外源一氧化氮供体SNP对黑麦草种子萌发和幼苗生长的影响

Effects of exogenous nitric oxide donor SNP on seed germination and seedling growth of Lolioum multiflorum

采用水培试验，研究了不同浓度NO供体硝普钠（SNP）对黑麦草种子萌发和幼苗生长的影响。结果表明：50和100umol·L^-1 SNP促进了黑麦草种子的发芽率、幼苗干物质积累速率、萌发种子α-淀粉酶活性、幼苗叶片可溶性蛋白质及叶绿素含量的提高。根和叶片中超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、过氧化物酶（POD）和抗坏血酸过氧化物酶（APX）活性及还原型谷胱甘肽（GSH）、抗坏血酸（ASC）含量增加，超氧阴离子（02）积累速率和过氧化氢（H2O2）含量下降，丙二醛（MDA）积累降低。高浓度SNP（500～2000umol·L^-1）抑制种子的萌发和幼苗生长，幼苗叶绿素、可溶性蛋白质及GSH、ASC含量下降，MDA含量和H2O2、O2^-产生速率提高，SOD、POD和APX活性降低，但叶片CAT活性升高。推测NO可能通过提高种子淀粉酶活性和幼苗活性氧清除能力，促进黑麦草种子的萌发和幼苗生长。

By the method of solution culture, this paper studied the effects of different concentrations exogenous nitric oxide （NO） donor （sodium nitroprusside, SNP） on the seed germination and seedling growth of ryegrass （Lolioum multiflorum）. The results showed that 50 and 100 umol SNP · L^-1 increased the seed germination rate, seedling＇ s dry matter accumulation, germinated seed a-amylase activity, and leaf soluble protein and chlorophyll contents. The reduced glutathione （GSH） and ascorbic acid （ASC） contents and the superoxide dismutase （SOD）, catalase （CAT）, peroxidase （POD） and ascorbate peroxidase （APX） activities in seedling＇s roots and leaves also increased, but the generation of O2^- and the accumulation of malondialdehyde （MDA） and H2O2 decreased. High concentration SNP （500 -2000 umol SNP · L^-1） inhibited the seed germination and seedling growth of L. multiflorum. The contents of soluble protein, chlorophyll, GSH and ASC as well as the activities of SOD, POD and APX decreased, but the MDA content, production rates of H2O2 and O2^-, and CAT activity increased. It was suggested that NO could promote the seed germination and seedling growth of L. multiflorum through increasing its seed amylase activity and seedling＇ s scavenging ability of reactive oxygen species.