Spermine (SPM) was utilized to investigate its impact on the accumulation of sucrose synthase (SUS) and the role of SUS as a predictor of sink strength of rice under cyclic water stress. Treatments which consisted of control and SPM were arranged in a randomized complete block design. Biochemical analyses showed significantly higher contents of sucrose, starch and carbohydrate in SPM-treated panicles which pointed to increased loading of sucrose into the grains or conversion of sucrose into starch. Besides, the expression of SUS gene was up-regulated in both inferior and superior spikelets at twenty and three fold, respectively. Correspondingly, SUS enzyme showed an increase in its activity. The high expression of SUS3 during grain filling is linked to the increased capacity for starch synthesis. Grain weight and grain filling rate of SPM-treated spikelets improved due to their large sink capacity and increased number of spikelets per panicle.

利用精胺（SPM）考察其对蔗糖合酶（SUS）积累的影响以及SUS在循环水分胁迫下对下沉强度的预测作用。由对照和SPM组成的治疗以随机完整区组设计进行安排。生化分析表明，经SPM处理的穗中蔗糖，淀粉和碳水化合物的含量明显较高，这表明增加了谷物中蔗糖的负载量或将蔗糖转化为淀粉。此外，下小穗和上小穗中的SUS基因表达分别上调了20倍和3倍。相应地，SUS酶显示出其活性的增加。谷物充实过程中SUS3的高表达与淀粉合成能力的提高有关。