一氧化氮供体硝普钠浸种缓解盐胁迫对小麦种子萌发的抑制作用

以小麦品种‘德抗961＇为材料,用NO供体硝普钠（SNP）浸种研究外源NO对盐胁迫下小麦种子萌发的影响.结果表明：0.06 mmol/L的SNP浸种24 h后对盐胁迫下小麦种子发芽率、发芽指数、活力指数和吸胀速率的下调都有显著缓解作用;SNP浸种对盐胁迫下α-淀粉酶的活性无明显影响,但能显著提高盐胁迫下β-淀粉酶的活性;进一步研究表明,SNP浸种预处理对盐胁迫下的α-淀粉酶同工酶变浅的条带有所恢复（尤其是条带3）,同时使盐胁迫下变浅的β-淀粉酶同工酶的条带有明显的恢复（尤其是d、e、f、g）.并且SNP能显著降低盐胁迫下小麦地上部分和根中的Na^＋含量,提高其K＋含量,从而使K^＋/Na^＋显著提高.以上结果表明：SNP浸种预处理提高盐胁迫下小麦种子的萌发,主要是通过提高β-淀粉酶的活性来实现的.

Priming of Seeds with Nitric Oxide Donor Sodium Nitroprusside (SNP) Alleviates the Inhibition on Wheat Seed Germination by Salt Stress

The effect of SNP, an NO donor, on seed germination of wheat (Triticum aestivum L. cv. 'DK961') under salt stress was studied. The results showed that priming of seeds with 0.06 mmol/L SNP for 24 h markedly alleviated the decrease of the germination percentage, germination index, vigor index and imbibition rate of wheat seeds under salt stress. SNP significantly alleviated the decrease of the beta-amylase activity but almost did not affect the alpha-amylase activity of wheat seeds under salt stress. SNP slightly increased the alpha-amylase isoenzymes (especially isoenzyme 3) and significantly increased the beta-amylase isoenzymes (especially isoenzyme d, e, f and g). SNP pretreatment decreased Na(+) content, but increased the K(+) content, resulting in a mark increase of K(+)/Na(+) ratio of wheat seedlings under salt stress. These results suggested that NO is involved in promoting wheat seed germination under salt stress by increasing the beta-amylase activity.