Non-expressor of pathogenesis-related genes 1 (NPR1) is a key regulator of plant innate immunity and systemic disease resistance. The model for NPR1 function is based on experimental evidence obtained largely from dicots; however, this model does not fit all aspects of Poaceae family, which includes major crops such as wheat, rice and barley. In addition, there is little scientific data on NPR1's role in mutualistic symbioses.
View Article and Find Full Text PDFRNA interference (RNAi) is a biological process in which small RNA (sRNA) molecules sequence-specifically silence gene expression at the transcriptional or post-transcriptional level, either by directing inhibitory chromatin modifications or by decreasing the stability or translation potential of the targeted mRNA. The trigger for gene silencing is double-stranded RNA (dsRNA) generated from an endogenous genomic locus or a foreign source, such as a transgene or virus. The process of gene silencing can be exploited in agriculture to control plant diseases and pests.
View Article and Find Full Text PDFSalicylic acid (SA) is the major metabolite and active ingredient of aspirin; both compounds reduce pain, fever, and inflammation. Despite over a century of research, aspirin/SA's mechanism(s) of action is still only partially understood. Here we report the results of a genome-wide, high-throughput screen to identify potential SA-binding proteins (SABPs) in human HEK293 cells.
View Article and Find Full Text PDFMol Plant Microbe Interact
September 2018
This article is part of the Distinguished Review Article Series in Conceptual and Methodological Breakthroughs in Molecular Plant-Microbe Interactions. Salicylic acid (SA) is a critical plant hormone that regulates numerous aspects of plant growth and development as well as the activation of defenses against biotic and abiotic stress. Here, we present a historical overview of the progress that has been made to date in elucidating the role of SA in signaling plant immune responses.
View Article and Find Full Text PDFMicrorchidia (MORC) proteins comprise a family of proteins that have been identified in prokaryotes and eukaryotes. They are defined by two hallmark domains: a GHKL-type ATPase and an S5 fold. MORC proteins in plants were first discovered via a genetic screen for Arabidopsis mutants compromised for resistance to a viral pathogen.
View Article and Find Full Text PDFSalicylic acid (SA) is an important plant hormone that regulates many aspects of plant growth and development, as well as resistance to (a)biotic stress. Efforts to identify SA effector proteins have revealed that SA binds to and alters the activity of multiple plant proteins-this represents a shift from the paradigm that hormones mediate their functions via one or a few receptors. SA and its derivatives also have multiple targets in animals; some of these proteins, like their plant counterparts, are associated with pathological processes.
View Article and Find Full Text PDFFollowing pathogen infection, activation of systemic acquired resistance (SAR) in uninfected tissues requires transmission of a signal(s) from the infected tissue via the vasculature. Several candidates for this long-distance signal have been identified, including methyl salicylate (MeSA), an SFD1/GLY1-derived glycerol-3-phosphate (G3P)-dependent signal, the lipid-transfer protein DIR1, the dicarboxylic acid azelaic acid (AzA), the abietane diterpenoid dehydroabietinal (DA), jasmonic acid (JA), and the amino acid-derivative pipecolic acid (Pip). Some of these signals work cooperatively to activate SAR and/or regulate MeSA metabolism.
View Article and Find Full Text PDFSalicylic acid (SA) has been shown to regulate various aspects of growth and development; it also serves as a critical signal for activating disease resistance in Arabidopsis thaliana and other plant species. This review surveys the mechanisms involved in the biosynthesis and metabolism of this critical plant hormone. While a complete biosynthetic route has yet to be established, stressed Arabidopsis appear to synthesize SA primarily via an isochorismate-utilizing pathway in the chloroplast.
View Article and Find Full Text PDFFor more than 200 years, the plant hormone salicylic acid (SA) has been studied for its medicinal use in humans. However, its extensive signaling role in plants, particularly in defense against pathogens, has only become evident during the past 20 years. This review surveys how SA in plants regulates both local disease resistance mechanisms, including host cell death and defense gene expression, and systemic acquired resistance (SAR).
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