NPR1 paralogs of Arabidopsis and their role in salicylic acid perception

Abstract

Salicylic acid (SA) is responsible for certain plant defence responses and NON EXPRESSER OF PATHOGENESIS RELATED 1 (NPR1) is the master regulator of SA perception. In Arabidopsis thaliana there are five paralogs of NPR1. In this work we tested the role of these paralogs in SA perception by generating combinations of mutants and transgenics. NPR2 was the only paralog able to partially complement an npr1 mutant. The null npr2 reduces SA perception in combination with npr1 or other paralogs. NPR2 and NPR1 interacted in all the conditions tested, and NPR2 also interacted with other SA-related proteins as NPR1 does. The remaining paralogs behaved differently in SA perception, depending on the genetic background, and the expression of some of the genes induced by SA in an npr1 background was affected by the presence of the paralogs. NPR2 fits all the requirements of an SA receptor while the remaining paralogs also work as SA receptors with a strong hierarchy. According to the data presented here, the closer the gene is to NPR1, the more relevant its role in SA perception.

Oxicam-type nonsteroidal anti-inflammatory drugs inhibit NPR1-mediated salicylic acid pathway

“…7a). Instead, our data are consistent with other recent reports by Castello et al 34 and Ding et al 16 that do not show NPR1-NPR3 interactions in the presence of SA. Importantly, TNX treatment did not result in any apparent effects in any combination of NPR1, NPR3 and NPR4 interactions examined ( Supplementary Fig.…”

“…We also tested the effect of TNX treatment on the interactions between NPR1 and NPR3, as well as NPR1 and NPR4, with a yeast two-hybrid assay. Disruption of the NPR1-NPR4 interaction by SA in yeast was confirmed as described previously 12,34 ( Supplementary Fig. 7a, b).…”

Systems Biology of Plant-Microbiome Interactions

“…For understanding microbe-host interactions, a model of the SA signaling pathway will be powerful. The recently described SA receptors, NPR1, NPR3, NPR4 (Canet et al, 2010), together mediate responses to different SA concentrations (Fu et al, 2012;Kuai et al, 2015;Castello et al, 2018). In contrast, the more distant family members, BOP1 and BOP2, appear to have no function in SA signaling (Canet et al, 2012) but have been implicated in developmental programs such as flowering and nodule formation in legumes (Couzigou et al, 2012;Magne et al, 2018).…”

Plant hairy roots enable high throughput identification of antimicrobials against Candidatus Liberibacter spp.

“…First, we evaluated whether gain-of-function genetic studies could be performed using the microbial hairy root system. Nonexpresser of pathogenesis-related gene 1 (NPR1) from Arabidopsis thaliana (AtNPR1 and AT1G64280) 45 is a well-known broad-spectrum immune modulator that is effective against diverse pathogens. NPR1 is a receptor of the defense hormone salicylic acid (SA) and functions as a transcriptional activator of pathogenesis-related (PR) genes in plant defense and systemic acquired resistance (SAR) responses.…”