拟南芥株型突变体zpr1的性状特征与基因鉴定分析

Characteristics and Genetic Analysis of Plant Type Mutant zpr1 in Arabidopsis

对本研究室经T-DNA插入法获得的拟南芥株型突变株系——隐性突变体zpr1植株进行植物学性状调查和遗传分析,并对该突变基因进行鉴定、表达定位和调控元件分析。结果显示:(1)性状分析表明,与野生型拟南芥Ws-2相比,突变体zpr1的茎生叶分枝数量增加,茎生叶分枝发生于拟南芥顶端花序部位;野生型拟南芥茎生叶为披针形,而突变体zpr1没有出现分枝的茎生叶呈倒卵形,出现分枝的茎生叶呈披针型;突变体zpr1的主花序高度、株高、分枝高度和分枝长度都高于野生型,且分枝数多于野生型。(2)利用质粒挽救和反向PCR法(IPCR)确定了ZPR1基因突变发生位置是该基因起始密码子上游426bp处,证明T-DNA插入破坏了ZPR1基因的启动子区域,导致该基因在拟南芥内不能正常表达。(3)基因转录调控区域的顺式作用元件分析发现在ZPR1基因的转录调控区有多个与植物激素相关的调控元件,还有与光周期调节相关的调控元件。(4)亚细胞定位发现,ZPR1基因在所有细胞中的细胞膜中表达,而在部分细胞的细胞膜、细胞质和细胞核中均有表达。研究表明,ZPR1基因的表达对植物株型发育有重要的调控作用,该基因的表达水平受植物激素和光照的调节,最终导致了植物株型的变化。

Here a novel mutant zpr1 in Arabidopsis was screened and identified.In order to provide reference for crop architecture improvement,the phenotypic characteristics and molecular mechanism of the Arabidopsis mutant line zpr1 were studied.Mutant zpr1 is a recessive T-DNA insertion line and was investigated in phenotypic characteristics and genetic analysis.The gene was cloned and expressed in plant,as well as cis-acting elements were studied.（1）According to the observation of the phenotypic characters,comparing to the wild type Ws-2,the stem branch number of mutant line zpr1 was increased near terminal inflorescence.The stem leaves of mutant line zpr1 were lanceolate leaves different from the obovate leaves of wild-type.The other phenotypic characters such as the height of main inflorescence,plant height,branch height,and branch length in mutant zpr1 were higher than those in wild type,and the branch numbers were also higher.（2）Plasmid rescue and IPCR identified the position of mutant gene was 426 bp upstreamof the start codon of the Arabidopsis gene ZPR1 and showed that the insertion of T-DNA fragment in the promoter region of ZPR1 abolished its expression.（3）Analysis of the cis-acting element of transcriptional regulatory region identified multiple regulatory elements which had relation to plant hormones and photoperiod.（4）The study on protein subcellular localization showed that ZPR1 protein mainly localized in cell membrane,occasionally localized in parts of cell membrane,cytoplasm and the nucleus.It revealed that the expression of ZPR1 has regulatory effects in the plant architecture development and the expression level will regulate the hormone sensitivity and light sensitivity.Eventually,this gene leads to the formation of plant type.