scholarly journals Redox‐active cysteines in TGACG‐BINDING FACTOR 1 (TGA1) do not play a role in salicylic acid or pathogen‐induced expression of TGA1‐regulated target genes in Arabidopsis thaliana

2020 ◽  
Author(s):  
Jelena Budimir ◽  
Katrin Treffon ◽  
Aswin Nair ◽  
Corinnna Thurow ◽  
Christiane Gatz
Keyword(s):  
Arabidopsis Thaliana ◽  
Salicylic Acid ◽  
Target Genes ◽  
Induced Expression ◽  
Redox Active ◽  
Binding Factor

scholarly journals Redox-active cysteines in TGACG-BINDING FACTOR 1 (TGA1) do not play a role in salicylic acid- or pathogen-induced expression of TGA1-regulated target genes in Arabidopsis thaliana

2020 ◽  
Author(s):  
Jelena Budimir ◽  
Katrin Treffon ◽  
Aswin Nair ◽  
Corinna Thurow ◽  
Christiane Gatz
Keyword(s):  
Salicylic Acid ◽  
Systemic Acquired Resistance ◽  
Target Genes ◽  
Acquired Resistance ◽  
Signaling Cascade ◽  
List Type ◽  
Dependent Manner ◽  
Redox Active ◽  
Binding Factor ◽  
Pathogenesis Related

SummarySalicylic acid (SA) is an important signaling molecule of the plant immune system.SA biosynthesis is indirectly modulated by the closely related transcription factors TGA1 (TGACG-BINDING FACTOR 1) and TGA4. They activate expression of SARD1 (SYSTEMIC ACQUIRED RESISTANCE DEFICIENT1), the gene product of which regulates the key SA biosynthesis gene ICS1 (ISOCHORISMATE SYNTHASE 1).Since TGA1 interacts with the SA receptor NPR1 (NON EXPRESSOR OF PATHOGENESIS-RELATED GENES 1) in a redox-dependent manner and since the redox state of TGA1 is altered in SA-treated plants, TGA1 was assumed to play a role in the NPR1-dependent signaling cascade. Here we identified 193 out of 2090 SA-induced genes that require TGA1/TGA4 for maximal expression after SA treatment. One robustly TGA1/TGA4-dependent gene encodes for the SA hydroxylase DLO1 (DOWNY MILDEW RESISTANT 6-LIKE OXYGENASE 1) suggesting an additional regulatory role of TGA1/TGA4 in SA catabolism.Expression of TGA1/TGA4-dependent genes in mock/SA-treated or Pseudomonas-infected plants was rescued in the tga1 tga4 double mutant after introduction of a mutant genomic TGA1 fragment encoding a TGA1 protein without any cysteines. Thus, the functional significance of the observed redox modification of TGA1 in SA-treated tissues has remained enigmatic.SIGNIFICANCE STATEMENTPrevious findings demonstrating a redox-dependent interaction between transcription factor TGA1 and NPR1 attracted considerable attention. Here we show that TGA1 can act in the NPR1- and SA-dependent signaling cascade, but that its SA-regulated redox-active cysteines do not affect its function in this process.

scholarly journals Synthetic hormone-responsive transcription factors can monitor and re-program plant development

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Arjun Khakhar ◽  
Alexander R Leydon ◽  
Andrew C Lemmex ◽  
Eric Klavins ◽  
Jennifer L Nemhauser
Keyword(s):  
Arabidopsis Thaliana ◽  
Transcription Factors ◽  
Mathematical Models ◽  
Plant Development ◽  
Target Genes ◽  
Plant Morphology ◽  
Shoot Branching ◽  
Exogenous Hormone ◽  
Induced Expression ◽  
Auxin Transporter

Developmental programs sculpt plant morphology to meet environmental challenges, and these same programs have been manipulated to increase agricultural productivity (Doebley et al., 1997; Khush, 2001). Hormones coordinate these programs, creating chemical circuitry (Vanstraelen and Benková, 2012) that has been represented in mathematical models (Refahi et al., 2016; Prusinkiewicz et al., 2009); however, model-guided engineering of plant morphology has been limited by a lack of tools (Parry et al., 2009; Voytas and Gao, 2014). Here, we introduce a novel set of synthetic and modular hormone activated Cas9-based repressors (HACRs) in Arabidopsis thaliana that respond to three hormones: auxin, gibberellins and jasmonates. We demonstrate that HACRs are sensitive to both exogenous hormone treatments and local differences in endogenous hormone levels associated with development. We further show that this capability can be leveraged to reprogram development in an agriculturally relevant manner by changing how the hormonal circuitry regulates target genes. By deploying a HACR to re-parameterize the auxin-induced expression of the auxin transporter PIN-FORMED1 (PIN1), we decreased shoot branching and phyllotactic noise, as predicted by existing models (Refahi et al., 2016; Prusinkiewicz et al., 2009).

scholarly journals Down Regulation of Virulence Factors of Pseudomonas aeruginosa by Salicylic Acid Attenuates Its Virulence on Arabidopsis thaliana and Caenorhabditis elegans

2005 ◽  
Vol 73 (9) ◽  
pp. 5319-5328 ◽  
Author(s):  
B. Prithiviraj ◽  
H. P. Bais ◽  
T. Weir ◽  
B. