关键词: 辣椒, 种子萌发, 纳米硅, 盐胁迫, 基因表达

Abstract: In order to explore the effects of exogenous nano‐silicon（SiNPs） on the germination，physiological and biochemical indices and related gene expression of pepper seeds under salt stress，the seeds of two varieties of pepper，Jinghua Wuhu Pepper and Jinghua Pepper No.20，were used as test materials.Four treatments were set up：nano‐silicon treatment（SiNP300/SiNP250），sodium chloride treatment（NaCl），sodium chloride + nano‐silicon treatment（NaCl+SiNP300/NaCl+SiNP250），and distilled water as control（CK）.The germination of pepper seeds under different treatments，the content of active oxygen and the changes in antioxidant enzyme activity were analyzed. The results showed that：Under salt stress，exogenous SiNPs could increase the germination percentage（GP），germination index（GI）and radicle length（RL）of Jinghua Wuhu Pepper and Jinghua Pepper No.20，reduce the degree of lipid membrane peroxidation of pepper radicle under salt stress，and enhance the integrity of pepper radicle lipid membrane.Exogenous SiNPs reduced the activities of catalase（CAT），superoxide dismutase（SOD）and peroxidase（POD）in the radicle of seeds of Jinghua Wuhu Pepper and Jinghua Pepper No.20 under salt stress，reduced the accumulation of malondialdehyde（MDA），hydrogen peroxide（H₂O₂）and superoxide anion（O₂·^-）in the radicle，and reduced the content of proline（Pro）and soluble protein（SP）.The results of qRT‐PCR analysis showed that exogenous SiNPs increased the relative expression levels of ABA decomposition‐related gene CaCYP707A1 and GA synthesis‐related gene CaGA20ox1 in the radicle of pepper under salt stress. Exogenous SiNPs can significantly alleviate the inhibition of pepper seed germination under salt stress by regulating the activity of antioxidant enzymes，reducing the content of ROS，regulating the content of Pro and SP and the expression levels of ABA and GA‐related genes，and improve the germination performance of seeds.

Key words: Pepper, Seed germination, Nano‐silicon, Salt stress, Gene expression