NO对低温胁迫下玉米种子萌发及幼苗生理特性的影响

以4℃模拟低温胁迫状况,研究了外源一氧化氮(NO)供体硝普钠(SNP)对低温胁迫下玉米种子萌发、幼苗生长和生理特性的影响。结果表明,低温胁迫下,玉米种子萌发和幼苗生长受到抑制,叶片丙二醛(MDA)含量和相对电导率显著上升,叶片相对含水量、脯氨酸含量和叶绿素含量显著降低。不同浓度的SNP均能显著提高低温胁迫下玉米种子的发芽率、发芽势、发芽指数和活力指数;促进低温胁迫下玉米幼苗的生长;抑制低温胁迫下玉米幼苗叶片MDA含量的上升,降低叶片质膜相对透性,增加相对含水量、脯氨酸含量和叶绿素含量。表明外源NO可缓解低温胁迫对玉米种子萌发及幼苗生长的抑制作用,缓解低温胁迫引起的膜脂过氧化,保护细胞膜免受或减少损伤,提高植物抗低温胁迫的能力。在SNP不同的使用浓度中,以100μmol·L-1SNP对低温胁迫的缓解效果最佳,当SNP浓度过低和过高时均达不到理想的效果。

Effects of Nitric Oxide on Seed Germination and Physiological Reaction of Maize Seedlings Under Low Temperature Stress

The effects of sodium nitropprusside(SNP) as an exogenous nitric oxide donor at the different concentrations on the maize seed germination, growth and physiological reaction of maize seedlings under low temperature stress were studied. The results showed that the low temperature stress inhibited the maize seed germination and growth of seedlings, and increased the malondialdehyde(MDA) content and cell membrane permeability, while decreased the relative water content, the proline content and the chlorophyll content in leaves of maize seedlings. The treatments with SNP at different concentrations could promote the germination rate, germination energy, index of germination and index of vigor of maize seeds, increased growth, relative water content, the proline content and the chlorophyll content, inhibited significantly the MDA content and cell membrane permeability of maize seedlings under low temperature stress. It was shown that exogenous nitric oxide had abating effect on depressed seed germination and growth of maize seedlings, could improve the antioxygen ability of maize seedlings, debasing lipid peroxidation and protect plasma membrane from being destroyed to enhance the resistance of plants under low temperature stress. The best abating effect occurred with the SNP concentration set at 100 μmol·L-1, while higher or lower SNP content had no such satisfactory effect.