SLC/AGO1基因控制拟南芥细胞分裂与定向伸长  

SLC/AGO1 Coordinates Cell Division and Expansion in Arabidopsis

作　　者：王文婧[1] 刘婷[2] 郭磊[1] 刘春明[1] 

机构地区：[1]中国科学院植物研究所信号转导与代谢组学研究中心.北京100093 [2]鲁东大学生命科学学院,烟台264025

出　　处：《植物学报》2011年第4期370-378,共9页Chinese Bulletin of Botany

基　　金：科技部重大科学研究计划项目(No.2006CB910600)

摘　　要：植物通过控制细胞分裂和伸长决定器官的形状。为了研究器官形状决定的分子机理,通过EMS诱变分离得到一个叶形细长的拟南芥突变体。细胞生物学观察发现,该基因突变不仅影响了生长点中的细胞分裂,也影响了叶片细胞的形状和数目,其表皮细胞凸起数明显减少,呈单轴向伸长,因此将该突变体定名为slender leaves and cells(slc)。有趣的是,不同组织内细胞分裂和伸长受到不同程度的影响,说明SLC基因在协调细胞分裂和伸长过程中起关键作用。图位克隆结果表明,SLC与小RNA介导的基因沉默相关基因AGO1等位,其第574位组氨酸突变为酪氨酸。slc和ago1杂交F1代植物呈现突变体表型,证明AGO1和SLC确实为同一基因。以上结果表明,SLC/AGO1所介导的转录后基因沉默对控制植物器官和细胞形状决定均起重要作用。The shapes of organs in plants are determined by defined cell divisions and cell elongations.To understand how organ shape is genetically controlled,we used ethyl methanesulfonate（EMS） mutagenesis to identify a mutant with slender leaves,slender leaves and cells（slc）.Cytological studies showed that the mutation affected cell division,as well as cell shape and number.The interdigitation in pavement cells in slc was greatly reduced,in parallel with the formation of gigantic cells with 1-D cell elongation.Of note,the mean cell size in slc was no larger than that in the wild type,which suggests that expansion is at the cost of reduced cell size in other cells.The function of SLC may be to coordinate cell division and expansion to allow proper interdigitation among cells.Map-based cloning revealed that SLC is allelic to AGO1,a key component in post-transcriptional gene silencing.The mutation led to a change from a highly conserved histidine to tyrosine.Our results suggest that AGO1-mediated gene silencing is critical for determining the shapes of cells and subsequent organs.

关 键 词：AGO1 细胞分裂 细胞伸长 叶片形状 转录后基因沉默 

分 类 号：Q942[生物学—植物学]