小麦mRNA剪接因子TaSR与TaHis的互作鉴定及其基因表达分析

Interaction Identification Between mRNA Splicing Factor TaSR and TaHis as well as Expression Analysis of TaSR in Wheat

为研究TaHis基因对小麦赤霉病的抗性机制,首先克隆了TaHis基因全长编码序列,构建了pGBKT7-TaHis诱饵载体,通过酵母双杂交技术对赤霉病诱导的小麦穗部酵母双杂交文库进行筛选,获得互作蛋白后利用酵母双杂交技术和双分子荧光互补技术验证蛋白质之间的互作,并利用RT-qPCR技术对抗感小麦材料中TaHis互作蛋白的赤霉病诱导表达模式进行分析。结果表明,成功构建了pGBKT7-TaHis诱饵载体,经过酵母双杂交文库筛选后,在四缺选择培养基(SD/-Leu/-Trp/-His/-Ade)上获得了18个酵母单克隆。测序后Blast分析发现,共获得5个可能与TaHis互作的蛋白质,其中在6个酵母单克隆中均鉴定到富含丝氨酸/精氨酸的mRNA剪接因子SR45a类蛋白(TaSR)编码序列。以百农4299为材料,克隆了TaSR基因全长编码区,并构建了pGADT7-TaSR载体,酵母双杂交试验表明,pGADT7-TaSR和pGBKT7-TaHis共转化的酵母细胞在四缺培养基(SD/-Leu/-Trp/-His/-Ade/X-α-Gal/AbA)上可以生长且显蓝色,表明TaSR和TaHis在酵母细胞中直接互作;构建了YC-TaHis、YN-TaSR载体,双分子荧光互补试验表明,共转化YC-TaHis和YN-TaSR的烟草细胞中产生强烈荧光信号,进一步验证了TaSR与TaHis的互作。RT-qPCR分析显示,TaSR在抗性材料百农4299中受赤霉病诱导后上调表达,在感病材料百农607中受赤霉病诱导后下调表达,表明TaSR基因表达量与小麦赤霉病抗性呈正相关。综上,小麦TaSR与TaHis存在相互作用,且TaSR基因表达量与小麦赤霉病抗性呈正相关。

To study the resistance mechanism of TaHis gene to Fusarium head blight(FHB)in wheat,the full-length coding sequence of TaHis was cloned,and the bait vector pGBKT7-TaHis was constructed,which was then used as bait for screening a yeast two-hybrid library of wheat ear induced by FHB.After obtaining the interacting proteins,yeast two-hybridization and bimolecular fluorescence complementation were further used to verify the interaction between these proteins,and RT-qPCR was used to analyze the expression pattern of TaHis interacting protein induced by FHB in resistant and susceptible cultivars respectively.The results showed that the bait vector pGBKT7-TaHis was successfully constructed,and 18 yeast monoclones were obtained on the four deficient selection medium(SD/-Leu/-Trp/-His/-Ade)after yeast two-hybrid library screening.Blast analysis showed that a total of 5 proteins were obtained,and the coding sequence of serine/arginine-rich mRNA splicing factor SR45a-like(TaSR)was identified in 6 colonies.We cloned the full-length coding region of TaSR gene from Bainong 4299 and constructed pGADT7-TaSR vector.The experiment of yeast two-hybrid showed that the yeast cells co-transformed with pGADT7-TaSR and pGBKT7-TaHis grew well and appeared blue on SD/-Leu/-Trp/-His/-Ade/X-α-Gal/AbA,indicating that TaSR and TaHis directly interacted in yeast cells.The vectors of YC-TaHis and YN-TaSR were constructed,and the bimolecular fluorescence complementary experiments were performed.The results showed that strong fluorescence signals were generated in tobacco cells co-transferred with YC-TaHis and YN-TaSR,which further verified the interaction between TaSR and TaHis.RT-qPCR analysis of TaSR gene expression showed that TaSR expression was up-regulated in resistant cultivar Bainong 4299,while down-regulated in susceptible cultivar Bainong 607 upon FHB infection,indicating a positive correlation between TaSR expression level and FHB resistance in wheat.To sum up,the interaction between wheat TaSR and TaHis was proved,and TaSR expression level was positively correlated with FHB resistance in wheat.