scholarly journals A fine-tuned interplay of three A. thaliana UDP glucosyltransferases orchestrates salicylic acid homeostasis

2020 ◽  
Author(s):  
Sibylle Bauer ◽  
Elisabeth Georgii ◽  
Birgit Lange ◽  
Rafał P. Maksym ◽  
Robert Janowski ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Stress Responses ◽  
Dominant Role ◽  
Defense Responses ◽  
Loss Of Function ◽  
Combinatorial Set ◽  
Resistance To Infection ◽  
Stress Related Genes ◽  
The Individual

AbstractSalicylic acid (SA) is a central signaling molecule in development and defense, therefore its levels are tightly controlled. One control mechanism is conjugation with sugar moieties by UDP glucosyltransferases (UGTs). In Arabidopsis, UGT76B1, UGT74F1, and UGT74F2 are known to glucosylate SA. We show that these are the main SA UGTs in leaves, since only marginal levels of SA glucosides were found in a triple loss-of-function mutant. Analyzing transcriptomes, metabolite levels, and phenotypes of a full combinatorial set of loss-of-function mutants, we resolved the mutual relationships and the individual roles of these enzymes in SA homeostasis. The strongest gene expression changes were observed for the ugt76b1 ugt74f1 double mutant, which downregulated developmental genes and most pronouncedly upregulated cell death-related genes. Among the single mutants, ugt76b1 specifically exhibited increased production of reactive oxygen species, increased resistance to infection, and early senescence. Likewise, higher-order mutations confirmed the dominant role of UGT76B1 in controlling SA levels and thereby the expression of biotic stress response genes. Both UGT74F1 and UGT74F2 affected UGT76B1 expression. However, while UGT76B1 and UGT74F1 produced SA-2-O-β-glucoside, UGT74F2 did not contribute there substantially. Instead, UGT74F2 acted independently of UGT74F1, decreasing steady-state SA levels by producing salicyloyl glucose ester. Remarkably, this did not restrict defense responses. In contrast, UGT74F1 interacted with UGT76B1 in suppressing defense responses. Nevertheless, a benzothiadiazole-triggered defense scenario induced only UGT76B1, whereas UGT74F1 was linked to controlling abiotic stress responses. All three enzymes form a network that, in concert with other UGTs, regulates expression of developmental and stress-related genes.One sentence summaryThe salicylic acid glucosylating enzymes of Arabidopsis leaves are crucial for salicylic acid homeostasis and combinatorially impact defense responses and developmental processes.

scholarly journals The Emerging Role of Long Non-Coding RNAs in Plant Defense Against Fungal Stress

2020 ◽  
Vol 21 (8) ◽  
pp. 2659
Author(s):  
Hong Zhang ◽  
Huan Guo ◽  
Weiguo Hu ◽  
Wanquan Ji
Keyword(s):  
Stress Responses ◽  
Higher Plants ◽  
Regulatory Elements ◽  
Cellular Functions ◽  
Non Coding Rna ◽  
Non Coding Rnas ◽  
Resistance To Infection ◽  
Regulatory Functions ◽  
Long Non Coding Rna

Growing interest and recent evidence have identified long non-coding RNA (lncRNA) as the potential regulatory elements for eukaryotes. LncRNAs can activate various transcriptional and post-transcriptional events that impact cellular functions though multiple regulatory functions. Recently, a large number of lncRNAs have also been identified in higher plants, and an understanding of their functional role in plant resistance to infection is just emerging. Here, we focus on their identification in crop plant, and discuss their potential regulatory functions and lncRNA-miRNA-mRNA network in plant pathogen stress responses, referring to possible examples in a model plant. The knowledge gained from a deeper understanding of this colossal special group of plant lncRNAs will help in the biotechnological improvement of crops.

scholarly journals Starvation resistance and tissue-specific gene expression of stress-related genes in a naturally inbred ant population

2016 ◽  
Vol 3 (4) ◽  
pp. 160062 ◽  
Author(s):  
Nick Bos ◽  
Unni Pulliainen ◽  
Liselotte Sundström ◽  
Dalial Freitak
Keyword(s):  
Gene Expression ◽  
Stress Responses ◽  
Specific Gene ◽  
Starvation Resistance ◽  
Specific Expression ◽  
Tissue Specific ◽  
Trade Offs ◽  
Stress Related Genes ◽  
The Individual ◽  
Different Tissues

