodium tungstate (ST), sodium nitroprusside (SNP), an exogenous donor of NO, and mercury chloride (HgCl2), an activity inhibitor of AQPs, were used to treat rice seeds. The changes of water absorption capacity, amylase activity and starch degradation rate during germination of rice seeds were determined in virtue of apparent analysis and index detection. The results showed that the water absorption capacity, amylase activity and germination rate decreased in the rice seeds treated with 90 mg/L HgCl2, while the starch content remained high, and the growth of radicle and germ was inhibited. However, NO exogenous donor SNP could reverse the effect of HgCl2. And the effect of NO synthesis inhibitors L-NAME (15 mmol/L) and ST (80 µmol/L) on the germination of rice seeds was similar to that of HgCl2. The results indicated that AQPs could induce water uptake, stimulate amylase, accelerate starch degradation and promote seed germination in the early germinating stage of rice seeds through NO. The study would lay a theoretical foundation for improving rice yield.
| 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 |