title: The wheat ethylene response factor transcription factor pathogen-induced ERF1 mediates host responses to both the necrotrophic pathogen Rhizoctonia cerealis and freezing stresses.
abstract: Sharp eyespot disease (primarily caused by the pathogen Rhizoctonia cerealis) and freezing stress are important yield limitations for the production of wheat (Triticum aestivum). Here, we report new insights into the function and underlying mechanisms of an ethylene response factor (ERF) in wheat, Pathogen-Induced ERF1 (TaPIE1), in host responses to R. cerealis and freezing stresses. TaPIE1-overexpressing transgenic wheat exhibited significantly enhanced resistance to both R. cerealis and freezing stresses, whereas TaPIE1-underexpressing wheat plants were more susceptible to both stresses relative to control plants. Following both stress treatments, electrolyte leakage and hydrogen peroxide content were significantly reduced, and both proline and soluble sugar contents were elevated in TaPIE1-overexpressing wheat, whereas these physiological traits in TaPIE1-underexpressing wheat exhibited the opposite trend. Microarray and quantitative reverse transcription-polymerase chain reaction analyses of TaPIE1-overexpressing and -underexpressing wheat plants indicated that TaPIE1 activated a subset of defense- and stress-related genes. Assays of DNA binding by electrophoretic mobility shift and transient expression in tobacco (Nicotiana tabacum) showed that the GCC boxes in the promoters of TaPIE1-activated genes were essential for transactivation by TaPIE1. The transactivation activity of TaPIE1 and the expression of TaPIE1-activated defense- and stress-related genes were significantly elevated following R. cerealis, freezing, and exogenous ethylene treatments. TaPIE1-mediated responses to R. cerealis and freezing were positively modulated by ethylene biosynthesis. These data suggest that TaPIE1 positively regulates the defense responses to R. cerealis and freezing stresses by activating defense- and stress-related genes downstream of the ethylene signaling pathway and by modulating related physiological traits in wheat.
authors.affiliation: National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science , Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Xiuliang
authors.initials: X
authors.lastname: Zhu
authors.forename: Lin
authors.initials: L
authors.lastname: Qi
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Shibin
authors.initials: S
authors.lastname: Cai
authors.forename: Huijun
authors.initials: H
authors.lastname: Xu
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Huang
authors.forename: Jiarui
authors.initials: J
authors.lastname: Li
authors.forename: Xuening
authors.initials: X
authors.lastname: Wei
authors.forename: Zengyan
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D001483:Base Sequence; D015536:Down-Regulation / Q000235:genetics; D005030:Ethylenes / Q000096:biosynthesis / Q000378:metabolism*; D005615:Freezing; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D054884:Host-Pathogen Interactions / Q000235:genetics; D008954:Models, Biological; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000378:metabolism*; D030821:Plants, Genetically Modified; D011485:Protein Binding; D019655:Quantitative Trait, Heritable; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012232:Rhizoctonia / Q000502:physiology*; D015398:Signal Transduction / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism; D014908:Triticum / Q000235:genetics / Q000276:immunology / Q000382:microbiology* / Q000502:physiology*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D005030:Ethylenes; D010940:Plant Proteins; D014157:Transcription Factors; C036216:ethylene