The Arabidopsis NUCLEUS- AND PHRAGMOPLAST-LOCALIZED KINASE1-Related Protein Kinases Are Required for Elicitor-Induced Oxidative Burst and Immunity

Abstract

Plant immunity is activated through complex and cross-talking transduction pathways that include a mitogen-activated protein kinase phosphorylation cascade. Here, we have investigated the role in immunity of the Arabidopsis (Arabidopsis thaliana) gene subfamily that encodes the mitogen-activated protein triple kinases indicated as ARABIDOPSIS NUCLEUS-AND PHRAGMOPLAST-LOCALIZED KINASE1-RELATED PROTEIN KINASE1 (ANP1), ANP2, and ANP3. For this study, we used representative danger signals (elicitors) belonging to the classes of the damage-and pathogen-associated molecular patterns, i.e. oligogalacturonides, linear fragments derived from the plant cell wall homogalacturonan, and the peptide elf18 derived from the bacterial elongation factor thermo-unstable. Analyses of single and double as well as conditional triple mutants show that ANPs are required for elicitor-triggered defense responses and protection against the necrotrophic fungus Botrytis cinerea. Notably, ANPs are also required for both the elicitor-induced oxidative burst and the transduction of the hydrogen peroxide signal but not for the inhibition of auxin-induced gene expression, indicating that this response can be uncoupled from the activation of defense responses. Our findings point to ANPs as key transduction elements that coordinate damage-and pathogen-associated molecular patterntriggered immunity and orchestrate reactive oxygen species accumulation and signaling.

A review of redox signaling and the control of MAP kinase pathway in plants

“…In the Wassilewskija (WS) ecotype A. thaliana , elf26-triggered ROS production (30 min) is not reduced in both atmpk6 mutants and atmkp1/atmpk6 (WS) double mutants [53]. Recently, it has been shown that in anp2anp3 (WS) double mutants or β-estradiol-inducible anp1anp2anp3 (WS) conditional triple mutants, elf18-induced production of ROS was compromised but activation of AtMPK3/AtMPK6 was normal [151]. Collectively, these data demonstrate that, in the early stage of PTI (about the first 30 min), PAMP-activated AtMPK3/AtMPK6 may occur independent of the PAMP-triggered ROS production.…”

Modifications of sphingolipid content affect tolerance to hemibiotrophic and necrotrophic pathogens by modulating plant defense responses in Arabidopsis

“…8). Several studies demonstrated that resistance against B. cinerea (and other necrotrophs) is accompanied by the generation of ROS, and mutants impaired in ROS production failed to resist the necrotrophic pathogen (Contreras-Cornejo et al, 2011;Kraepiel et al, 2011;L'Haridon et al, 2011;Rasul et al, 2012;Savatin et al, 2014;Zhang et al, 2014). It has been shown that LCBs but not LCB-Ps alone are able to induce ROS production (Peer et al, 2011).…”

The plant cell wall integrity maintenance mechanism – A case study of a cell wall plasma membrane signaling network

“…Homogalacturonan degradation gives rise to small breakage products (OGs), which form ligands that can bind to WAKs (Brutus et al, 2010). This binding activates signaling processes involving salicylic acid (SA), NO and RBOHD-derived ROS as well as signal translation via ANPs/MPK3/MPK6, which induces classic defense responses (Ferrari et al, 2013;Savatin et al, 2014). A recent publication by Wolf and colleagues has provided evidence that pectin in combination with brassinosteroid (BR)-based signaling processes is an important regulator of cell wall integrity (or homeostasis) during growth and development (Wolf et al, 2012b).…”