Starvation is one of the most common and severe stressors in nature. Not only does it lead to death if not alleviated, it also forces the starved individual to allocate resources only to the most essential processes. This creates energetic trade-offs which can lead to many secondary challenges for the individual. These energetic trade-offs could be exacerbated in inbred individuals, which have been suggested to have a less efficient metabolism. Here, we studied the effect of inbreeding on starvation resistance in a natural population of Formica exsecta ants, with a focus on survival and tissue-specific expression of stress, metabolism and immunity-related genes. Starvation led to large tissue-specific changes in gene expression, but inbreeding had little effect on most of the genes studied. Our results illustrate the importance of studying stress responses in different tissues instead of entire organisms.

scholarly journals Usp14 is required for spermatogenesis and ubiquitin stress responses in Drosophila melanogaster

2019 ◽  
Author(s):  
Levente Kovács ◽  
Ágota Nagy ◽  
Margit Pál ◽  
Peter Deák
Keyword(s):  
Male Sterility ◽  
Stress Responses ◽  
Expression Patterns ◽  
Loss Of Function ◽  
Wild Type ◽  
Cellular Processes ◽  
Protein Conjugates ◽  
Covalently Linked ◽  
Mutant Phenotypes

ABSTRACTDeubiquitinating (DUB) enzymes free covalently linked ubiquitins from ubiquitin-ubiquitin and ubiquitin-protein conjugates, and thereby maintain the equilibrium between free and conjugated ubiquitins and regulate ubiquitin-mediated cellular processes. The present genetic analyses of mutant phenotypes demonstrate that loss of Usp14 function results in male sterility, with defects in spermatid individualization and reduced testicular free monoubiquitin levels. These phenotypes were rescued by germline specific overexpression of wild type Usp14. Synergistic genetic interactions with Ubi-p63E and cycloheximide sensitivity suggest that ubiquitin shortage is a primary cause of male sterility. In addition, Usp14 is predominantly expressed in testes in Drosophila, and differential expression patterns may be causative of testis-specific loss of function Usp14 phenotypes. Collectively, these results suggest a major role of Usp14 in maintaining normal steady state free monoubiquitin levels during the later stages of Drosophila spermatogenesis.

scholarly journals The Involvement ofNRF2in Lung Cancer

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Alison K. Bauer ◽  
Thomas Hill ◽  
Carla-Maria Alexander
Keyword(s):  
Lung Cancer ◽  
Mouse Models ◽  
Stress Responses ◽  
Loss Of Function ◽  
Mutation Status ◽  
Activating Mutations ◽  
Cellular Stress Responses ◽  
Xenograft Models ◽  
Pulmonary Neoplasia

Nuclear factor, erythroid-derived 2, like 2 (NRF2) is a key regulator of antioxidants and cellular stress responses. The role ofNRF2in pulmonary neoplasia, a diverse disease for which few biomarkers exist, is complicated and appears to depend on several main factors including the existence of activating mutations inNRF2and/or loss of function mutations inKEAP1and the stage of carcinogenesis studied, particularly in the mouse models tested. Therapeutic strategies for lung cancer targetingNRF2have observed mixed results, both anti- and protumorigenic effects; however, these differences seem to reflect the mutation status ofNRF2orKEAP1. In this paper, we will discuss the studies on humanNRF2and the mechanisms proposed, several mouse models using various mice deficient inNRF2, as well as xenograft models, and the chemotherapeutic strategies using theNRF2pathway.

scholarly journals The Role of H2O2-Scavenging Enzymes (Ascorbate Peroxidase and Catalase) in the Tolerance of Lemna minor to Antibiotics: Implications for Phytoremediation

Antioxidants ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 151
Author(s):  
Marcelo Pedrosa Gomes ◽  
Rafael Shinji Akiyama Kitamura ◽  
Raizza Zorman Marques ◽  
Marcello Locatelli Barbato ◽  
Marcel Zámocký
Keyword(s):  
Salicylic Acid ◽  
Oxidative Damage ◽  
Ascorbate Peroxidase ◽  
Heme Proteins ◽  
Aquatic Plant ◽  
Lemna Minor ◽  
Scavenging Enzymes ◽  
The Individual ◽  
Specific Inhibitors

We investigated the individual and combined contributions of two distinct heme proteins namely, ascorbate peroxidase (APX) and catalase (CAT) on the tolerance of Lemna minor plants to antibiotics. For our investigation, we used specific inhibitors of these two H2O2-scavenging enzymes (p-aminophenol, 3-amino,1,2,4-triazole, and salicylic acid). APX activity was central for the tolerance of this aquatic plant to amoxicillin (AMX), whereas CAT activity was important for avoiding oxidative damage when exposed to ciprofloxacin (CIP). Both monitored enzymes had important roles in the tolerance of Lemna minor to erythromycin (ERY). The use of molecular kinetic approaches to detect and increase APX and/or CAT scavenging activities could enhance tolerance, and, therefore, improve the use of L. minor plants to reclaim antibiotics from water bodies.

scholarly journals Salicylic acid-independent role of NPR1 is required for protection from proteotoxic stress in the plant endoplasmic reticulum

2018 ◽  
Vol 115 (22) ◽  
pp. E5203-E5212 ◽  
Author(s):  
Ya-Shiuan Lai ◽  
Luciana Renna ◽  
John Yarema ◽  
Cristina Ruberti ◽  
Sheng Yang He ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Salicylic Acid ◽  
Er Stress ◽  
Stress Responses ◽  
Unfolded Protein ◽  
Redox Activation ◽  
Genetic Level ◽  
The Unfolded Protein Response ◽  
Protein Response

The unfolded protein response (UPR) is an ancient signaling pathway designed to protect cells from the accumulation of unfolded and misfolded proteins in the endoplasmic reticulum (ER). Because misregulation of the UPR is potentially lethal, a stringent surveillance signaling system must be in place to modulate the UPR. The major signaling arms of the plant UPR have been discovered and rely on the transcriptional activity of the transcription factors bZIP60 and bZIP28 and on the kinase and ribonuclease activity of IRE1, which splices mRNA to activate bZIP60. Both bZIP28 and bZIP60 modulate UPR gene expression to overcome ER stress. In this study, we demonstrate at a genetic level that the transcriptional role of bZIP28 and bZIP60 in ER-stress responses is antagonized by nonexpressor of PR1 genes 1 (NPR1), a critical redox-regulated master regulator of salicylic acid (SA)-dependent responses to pathogens, independently of its role in SA defense. We also establish that the function of NPR1 in the UPR is concomitant with ER stress-induced reduction of the cytosol and translocation of NPR1 to the nucleus where it interacts with bZIP28 and bZIP60. Our results support a cellular role for NPR1 as well as a model for plant UPR regulation whereby SA-independent ER stress-induced redox activation of NPR1 suppresses the transcriptional role of bZIP28 and bZIP60 in the UPR.

scholarly journals Structural Basis of Subtilase Cytotoxin SubAB Assembly

2013 ◽  
Vol 288 (38) ◽  
pp. 27505-27516 ◽  
Author(s):  
Jérôme Le Nours ◽  
Adrienne W. Paton ◽  
Emma Byres ◽  
Sally Troy ◽  
Brock P. Herdman ◽  
...  
Keyword(s):  
Dominant Role ◽  
Functional Characterization ◽  
Structural Basis ◽  
Sequence Comparisons ◽  
A Subunit ◽  
The Individual ◽  
A1 Domain ◽  
Cellular Dysfunction

Pathogenic strains of Escherichia coli produce a number of toxins that belong to the AB5 toxin family, which comprise a catalytic A-subunit that induces cellular dysfunction and a B-pentamer that recognizes host glycans. Although the molecular actions of many of the individual subunits of AB5 toxins are well understood, how they self-associate and the effect of this association on cytotoxicity are poorly understood. Here we have solved the structure of the holo-SubAB toxin that, in contrast to other AB5 toxins whose molecular targets are located in the cytosol, cleaves the endoplasmic reticulum chaperone BiP. SubA interacts with SubB in a similar manner to other AB5 toxins via the A2 helix and a conserved disulfide bond that joins the A1 domain with the A2 helix. The structure revealed that the active site of SubA is not occluded by the B-pentamer, and the B-pentamer does not enhance or inhibit the activity of SubA. Structure-based sequence comparisons with other AB5 toxin family members, combined with extensive mutagenesis studies on SubB, show how the hydrophobic patch on top of the B-pentamer plays a dominant role in binding the A-subunit. The structure of SubAB and the accompanying functional characterization of various mutants of SubAB provide a framework for understanding the important role of the B-pentamer in the assembly and the intracellular trafficking of this AB5 toxin.

Role of Salicylic Acid in Survival Strategy of Plants under Changing Environment

2016 ◽  
Vol 2 (1 and 2) ◽  
pp. 79-86
Author(s):  
Pramod K. Singh
Keyword(s):  
Salicylic Acid ◽  
Present Report ◽  
Defense Responses ◽  
Survival Strategies ◽  
Plant Responses ◽  
Changing Environment ◽  
Mediating Role ◽  
Adverse Environmental Conditions ◽  
Oxidative System

In recent years salicylic acid (SA) has been the focus of intensive research due to its function as an endogenous signal mediating role in defense responses after pathogen attack. SA antagonizes gene induction by the stress signaling molecule jasmonic acid (JA). It has also been found that SA plays a role during the plant responses to abiotic stresses. The discovery of its targets and understanding of its mechanism of the action in physiological and molecular processes could help in the sustainable plant productivity. Present report focused on various survival strategies of plants under changing environment and the role of SA in cross-talk signaling, osmoregulation, anti-oxidative system and induction of protein kinases under adverse environmental conditions.

