Identif ication of a hypersensitive response core peptide of HrpZ and its role in increasing grape downy mildew resistance  

作　　者：Zongbao Fan Xueqiang Guan Zhichang Zhang Yushuai Sun Fei Wang Huiru Chi Yuxin Yao 

机构地区：[1]State Key Laboratory of Crop Biology,Collaborative Innovation Center of Fruit&Vegetable Quality and Efficient Production,College of Horticulture Science and Engineering,Shandong Agricultural University,Tai'an,Shandong 271018,China [2]Shandong Academy of Grape/Shandong Technology Innovation Center of Wine Grape and Wine,Jinan,Shandong 250100,China [3]Zhichang Agricultural Science and Technology Development Co.,Ltd.,Rizhao,Shandong 276511,China

出　　处：《Horticultural Plant Journal》2024年第5期1112-1120,共9页园艺学报（英文版）

基　　金：Major Project of Science and Technology of Shandong Province(Grant No.2022CXGC010605);Fruit Industrial Technology System of Shandong Province(Grant No.SDAIT-06-03);Key Research and Development Program of Shandong Province(Grant No.2022LZGCQY019);Agriculture Improved Variety Project of Shandong Province(Grant No.2020 LZGC008).

摘　　要：Harpins play a key role in inducing disease resistance in crops,and identifying their core functional regions and establishing a system for their efficient expression would be very valuable.In this study,large amounts of soluble fusion proteins of harpin HrpZ and its subpeptides were obtained via the optimized induction conditions(28℃ with 0.5 mmol·L^(-1) IPTG for 6 h)in Escherichia coli BL21(DE3).Hypersensitive response(HR)assays demonstrated that the C-terminal 66 aa of HrpZ(HrpZ_C_2_2)elicited a strong HR in tobacco(Nicotiana benthamiana)and grape(Flame Seedless)leaves.Additionally,treatment with HrpZ,and particularly HrpZ_C_2_2,significantly reduced the disease incidence and severity index of field vine leaves and those inoculated with downy mildew.The determination of the physiological parameters indicated that HrpZ,and especially HrpZ_C_2_2,improved the photosynthesis-and chlorophyll fluorescence-related parameters,enhanced the activity of defense-related enzymes,including SOD,POD,CAT and PAL,and increased the H_(2)O_(2) level.Collectively,we efficiently expressed a core peptide of HrpZ and elucidated its strong ability to elicit a HR and resistance to downy mildew.This research provides insight into understanding the structure and function of HrpZ and will advance the application of HrpZ_C_2_2 to increase the resistance of grapevine to downy mildew.

关 键 词：GRAPEVINE Harpin HrpZ Prokaryotic expression Downy mildew Hypersensitive response 

分 类 号：S436.631.1[农业科学—农业昆虫与害虫防治]