超量表达PMADS20-SRDX的矮牵牛花瓣和雌蕊出现异位表皮毛和气孔  

Over-expressing PMADS20-SRDX Repressor Leads to the Formation of Ectopic Trichome and Stoma on Petals and Pistils in Petunia

作　　者：郭余龙[1] 余勇[1] 杨子[1] 秦小婷[1] 马婧[1] 韩垚[1] 杨霞[1] 李名扬[1] 

机构地区：[1]西南大学园艺园林学院,重庆市花卉工程技术研究中心,南方山地园艺学教育部重点实验室,重庆400715

出　　处：《园艺学报》2014年第3期509-520,共12页Acta Horticulturae Sinica

基　　金：国家自然科学基金项目(31272199)

摘　　要：以矮牵牛(Petunia hybrida)花序cDNA为模板,利用EST数据库信息,克隆了一个MADS-box基因编码区序列,GenBank登录为PMADS20(GU129907)。进化树分析表明,PMADS20属StMADS11亚家族SVP分支,与番茄和辣椒的JOINTLESS基因氨基酸序列相似性最高。定量PCR检测结果表明,PMADS20在矮牵牛营养器官中的表达量高,在花中的表达量低。构建了PMADS20的超量表达载体(35S︰PMADS20)和CRES-T(Chimeric Repressor Gene Silencing Technology)载体(35S︰PMADS20-SRDX)。35S︰PMADS20和35S︰PMADS20-SRDX转基因矮牵牛的花器官表型变化相似,花萼增大,花瓣和雌蕊出现营养器官特征,但35S︰PMADS20-SRDX的变化更为明显。扫描电镜观察显示,35S︰PMADS20-SRDX转基因花瓣下表皮的表皮毛增多,并有气孔分布;子房和花柱表面为表皮毛覆盖,呈现超量表达UNHAVEN的矮牵牛心皮的特征,并且有气孔分布。35S︰PMADS20转基因植株株形无明显变化,35S︰PMADS20-SRDX植株花序的节间较野生型短。Based on EST sequence data analysis, PMADS20 （GU 129907 ） was cloned from Petunia hybrid by PCR using inflorence cDNA as template. Phylogenetic analysis shows that PMADS20 belongs to SVP clade of StMADS11 subfamily and is most closely related to tomato and pepper JOINTLESS. qRT-PCR analysis indicated that PMADS20 mRNA accumulated high level in vegetative organs, and low level in flowers. Vectors of over-expressing PMADS20 and PMADS20-SRDX were constructed. When they were introduced into petunia using Agrobacterium-mediated transformation method, both 35S ： PMADS20 and 35S：PMADS20-SRDX transgenic floral organs exhibited leaf-like characteristics. However, the alterations of 35S：PMADS20-SRDX flowers were more severe than that of the 35S：PMADS20 flowers. The 35S：PMADS20-SRDX petals and pistils showed the unshaven floral phenotype which characterized by ectopic trichome and stoma formation on adaxial side of petals and the surface of ovaries and styles. The results suggest that PMADS20 functions in flower development by transcriptional suppression. Constitutive expression of PMADS20 did not lead to obvious changes in plant stature, while the internodes of 35S ： PMADS20-SRDX transgenic inflorences were shorter than that of the wild type. These results suggest that PMADS20 may function differently between in petunia in florence internode and flower development.

关 键 词：矮牵牛 StMADS11亚家族 PMADS20 花器官发育 

分 类 号：S681.6[农业科学—观赏园艺]