中文摘要：

纤维素是植物细胞壁的主要成分,纤维素合成酶是纤维素合成过程中重要的酶类。利用拟南芥（草本植物）、水稻（禾本科作物）、毛果杨（木本植物）3种已知全基因组序列的模式植物,对纤维素合成酶基因（CesA）家族的成员进行系统分析,了解CesA基因超基因家族的进化关系。研究结果表明,CesA基因在物种分化之前就已经存在,并且在各个物种内部出现了基因扩张,不同物种扩张程度不同,整个基因家族呈负选择压力。为进一步探讨该家族基因的表达调控模式,以水稻为例对该基因家族的启动子元件进行了分析,发现OsCesA基因可能受到多种胁迫和激素信号的调控;而RT-PCR结果表明ABA可以显著下调该类基因的表达。

英文摘要：

Cellulose is the main component of plant cell walls,and the cellulose synthase encoded by CesA gene is the most important enzyme involved in cellulose biosynthesis.In this study,genome sequence of three model plant species（Arabidopsis thaliana,Oryza sativa,Populus trichocarpa） had been utilized to investigate the phylogenetic relationship of the CesA gene family.The results showed that CesA genes had already existed before species differentiation and that gene expansion occurred after species differentiation.There was a variation in the degree of gene expansion among different species and the entire gene family showed negative selection pressure.To further demonstrate the expression regulation patterns of CesA genes,the promoters of OsCesAs were analyzed and the results suggest that OsCesA genes might be regulated by various stresses and hormones.RT-PCR results indicated that some OsCesAs were down-regulated by abscisic acid.