SNP对PEG模拟干旱胁迫下早熟禾种子萌发及幼苗抗性的影响

Influences of exogenous nitric oxide donor SNP on seed germination and seedling resistance of Poa pratensis under PEG simulated drought stress

试验以草地早熟禾为研究对象,采用蒸溜水(CK)、10%PEG、0.1mmol/L SNP+10%PEG和1.0mmol/L SNP+10%PEG 4种胁迫处理就草地早熟禾种子的萌发、幼苗的生长情况及抗逆性进行了探讨.结果表明,在干旱胁迫下,草地早熟禾种子的发芽率、发芽势、发芽指数、活力指数和幼苗叶绿素含量与CAT活性较对照呈下降趋势,而幼苗MDA、H2O2、脯氨酸、可溶性糖含量和SOD、POD活性及超氧阴离子(O-2·)产生速率呈上升趋势,说明草地早熟禾在干旱胁迫下生长发育受到显著抑制.经外源NO供体SNP处理后,和仅有干旱胁迫相比,草地早熟禾种子的发芽率、发芽势、发芽指数、活力指数和幼苗中叶绿素、脯氨酸、可溶性糖含量及SOD、POD、CAT活性呈上升趋势,而MDA、H2O2含量和O-2·产生速率则又呈下降趋势,说明外源NO处理可促进干旱胁迫下草地早熟禾的生长发育,减轻干旱胁迫对草地早熟禾造成的伤害,提高植株的整体抗旱性,而这种抗性与NO浓度呈明显相关性,其中0.1mmol/L SNP处理对干旱胁迫下植株的的保护效应最显著.

Taking Poa pratensis as experimental material, the seed germination, seedling growth and stress resistance of Poa pratensis were studied under different treatments （CK, 10% PEG, 0. 1 mmol/L SNP＋10% PEG and 1.0 mmol/L SNP＋10% PEG）. The results showed that seed germination rate, germinating energy, germination index, vigor index and seedling chlorophyll content and eatalase （CAT） activities decreased under drought stress compared with control,while malondialdehyde （MDA）,hydrogen peroxide （H2O2 ）, proline, soluble sugar contents and superoxide dismutase （SOD）, peroxidase （POD） activity as well as superoxide anion （O2^-） increased. It showed that the growth and development of Poa pratensis were inhibited significantly under drought stress. After treated with exogenous nitric oxide donor SNP,the seed germination rate, germinating energy, germination index, vigor index, seedling chlorophyll content,proline, soluble sugar content, SOD, POD and CAT activity all increased,while the content of MDA, H2O2 and germination rate decreased. It showed that the growth and development of Poa pratensis were promoted, injury of drought stress was mitigated and drought resistance of individuals was improved. The drought resistance was significantly associated with the concentration of NO,and the protective effect was the most significant under the treatment of 0. 1 mmol/L SNP.