中文摘要：

MADS-box基因参与植物多种发育过程，尤其在花发育过程中发挥着重要的调控作用。该研究以玉米不育系C48-2及保持系N48-2为材料，采用RT-PCR克隆mads3基因。序列分析发现，在不育系C48-2中该基因编码区发生单碱基突变，导致其推定的蛋白质中5个氨基酸序列发生改变。荧光定量PCR显示，相对于保持系，花粉母细胞时期和四分体时期mads 3基因在C48-2下调表达，而单核期和双核期上调表达。这些结果为进一步了解玉米C型细胞质雄性不育的发生机制提供参考。

英文摘要：

MADS-box genes involve in various developmental processes in plant,and play an important role in the reg-ulation of floral development.In this paper,mads3,a member of MADS box gene family was cloned by RT-PCR in maize.Sequence analysis showed that 8 sits single-base substitution mutations in CDS region were found in CMS-C line in comparison to maintainer line,which may result in 5 individual amino acides change.Furthermore,real-time qPCR analysis showed that mads3 was significantly down-regulated in CMS-C line at tetrad stage,and was signifi-cantly up-regulated at uninucleate stage.These results laid the foundation for further studying the relationship be-tween MADS-box genes and CMS-C in maize.