白桦BpSPL2基因启动子的克隆及表达分析

Cloning and Expression Analysis of BpSPL2 Promoter from Betula platyphylla

SPL(SQUAMOSA promoter-binding protein-like)是植物特有的转录因子,研究表明其在参与发育阶段转变、花和果实发育等方面起着重要作用。利用PCR技术从白桦基因组DNA中扩增获得BpSPL2基因上游1 960 bp启动子序列,使用PLACE和Plant CARE在线软件分析序列,发现BpSPL2基因启动子序列中含有与开花、非生物胁迫及激素响应等相关的顺式作用元件,暗示其在植物的生长发育和胁迫应答中起重要作用。进而构建了BpSPL2基因启动子驱动GUS报告基因的植物表达载体,并利用农杆菌介导将其瞬时转化至白桦和拟南芥,通过GUS组织化学染色检测BpSPL2基因启动子的组织表达特性,结果表明BpSPL2基因启动子具有启动子活性,能够驱动GUS基因在白桦和拟南芥中表达;而其表达活性在白桦的叶片、芽及根部中较强,在拟南芥的花药、雌蕊和叶片较强,为进一步研究白桦BpSPL2基因的表达调控及其功能分析提供参考。

The SPL(SQUAMOSA promoter-binding protein-like)is a plant specific transcription factor,and the study showed that it plays an important role in the transformation of developmental stage,flower and fruit development.A 1 960 bp promoter sequence of BpSPL2 gene was cloned from Betula platyphylla genomic DNA using the method of PCR.The cis-regulatory elements were analyzed by PLACE and PlantCARE web tools.Multiple flowering elements,abiotic stress response elements and hormone-responsive elements were predicted in the promoter region.It indicated that it played an important role in plant growth and development and stress response.Further,the BpSPL2 promoter was inserted to pBI121 vector under control of the 35S promoter to generate the pBI121-BpSPL2 promoter::GUS recombinant construct,which was transient expressed in B.platyphylla and Arabidopsis thaliana seedlings by Agrobacterium tumefaciens mediated method,then investigated the expression pattern via histechemical GUS staining.BpSPL2 promoter could drive the expression of GUS gene in B.platyphylla and A.thaliana,and expressed in high level in leaves,buds,and roots of B.platyphylla while in high level in anthers,pistils,and leaves of A.thaliana.This study will provide a reference for further studies on the expression regulation and functional analysis of BpSPL2 gene in B.platyphylla.