植物激素对杂交稻籽粒灌浆及蔗糖合酶活性的影响

 以亚种间杂交稻两优培九和品种间杂交稻汕优63为材料，对籽粒灌浆期间的内源激素含量和酶活性进行了测定分析，并结合外源激素对水稻籽粒灌浆过程的调控试验，分析了脱落酸对蔗糖代谢关键酶——蔗糖合酶活性的调节作用。结果表明，灌浆前期强势粒中生长素、玉米素核苷和脱落酸（ABA）含量明显高于弱势粒，并与籽粒最大灌浆速率、平均灌浆速率、籽粒充实率和粒重均呈显著或极显著正相关。强势粒中蔗糖合酶活性明显高于弱势粒，且达到峰值的时间也早于弱势粒。籽粒灌浆速率、籽粒充实率、粒重和淀粉积累速率与蔗糖合酶活性呈显著正相关。花后8 d对稻株喷施低浓度ABA显著提高了籽粒中ABA含量和蔗糖合酶活性，增加了粒重和籽粒充实率。喷施ABA合成抑制剂氟草酮作用则相反。上述结果说明，植物激素尤其是ABA对水稻籽粒灌浆有重要的促进作用，其作用在很大程度上是通过调节籽粒蔗糖合酶活性实现的。

Effects of Plant Hormones in Regulating Sucrose Synthase Activity and Grain Filling of Rice

In order to explore the mechanisms of hormones in the regulation of grain filling,the changes in contents and activities of enzymes which catalyze sucrose metabolism and endogenous hormones in grains during grain filling were analyzed by using inter-subspecies hybrid rice combination Liangyoupeijiu and intervarietal hybrid rice combination Shanyou 63 as materials.Results showed that superior grains had higher contents of endogenous indole-3-acetic acid(IAA),zeatin riboside(ZR) and abscisic acid(ABA) compare...