番茄多梳蛋白家族基因LeEMF2的功能分析  

Functional Analysis of a Polycomb Protein Gene LeEMF2 from Tomato

作　　者：胡节立 杨郁文[2] 凌溪铁 王金彦[2] 吴婧 张保龙[2] 王荣富[1] 

机构地区：[1]安徽农业大学生命科学学院,合肥230000 [2]江苏省农业科学院农业生物技术研究所江苏省农业生物学重点实验室,南京210014

出　　处：《分子植物育种》2016年第1期31-37,共7页Molecular Plant Breeding

基　　金：江苏省自主创新项目(CX(12)2015)资助

摘　　要：多梳蛋白(Polycomb protein)在植物表观遗传调控中起重要作用。已公开的番茄转录组表明一个多梳蛋白基因Le EMF2在抗病番茄CLN2777A中受番茄黄化曲叶病毒(TYLCV)诱导表达。为明确Le EMF2抗TYLCV的作用,我们以CLN2777A为材料,通过RT-PCR克隆该基因全长序列,荧光定量PCR研究Le EMF2的表达模式,并利用病毒诱导的基因沉默(VIGS)技术研究Le EMF2沉默后对番茄抗TYLCV的影响。Le EMF2的开放阅读框为1 917 bp,编码长为638个氨基酸的蛋白。结构域分析表明其含有一个C2H2锌指结构域以及一个VEFS盒,与拟南芥EMF2氨基酸相似度为58.3%。荧光定量PCR发现Le EMF2基因在花、根以及茎顶端生长点的表达量较高,在茎和老叶中表达量次之,在嫩叶中的表达量最低。接种TYLCV 5 d后,Le EMF2基因在CLN2777A中上调表达1倍左右,而在感病番茄TMXA48-4-0的表达则无明显变化。通过农杆菌浸润法将VIGS沉默载体注射CLN2777A子叶15 d后,Le EMF2在沉默番茄植株中的表达量仅为野生型CLN2777A的13%~48%,且沉默株的植株新叶卷曲、皱缩,说明Le EMF2基因对番茄的生长发育、形态建成具有重要作用。Le EMF2沉默植株接种TYLCV 15 d后,荧光定量PCR检测发现沉默植株的病毒量为野生型植株的1.7倍,说明Le EMF2对TYLCV的抗性作用有一定的影响。Polycomb protein g enes play an important role in the epigenetic regulation. According to the open access of the transcriptome of tomato, a polycomb protein gene Le EMF2 was identified up-regulated in response to TYLCV infection in a TYLCV-resistant tomato breeding line CLN2777 A. To verify the TYLCV resistant function of Le EMF2, its full transcript was isolated from CLN2777 A by RT-PCR and the expression pattern was characterized by Real Time RT-PCR. Then the TYLCV resistance was analyzed when the Le EMF2 was transient silenced by the virus induced gene silencing. The length of open reading frame of Le EMF2 was 1 917 bp and encoding a protein with 638 amino acids. Le EMF2 contained the C2H2 zinc finger domain and a VEFS box, which presented 58.3% similarity with the EMF2 of Arabidopsis. Le EMF2 expressed higher in flower, root and shoot apical meristem than the other organs, and the lowest expression was found in leaves. The transcription of Le EMF2 was up-regulated about 1 fold at 5 days after inoculation by TYLCV challenge in CLN2777 A but unchanged in susceptible breeding line TMXA48-4-0. The plants of CLN2777 A with Le EMF2 silenced by TRV silencing system have curled and shrinking leaves, indicating Le EMF2 is vital to the development and morphogenesis of tomato. Then the agroinfiltrated plants were inoculated with TYLCV infectious clone and the virus accumulation was about 1.7 fold than the control at 15 days after inoculation, which indicated Le EMF2 has a certain influence on the TYLCV resistance.

关 键 词：LeEMF2 番茄黄化曲叶病毒 病毒诱导基因沉默 功能分析 

分 类 号：Q943.2[生物学—植物学]