Arabidopsis AtERF15 positively regulates immunity against Pseudomonas syringae pv. tomato DC3000 and Botrytis cinerea

Abstract

Upon pathogen infection, activation of immune response requires effective transcriptional reprogramming that regulates inducible expression of a large set of defense genes. A number of ethylene-responsive factor transcription factors have been shown to play critical roles in regulating immune responses in plants. In the present study, we explored the functions of Arabidopsis AtERF15 in immune responses against Pseudomonas syringae pv. tomato (Pst) DC3000, a (hemi)biotrophic bacterial pathogen, and Botrytis cinerea, a necrotrophic fungal pathogen. Expression of AtERF15 was induced by infection of Pst DC3000 and B. cinerea and by treatments with salicylic acid (SA) and methyl jasmonate. Biochemical assays demonstrated that AtERF15 is a nucleus-localized transcription activator. The AtERF15-overexpressing (AtERF15-OE) plants displayed enhanced resistance while the AtERF15-RNAi plants exhibited decreased resistance against Pst DC3000 and B. cinerea. Meanwhile, Pst DC3000- or B. cinerea-induced expression of defense genes was upregulated in AtERF15-OE plants but downregulated in AtERF15-RNAi plants, as compared to the expression in wild type plants. In response to infection with B. cinerea, the AtERF15-OE plants accumulated less reactive oxygen species (ROS) while the AtERF15-RNAi plants accumulated more ROS. The flg22- and chitin-induced oxidative burst was abolished and expression levels of the pattern-triggered immunity-responsive genes AtFRK1 and AtWRKY53 were suppressed in AtER15-RNAi plants upon treatment with flg22 or chitin. Furthermore, SA-induced defense response was also partially impaired in the AtERF15-RNAi plants. These data demonstrate that AtERF15 is a positive regulator of multiple layers of the immune responses in Arabidopsis.

The Cuticle Mutanteca2Modifies Plant Defense Responses to Biotrophic and Necrotrophic Pathogens and Herbivory Insects

“…AIG1 is expressed after P. syringae infection (Reuber and Ausubel 1996), while MAPK11 has been described to be induced during the ETI and PAMP-triggered immunity Eschen-Lippold et al 2012. Recently, similar phenotypes to eca2 have been reported for the ET-responsive transcription factor AtERF15, which regulates different layers of plant immunity to P. syringae and B. cinerea, including ROS accumulation and activation of defense-response genes (Zhang et al 2015). Several reports have shown that activation of plant innate immunity by MAMPs from different organisms converges at the induction of a similar set of ERGs (Ferrari et al 2007;Ramonell et al 2002;Zipfel et al 2004Zipfel et al , 2006.…”

Botrytis cinerea B05.10 promotes disease development in Arabidopsis by suppressing WRKY33‐mediated host immunity

“…Potential candidates include the TF ERF96, the Ca 2+ sensor calmodulin‐like‐protein CML37 and glutaredoxin GRXS13. Overexpression of ERF96 enhanced resistance to B. cinerea and enhanced the expression of several JA/ET defence marker genes (Catinot et al ; Zhang et al ). CML37 was shown to positively modulate JA and ABA and to positively affect herbivore resistance (Scholz et al ; Scholz et al ).…”

γ‐Aminobutyric acid and related amino acids in plant immune responses: Emerging mechanisms of action

“…However, there are no links between GHB metabolism and modulation of ROS homeostasis during plant–pathogen interactions (Shelp, Bown, & Zarei, ). Finally, the previously discussed link between GABA and ET can provide a further way to control ROS homeostasis during pathogen attack, given the regulatory role exerted by ET over pathogen‐induced ROS burst (Mersmann, Bourdais, Rietz, & Robatzek, ; Zhang, ) and autophagy (Shibuya, Niki, & Ichimura, ). Autophagy is a highly regulated process aimed to the recycling of cellular components and has been recently proposed to contribute to the bulk clearance of ROS excesses during both biotic and abiotic stress conditions (Signorelli, Tarkowski, Van den Ende, & Bassham, ).…”