外源NO对盐胁迫下沙打旺种子萌发和幼苗生长的影响  

Effect of nitric oxide on seed germination and seedling growth of Astragalus adsurgens under NaCl stress

作　　者：陈花[1] 王建武[1] 王建军[2] 王富刚[1] 

机构地区：[1]榆林学院生命科学学院,陕西榆林719000 [2]榆林学院能源工程学院,陕西榆林719000

出　　处：《草业科学》2017年第7期1459-1468,共10页Pratacultural Science

基　　金：陕西省教育厅科学研究计划项目(14JK1857);榆林学院校内科研项目(13YK41)

摘　　要：本研究以沙打旺(Astragalus adsurgens)种子为材料,硝普钠(sodium nitroprusside,SNP)为外源NO供体,测定不同浓度(30、60、90、120、150、200、300μmol·L^(-1))SNP处理盐胁迫(0.3%)下沙打旺的种子萌发和幼苗生长,以此探讨NaCl胁迫下外源NO在沙打旺种子萌发和幼苗生长过程中的生理调节功能。结果表明,沙打旺种子和幼苗经SNP处理后,除300μmol·L^(-1) SNP处理对盐胁迫下沙打旺种子萌发和幼苗生长起到一定的抑制作用外,其余SNP处理组均能不同程度地减缓盐胁迫造成的损伤;60μmol·L^(-1)SNP能显著降低盐胁迫对沙打旺种子造成的伤害(P<0.05),该处理下沙打旺种子的发芽势、发芽率、发芽指数、活力指数、胚根长较单盐对照分别提高了54.5%、22.6%、58.2%、112.0%、43.7%,并且接近或略高于空白对照;120μmol·L^(-1)SNP明显减轻了盐对沙打旺幼苗的胁迫(P<0.05),沙打旺幼苗叶片叶绿素含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性分别较单盐对照提高了208.91%、117.565%、40.24%和89.95%,丙二醛含量降低了32.55%。综上所述,适宜浓度的外源NO能够提高盐胁迫下沙打旺种子的萌发,促进幼苗叶绿素的合成,降低丙二醛含量,减少膜脂过氧化产物,保护叶绿体膜的完整性,提高SOD、CAT和POD活性,抑制过氧化物和自由基的积累,加快幼苗生长,从而缓解盐胁迫对沙打旺幼苗的伤害。The aim of this study was to clarify the physiological regulatory function of exogenous nitric oxide （NO） during Astragalus adsurgens seed germination and seedling growth. A. adsurgens was treated with different concentrations of sodium nitroprusside SNP solution as an NO donor under 0.3% NaCl stress and physiological indexes of seed germination and seedling growth were tested. The results showed that under the NaCI stress condition, SNP promoted seed germination and relieved damage at the seedling stage, at concentrations up to 200 μmol·L^-1. However, at the higher concentration of 300 μmol·L^-1 , SNP inhibited seed germination and seedling growth. Damage to A. adsurgens seeds caused by 0.3% NaCI stress was significantly alleviated in the presence of 60 μmol·L^-1 SNP. With SNP treatment under NaCl stress, the seed germination percentage, germination potential, germination index, vigour index, and radicle length were 22.6%, 54.5%,58.20%, 112.00%, and 48.70%, respectively, as compared with controls subjected to NaCl stress without SNP treatment. These values were close to or slightly higher than those of untreated controls （without NaCl stress or SNP）. Treatment with 120 μmol·L^-1SNP significantly reduced the damage to the A. adsurgens seedlings under 0.3% NaCl stress. The chlorophyll content, superoxide dismutase, catalase, and peroxidase activities of A. adsurgens seedling leaves increased by 208.91%, 117.57%, 40.24%, and 89.95%, respectively, while the concentration of malondialdehyde decreased by 32.55%. In conclusion, our experiments demonstrated that an appropriate concentration of exogenous NO could improve seed germination, promote the synthesis of chlorophyll by seedlings, reduce the malondialdehyde content, relieve lipid peroxidation and protect the integrity of the chloroplast membrane, increase superoxide dismutase, catalase, and peroxidase activities, inhibit the accumulation of free radicals and peroxides, and accelerate the growth of seedlings. These physiological processes lowered t

关 键 词：硝普钠 沙打旺 萌发特性 幼苗生长 抗氧化酶 叶绿素含量 丙二醛 

分 类 号：Q945.78[生物学—植物学]