外源NO供体SNP对PEG模拟干旱胁迫下高羊茅种子萌发及幼苗抗性生理的影响

Inueflnces of Exogenous Nitric Oxide Donor SNP on Seed Germination and Seedling Resistance Physiology in Festuca arundinacea under PEG Simulated Drought Stress

以高羊茅为研究对象,采用不同PEG模拟干旱处理(CK、10%PEG、0.1 mmol/L SNP+10%PEG、1.0 mmol/LSNP+10%PEG等)方法,就外源NO供体SNP对高羊茅种子的萌发、幼苗生长及抗逆性的影响进行了探讨。结果表明,在PEG模拟干旱胁迫下,高羊茅种子的发芽率、发芽势、发芽指数、活力指数和幼苗叶绿素含量较对照呈下降趋势,而幼苗丙二醛(MDA)、脯氨酸、可溶性糖、超氧阴离子(O2.-)和过氧化氢(H2O2)含量呈上升趋势,超氧化物歧化酶(SOD)和过氧化物酶(POD)活性则呈现先升高后降低的趋势。上述结果说明PEG模拟的干旱胁迫,使得高羊茅在种子萌发及幼苗生长过程中遭受逆境胁迫,且生长发育受到显著抑制。经外源NO供体SNP处理后,模拟干旱胁迫下的高羊茅种子发芽率、发芽势、发芽指数、活力指数和幼苗叶片叶绿素、脯氨酸、可溶性糖含量及SOD、POD、CAT活性均显著升高,而幼苗叶片MDA、O2.-和H2O2含量显著下降,说明外源NO供体SNP处理后使PEG模拟干旱胁迫下高羊茅的生长发育得到了促进,减轻了干旱胁迫对高羊茅造成的伤害,提高了植株的整体抗旱性。通过对比几种不同SNP浓度,结果说明0.1 mmol/L SNP对PEG模拟干旱胁迫下高羊茅种子萌发及幼苗的保护效应较为显著。

The seed germination,seedling growth and stress resistance of Festuca arundinacea were discussed in this paper as the different treatment（CK,10% PEG,0.1 mmol/L SNP＋10% PEG,1.0 mmol/L SNP＋10% PEG） were carried out in the experiments.The results showed that Festuca arundinacea seed germination rate,germinating energy,germination index,vigor index and seedling chlorophyll content and catalase（CAT） activities were downward trend,but the content of malondialdehyde（MDA）,proline,soluble sugar,superoxide anion（O-·2） and hydrogen peroxide（H2O2） of seedling leaves increased,the activities of superoxide dismutase（SOD） and peroxidase（POD） increased firstly and then decreased under the simulated drought stress.The results also showed that the growth and development of Festuca arundinacea were inhibited significantly under the simulated drought stress and the seedling suffered from drought stress.As being treated with the exogenous NO donor SNP,the Festuca arundinacea seed germination rate,germinating energy,germination index,vigor index,and the leaves′ content of chlorophyll,proline and soluble sugar,the activities of SOD,POD and CAT increased,the content of MDA,O-·2and H2O2 declined.The results also showed that the growth and development of Festuca arundinacea were promoted,injury mitigated when the seedlings enduring the PEG simulated drought stress being treated with the exogenous NO donor SNP.So it can be concluded that when the seedlings being treated with exogenous NO donor SNP,the protective effect is significant when the seedlings suffered from the 10% PEG solution simulated drought stress.