腐胺在GA_3促进水稻种子萌发中的作用

INVOLVEMENT OF PUTRESCINE IN GERMINATION OF RICE SEEDS STIMULATED BY GA 3

以水稻盐粳１８７种子为材料，初步研究腐胺（Ｐｕｔ）在ＧＡ３促进种子萌发中的作用。结果表明：种子吸水后４８ｈ内源ＧＡ１＋３、Ｐｕｔ含量和α－淀粉酶活力增强密切相关。外源ＧＡ３（０．１４ｍｍｏｌ／Ｌ）在促进种子大量萌发和α－淀粉酶合成之前（１８ｈ）首先诱导Ｐｕｔ合成高峰。使用无胚半种子的进一步实验证明，外源ＧＡ３可诱导内源Ｐｕｔ含量增加，外源Ｐｕｔ可增强α－淀粉酶活力。

The possible role of putrescine in germination of rice ( Oryza sativa L., Variety: Yanjing 187) seeds stimulated by GA 3 was studied. The results showed that during initial 48 h after outset of imbibition of the seeds at 30 ℃ at dark, increases in endogenous GA 1+3 and putrescine levels were closely correlated with α amylase activity. Exogenous GA 3 (0.14 mmol/L) not only promoted seed germination and earlier increase of α amylase activity, but also resulted in a striking peak of putrescine level at 18 h ahead of the increase of α amylase activity and onset of seed germination. It was confirmed by the experiment with de embryoed half seeds that the raised level of endogenous putrescine was induced by exogenous GA 3 and that α amylase activity was increased by exogenous putrescine. This study suggests that putrescine may directly affect GA 3 regulated seed germination.