蔗糖对灌浆期水稻籽粒中蔗糖合酶活性的影响

蔗糖合酶是一种参与植物体内蔗糖代谢的重要酶。实验采用了离体穗培养技术研究蔗糖对蔗糖合酶活性的调节作用。结果表明，蔗糖处理显著提高了水稻籽粒中蔗糖合酶活性，而且蔗糖合酶活性随着蔗糖浓度增加而增加。当用同浓度渗透调节剂甘露醇、山梨醇和氯化钾，及其它单糖如葡萄糖、果糖，以及两者混合物等代替蔗糖处理，都不能产生与蔗糖相同的效应。说明蔗糖对蔗糖合酶活性的影响并不是渗透胁迫引起的。

The Effect of Sucrose on Sucrose Synthase Activity in Rice Grains during Filling Period

Sucrose synthase is an important enzyme for sucrose metabolism of plants. In vitro ear culture was used to determine the regulatory effect of sucrose on sucrose synthase activity. The results indicated that sucrose synthase activity was improved remarkably in rice grains by treatment with sucrose, and promoted with increase of sucrose concentration. If sucrose was replaced by the same concen- tration of osmotica regulators, monosaccharide or its mixtures, such as mannite, sorbierite, potassium chloride, glucose and fructose, the same effect didn＇t appear. It shows that the effect of sucrose on sucrose synthase activity is not due to osmotic stress.