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.

Bacteria-Triggered Systemic Immunity in Barley Is Associated with WRKY and ETHYLENE RESPONSIVE FACTORs But Not with Salicylic Acid

“…AtERF4 expression is induced by ABA, JA, ET, and abiotic stress, and overexpression of AtERF4 represses ABA responses, whereas it may enhance JA responsiveness (Yang et al, 2005;Memelink, 2009). Other plant AP2-ERFs, including OsERF922 and wheat PATHOGEN-INDUCED ERF1, also appear to regulate abiotic stress tolerance or disease resistance against necrotrophic pathogens mediated by JA, ABA, or ET (Pré et al, 2008;Liu et al, 2012;Moffat et al, 2012;Maruyama et al, 2013;Zhu et al, 2014). Notably, HvERF-like and HvERF44411 were systemically induced by MeJA and/or ABA application (Fig.…”

A Wheat Cinnamyl Alcohol Dehydrogenase TaCAD12 Contributes to Host Resistance to the Sharp Eyespot Disease

“…In barley and wheat, the barley stripe mosaic virus (BSMV)-based VIGS (virus-induced gene silencing) assay has been shown to be an effective reverse genetic tool for rapidly investigating the functions of interest genes (Holzberg et al, 2002; Scofield et al, 2005; Zhou et al, 2007; Zhu et al, 2014). To generate the BSMV:TaCAD12 recombinant construct, a 190-bp sequence of TaCAD12 (from 1011 to 1200 nucleotides in TaCAD12 cDNA sequence) was sub-cloned in an antisense orientation into the Nhe I restriction site of the RNAγ of BSMV ( Supplementary Figure S2 ).…”

Ethylene Signaling in Rice and Arabidopsis: Conserved and Diverged Aspects

“…For instance, TaPIE1 in wheat positively regulates the defense responses to Rhizoctonia cerealis and freezing stresses through activating defense-and stress-related genes downstream of the ethylene signaling pathway (Zhu et al, 2014). ZmDREB1A in maize is potentially useful for plant tolerance to drought, high salinity, or cold stresses (Qin et al, 2004).…”