Abstract: Sucrose synthetase (SuSy) is a crucial enzyme family regulating sucrose metabolism in plants. SH1 is one of the subtypes of SuSy in maize, and its encoding gene (Zmsh1) plays a major role in the catalytic activity of SuSy. Thus, the evaluation of Zmsh1 in biotech breeding has attracted a great deal of  attention in recent years. In this study, we transformed Zmsh1 into tobacco by Agrobacterium-mediated method. The results showed that, enzyme activity of SH1 in the transgenic events exhibited an average of 35% higher than the wild type, and contents of the key metabolites such as sucrose and fructose increased about 23% and 28% respectively in the root and stem of the transgenic events. At the meantime, the transformation of Zmsh1 significantly enhanced the biomass of transgenic tobacco. This preliminary study provided important reference for proving concept of Zmsh1 in maize biotech breeding.

Key words: SuSy, Zmsh1, transgenic tobacco, biomass, prove concept of gene

摘要： 蔗糖合成酶（SuSy）是调控植物体内蔗糖代谢的一类关键酶，而SH1是玉米SuSy的一种亚型。研究表明，玉米SuSy催化活性主要由SH1基因（Zmsh1）决定，该基因在玉米分子育种中的价值评估是人们关注的热点。利用农杆菌介导法将玉米Zmsh1转入模式植物烟草中，发现转基因烟草中SH1酶活力比野生型烟草平均提高了35%，根和茎的糖代谢关键产物蔗糖和果糖的含量平均增加了23%和28%；同时，Zmsh1的转入显著提高了转基因烟草的总生物量。研究结果为进一步在玉米中过表达Zmsh1，评估转基因玉米的产业化应用价值提供了重要的理论参考。

关键词: 蔗糖合成酶, Zmsh1, 转基因烟草, 生物量, 基因应用价值评估