The experiment selected five fice cultivars with significant different in grain protein content to analyze gene expression and promoter sequence of glutamine synthetase (GS) and its structural features in grain and leaf at filling stage.The results showed that gene expression was significantly different in OsGS isoform among different cultivars.There was a lot of expression of OsGS1;1 and OsGS1;2 in grain and leaf,OsGS1;3 only in grain and OsGS2 only in leaf to different extent.Gene expression of glutamine synthetase(GS) in grain and leaf exhibited one-peak-curve variation at filling stage,increased to the peak and then decreased quickly.In addition,OsGS expression level was higher in high protein content cultivar than that in low protein content cultivar.Promoter sequence in OsGS genes was more conservative,above 99％ similarity in rice cultivars with significantly different protein contents.Base variation was found in OsGS promoter sequence in progenies from cultivar crossing,but was not involved in core elements.OsGS gene expression level was slightly regulated by its promoter.In the number of regulation elements and its function,the promoter of OsGS gene had strong conservative property and was less likely to have genetic variation in structure and function.The change of OsGS gene mRNA expression was few affected by the regulation of OsGS gene promoter.%研究选用籽粒蛋白质含量差异显著的5个品种(系),比较分析品种间GS同工型基因在灌浆过程中籽粒和叶片表达特性及启动子序列与结构特点.结果表明,不同品种间OsGS同工型基因表达量差异显著;OsGS1;1和OsGSl;2基因在籽粒和叶片中大量表达;OsGS1;3和OsGS2基因分别仅在籽粒和叶片中大量表达;在灌浆过程中籽粒和叶片中OsGS同工型基因mRNA表达量均呈单峰曲线变化,灌浆前期mRNA表达量平稳升高,中期出现峰值,后期快速降低,且高蛋白质含量品种mRNA表达量高于低蛋白质含量品种.籽粒蛋白质含量差异显著品种间OsGS同工型基因启动子序列同源性高达99％以上;品种间有性杂交子代OsGS同工型基因启动子序列可发生碱基变化,但启动子核心元件无变化.在调控元件数量和功能上OsGS同工型基因启动子保守性很强,启动子在结构和功能上不易发生遗传变异,籽粒OsGS同工型基因mRNA表达量变化受OsGS基因启动子调控影响较小.
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