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.