硝普钠浸种对铜胁迫下棉花种子萌发和幼苗抗氧化系统及铜离子吸收分配的影响OA北大核心

This study aimed to characterize the effects of sodium nitroprussiate(SNP)mediated seed priming on seed germination and early seedling growth of cotton under copper(Cu)stress.Four treatments were established using the upland cotton line A1211 as the experimental material,including water soaking+germination without Cu stress(CK),100 μmol·L-1 SNP soaking+germination without Cu stress(SNP),water soaking+germination under 100 μmol·L-1 Cu2+stress(Cu),and 100 μmol·L-1 SNP soaking+germination under 100 μmol·L-1 Cu2+stress(Cu+SNP).The seed soaking period was set as 24 h.Cotton seed germination,emergence,antioxidant defense system,osmotic adjustment,and copper ion absorption and distribution were investigated in response to SNP presoaking and Cu exposure.The results showed that Cu stress inhibited cotton seedling growth,increasing reactive oxygen species(ROS),malondialdehyde(MDA),proline,and soluble sugar contents and promoting peroxidase(POD),superoxide dismutase(SOD),and ascorbate peroxidase(APX)activities.Compared to Cu stress alone,SNP presoaking combined with Cu stress promoted the growth of seedlings and roots,which was evidenced by significantly increased shoot length and biomass,root biomass and volume,root tips,and total plant biomass.Proline content and antioxidant enzyme activity were increased,while ROS and MDA contents were reduced by SNP soaking together with Cu stress relative to Cu stress alone.The accumulation of Cu ions in seedlings and their transport from roots to shoots under Cu exposure were compromised by SNP application.The concentrations of Cu ions in the stem and the entire plant were significantly decreased by 12.6%and 39.4%,respectively,and the copper transfer factor was remarkably lowered by 40.0%.The present study indicates that priming cotton seeds with SNP contributes to improved growth vigor of cotton seedlings,and can be applied as a pre-sowing treatment for cotton seeds in copper-contaminated farmland.