Study On The Against Downy Mildew Function Of VpiERF113 Transcription Factor In Chinese Wild Grape Vitis Piasezkii

Grape downy mildew is one of the most serious grape diseases caused by plasmopara viticola.Vitis vinifera is the main variety of grape industry with good quality and high commercial value,but it is not resistant to downy mildew.As one of the important origins of grape plants,China has abundant wild grape germplasm resources with high resistance to grape downy mildew,and mining its inherent resistance genes is of great significance for improving the disease resistance of Vitis vinifera.In this experiment,the downy mildew-resistant Chinese wild compound grape’Liuba-8’（Vitis piasezkii accession Liuba-8）and the downy mildew-susceptible European grape’Pinot Noir’（Vitis vinifera cv.Pinot Noir）were inoculated into plasmopara viticola,the leaves at different time points after inoculation were used as materials for transcriptome sequencing,and the disease resistance function of the screened ERF transcription factor ERF113 was studied.The main results were obtained as following:1.Vitis piasezkii accession Liuba-8（Liuba-8）and Vitis Vinifera cv.Pinot Noir（Pinot Noir）were inoculated plasmopara viticola at 0 h（Mock）,12 h,24 h,48 h,96 h and120 h.Though transcriptomic analysis.1376 and 156 DEGs were identified in’Pinot Noir’and’Liuba-8’,respectively.In particular,the up-regulated genes in’Liuba-8’may be associated with resistance to downy mildew.Including signaling transduction（RLK1 and LECRK-S.7）,Ca²⁺signal（CIPK20 and CIPK25）,transcription factor（ERF113/RAP2.6L,TCP13/PTF1,LBD21,UNE10 and APRR2）,oxidative stress（GLP1-15/17,CYP86C1,CYP96A10,PRX12/73,and so on）,transport（SWEET1/10,ABCG5 and ABCC8）,plant hormones（MES1/2,SABP3,GA3ox1,NCED4 and so on）,and protein metabolism（UGT74E2,UGT72B1,SBT1.7 and GIL1）.2.The results of q RT-PCR indicated that Vpi ERF113 was differentially expressed in LB and PN after P.viticola infection.The entire Vpi ERF113 gene sequence is 762 bp,encoding254 amino acids.Compared with wild-type Arabidopsis,the Arabidopsis erf113 reduced Arabidopsis resistance to P.capsici,whereas Vpi ERF113 transgenic Arabidopsis enhanced Arabidopsis resistance to P.capsici.Injecting flg22 into Arabidopsis leaves,it was found that Vpi ERF113 transgenic Arabidopsis accumulated the most hydrogen peroxide,erf113Arabidopsis had the least hydrogen peroxide accumulation,and callose deposition in erf113Arabidopsis relative to wild-type Arabidopsis,indicating that Vpi ERF113 positively regulates the flg22-induced PTI response.In addition,transient heterologous expression of Vpi ERF113 in tobacco leaves was found to enhance the resistance of tobacco to Phytophthora capsici.Vpi ERF113 was localized in the nucleus,and its nuclear localization signal was analyzed.It was found that the resistance of Vpi ERF113 to P.capsici depended on its nuclear localization.The above shows that the heterologous expression of Vpi ERF113 can enhance the resistance of tobacco and Arabidopsis to P.capsici.The experimental results of transient expression in grape leaves showed that overexpression of Vpi ERF113 enhanced the resistance of grape leaves to Downy mildew.These results suggest that Vpi ERF113 has anti-grape downy mildew function.