TaMKK9调控小偃6号高温抗条锈性研究OA

[Objective]This study aims to explore the function of TaMKK9 in the process of high-tempera-ture induced stripe rust resistance in Xiaoyan 6,and to elucidate the molecular mechanism underlying the involve-ment of the MAPK(mitogen-activated protein kinase)cascade in wheat's high-temperature induced stripe rust resistance,in order to refine the regulatory network for disease resistance in wheat under high-temperature condi-tions.[Method]Virus-induced gene silencing and virus-induced gene overexpression were used to explore the role of TaMKK9 in wheat's resistance to stripe rust under high-temperature conditions.Real-time fluorescence quantitative PCR was used to detect the expression levels of TaMKK9 and other genes related to disease resis-tance.Downstream interaction targets of TaMKK9 were screened by yeast two-hybridization,and the interac-tion relationship was verified by BiFC,Co-IP,and GST Pull-down.[Result]TaMKK9 was a protein kinase loca-lized to the cell membrane,cytoplasm,and nucleus.Real-time quantitative PCR validation showed that the expression level of TaMKK9 in Xiaoyan 6 was upregulated by 5.17 times,which was induced by stripe rust and high temperature.Compared to the control,Xiaoyan 6 plants with TaMKK9 silenced exhibited more uredinium on leaf surfaces after stripe rust inoculation,accompanied by a 66.9%-94.4%reduction in the expression of the defense-related gene TaPR1.After exposure to high temperature for 24 and 48 hours,H₂O₂ accumulation in leaves decreased by 29.9%and 59.5%,respectively.Overexpression of the TaMKK9 gene in Xiaoyan 6 plants resulted in a 60.5%-72.0%reduction in stripe rust fungus biomass and significantly enhanced disease resis-tance in wheat plants.The interaction verification results between TaMKK9 and TaMPK3 indicated that TaMKK9 interacted with the downstream TaMPK3.[Conclusion]During the resistance process against stripe rust in Xiaoyan 6 under high-temperature conditions,the expression level of TaMKK9 increased due to dual in-duction by stripe rust and temperature.TaMKK9 interacted with the downstream TaMPK3 to transmit immune signals and positively regulates the resistance of wheat plants to stripe rust by affecting H₂O₂ accumulation in plants.