Functional Research Of Transcription Factor TaNF-YC1 In The Interaction Between Wheat And The Stripe Rust

Wheat is one of the most important food crops in the world.More than 2.5 billion people live by wheat as the main food.The safe,stable and high-quality production of wheat is crucial to world food security.Stripe rust is one of the main diseases threatening global wheat production,which cause 50% to 80% yield loss in severe outbreaks.Cultivating disease-resistant varieties is a more environmental friendly and more effective disease control measure,but varietal resistance will be overcomed due to the virulent variation of stripe rust fungus,Puccinia striiformis f.sp tritici(Pst),leading to disease outbreaks again.Therefore,discovering new resistant-relative genes,studying its molecular regulation mechanism,and creating new disease-resistant materials will be constructive for breeding new disease-resistant varieties,and it is of great significance to achieve long-term effective prevention and control of wheat stripe rust disease in China.Transcription factors(TFs)are a class of proteins that specifically bind to cis-acting elements of promoters at specific time and space.They regulates the expression of downstream genes,and take part in the regulation of growth/development and responses to biotic/abiotic stresses.Our group has identified a NF-YC transcription factor gene,TaNF-YC1,which expression was strongly induced at 48 hours post inoculation when Swon11,a wheat cultivar,inoculated with the avirulence Pst race,CYR23.And transient silencing of TaNF-YC1 reduced wheat resistance against Pst.On the basis of previous research,this study combined bioinformatics,genetics,molecular biology,biochemistry,histopathology and other techniques to investigate the function and effect of TaNF-YC1 in wheat response to Pst infection.The main results are as follows:1.TaNF-YC1 positively regulates the resistance of wheat against stripe rust.In order to explore the function of TaNF-YC1 in wheat response to Pst infection,the TaNF-YC1-overexpression wheat and TaNF-YC1-RNAi wheat were created and identified.It was found that after inoculation with the virulence Pst race CYR31,the disease resistance of TaNF-YC1 overexpression plants were significantly improved,the accumulation of reactive oxygen species(ROS)near the infection point increased,and the Pst hypha length and the Pst colony area decreased.After inoculation with the avirulence Pst race CYR23,the disease resistance of TaNF-YC1-RNAi plants were significantly decreased,the accumulation of ROS near the infection point decreased,and the Pst hypha length and the Pst colony area increased.Through these experiments,it was confirmed that TaNF-YC1 is an important resistant factor,which positively regulates the resistance of wheat against Pst.2.TaNF-YC1 is a NF-YC transcription factor with transcriptional activity.TaNF-YC1 was confirmed has three homologous genes in wheat,named TaNF-YC1-6A,TaNF-YC1-6B and TaNF-YC1-6D by Blast and sequence alignment,all three genes were induced by Pst.Protein domain prediction indicates TaNF-YC1 has a CBFD＿NFYB＿HMF domain,which can bind to the CCAAT-box element in the promoter region.Agrobacterium-infected tobacco experiment confirmed that TaNF-YC1 was localized in the cytoplasm and nucleus.Yeast self-activation experiment confirmed that TaNF-YC1 has transcriptional activity,and the activity sites are located at the N-terminal and C-terminal of TaNF-YC1.Through the above experiments,it was confirmed that TaNF-YC1 is a NF-YC transcription factor with transcriptional activity.3.TaNF-YC1 improves wheat disease resistance by activating the expression of resistance-related genes.Ch IP-Seq was impled to analyze the wheat disease resistance network activated by TaNF-YC1 after Pst infection.KEGG enrichment analysis revealed TaNF-YC1 regulates typical plant disease resistance pathways,MAPK signaling pathway and calcium signaling pathway.Transcriptional activation of TaNF-YC1 on Ta RPM1 and Ta ACD6,which highly enriched genes in Ch IP-Seq and relative to plant immunity were verified by q RT-PCR in TaNF-YC1 overexpression plants and the dual-luciferase reporter experiment in wheat protoplasm,indicating TaNF-YC1 can activate the expression of these genes.The results indicated that activating the expression of Ta RPM1,Ta ACD6 and other disease resistance-related genes can activate the wheat disease resistance immune network and improve stripe rust resistance.In conclusion,TaNF-YC1 is a transcription factor induced by Pst,and its overexpression increases the resistance of wheat against Pst,while silencing reduces the resistance.TaNF-YC1 is a NF-YC transcription factor,localized in the cytoplasm and nucleus,and has transcriptional activities.In the process of wheat response to stripe rust infection,TaNF-YC1 regulated the plant disease resistance immune signaling pathway and activated the expression of disease resistance-related genes Ta RPM1 and Ta ACD6.This research preliminarily revealed the function and molecular mechanism of TaNF-YC1 involved in regulating wheat stripe rust resistance,providing a target for wheat stripe rust resistance improvement and a new disease resistance resource for disease resistance breeding.