硝普钠对镧胁迫下黑麦草幼苗叶片碳氮代谢和抗氧化系统的影响

Effects of SNP on Carbon and Nitrogen Metabolism and Antioxidant System in Ryegrass Seedling Leaves under Lanthanum Stress

为了探讨一氧化氮(NO)对镧胁迫下牧草生理响应的调节作用,采用水培方法,研究了NO供体硝普钠(SNP)对300μmol.L-1LaCl3胁迫下黑麦草幼苗生长、碳氮代谢和抗氧化系统的影响。结果表明:LaCl3胁迫下,喷施50μmol.L-1SNP能显著缓解幼苗生物量的下降,提高叶片超氧化物歧化酶和抗坏血酸过氧化物酶活性,降低超氧阴离子(O2.-)产生速率及H2O2和丙二醛含量;促进可溶性糖和可溶性蛋白质积累,提高二磷酸核酮糖羧化酶、磷酸烯醇式丙酮酸羧化酶、内肽酶和羧肽酶活性。表明NO可通过提高活性氧清除能力,维持碳氮代谢正常运转,从而缓解LaCl3胁迫对黑麦草生长的抑制作用。

To explore the regulating effect of nitric oxide（NO） on physiological response of herbage under La stress,the effects of exogenous NO donor sodium nitroprusside（SNP） on growth and leaf carbon and nitrogen metabolism and antioxidant system in ryegrass（Lolium Perenne L.） seedlings under 300 μmol · L-1 LaCl3 stress were investigated by a hydroponic experiment.The results showed that under the stress,spraying 50 μmol · L-1 SNP alleviated plant biomass decreased significantly,and increased the activities of leaf superoxide dismutase and ascorbate peroxidase,and also decreased the O2 ·-release rate and the contents of H2O2 and MDA.In addition,the SNP significantly increased the contents of soluble sugar and soluble protein as well as the activities of ribulose-1,5-bisphosphate carboxylase,phosphoenolpyruvate carboxylase,endopeptidase and carboxypeptidase in leaves of the seedlings under LaCl3 stress.These results suggested that NO could promote the scavenging of reactive oxygen,keep the metabolism between carbon and nitrogen in balance in seedlings growing under LaCl3 stress,and alleviated the inhibition of LaCl3 stress on the ryegrass growth.