scholarly journals GCN5 modulates salicylic acid homeostasis by regulating H3K14ac levels at the 5′ and 3′ ends of its target genes

2020 ◽  
Vol 48 (11) ◽  
pp. 5953-5966
Author(s):  
Soonkap Kim ◽  
Sophie J M Piquerez ◽  
Juan S Ramirez-Prado ◽  
Emmanouil Mastorakis ◽  
Alaguraj Veluchamy ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Histone Modifications ◽  
Stress Responses ◽  
Target Genes ◽  
Gene Activation ◽  
Loss Of Function ◽  
Biotic And Abiotic Stress ◽  
Promoter Regions ◽  
Genome Wide ◽  
A Genome

Abstract The modification of histones by acetyl groups has a key role in the regulation of chromatin structure and transcription. The Arabidopsis thaliana histone acetyltransferase GCN5 regulates histone modifications as part of the Spt-Ada-Gcn5 Acetyltransferase (SAGA) transcriptional coactivator complex. GCN5 was previously shown to acetylate lysine 14 of histone 3 (H3K14ac) in the promoter regions of its target genes even though GCN5 binding did not systematically correlate with gene activation. Here, we explored the mechanism through which GCN5 controls transcription. First, we fine-mapped its GCN5 binding sites genome-wide and then used several global methodologies (ATAC-seq, ChIP-seq and RNA-seq) to assess the effect of GCN5 loss-of-function on the expression and epigenetic regulation of its target genes. These analyses provided evidence that GCN5 has a dual role in the regulation of H3K14ac levels in their 5′ and 3′ ends of its target genes. While the gcn5 mutation led to a genome-wide decrease of H3K14ac in the 5′ end of the GCN5 down-regulated targets, it also led to an increase of H3K14ac in the 3′ ends of GCN5 up-regulated targets. Furthermore, genome-wide changes in H3K14ac levels in the gcn5 mutant correlated with changes in H3K9ac at both 5′ and 3′ ends, providing evidence for a molecular link between the depositions of these two histone modifications. To understand the biological relevance of these regulations, we showed that GCN5 participates in the responses to biotic stress by repressing salicylic acid (SA) accumulation and SA-mediated immunity, highlighting the role of this protein in the regulation of the crosstalk between diverse developmental and stress-responsive physiological programs. Hence, our results demonstrate that GCN5, through the modulation of H3K14ac levels on its targets, controls the balance between biotic and abiotic stress responses and is a master regulator of plant-environmental interactions.

scholarly journals Spermine Is a Potent Plant Defense Activator Against Gray Mold Disease on Solanum lycopersicum, Phaseolus vulgaris, and Arabidopsis thaliana

2019 ◽  
Vol 109 (8) ◽  
pp. 1367-1377 ◽  
Author(s):  
Hamed S. Seifi ◽  
Adel Zarei ◽  
Tom Hsiang ◽  
Barry J. Shelp
Keyword(s):  
Arabidopsis Thaliana ◽  
Salicylic Acid ◽  
Phaseolus Vulgaris ◽  
Plant Defense ◽  
Solanum Lycopersicum ◽  
Stress Responses ◽  
Systemic Acquired Resistance ◽  
Defense Responses ◽  
Gray Mold ◽  
Systemic Resistance

Polyamines (PAs) are ubiquitous aliphatic amines that play important roles in growth, development, and environmental stress responses in plants. In this study, we report that exogenous application of spermine (Spm) is effective in the induction of resistance to gray mold disease, which is caused by the necrotrophic fungal pathogen Botrytis cinerea, on tomato (Solanum lycopersicum), bean (Phaseolus vulgaris), and Arabidopsis thaliana. High throughput transcriptome analysis revealed a priming role for the Spm molecule in the genus Arabidopsis, resulting in strong upregulation of several important defense-associated genes, particularly those involved in systemic-acquired resistance. Microscopic analysis confirmed that Spm application potentiates endogenous defense responses in tomato leaves through the generation of reactive oxygen species and the hypersensitive response, which effectively contained B. cinerea growth within the inoculated area. Moreover, co-application of Spm and salicylic acid resulted in a synergistic effect against the pathogen, leading to higher levels of resistance than those induced by separate applications of the two compounds. The Spm plus salicylic acid treatment also reduced infection in systemic nontreated leaves of tomato plants. Our findings suggest that Spm, particularly when applied in combination with salicylic acid, functions as a potent plant defense activator that leads to effective local and systemic resistance against B. cinerea.

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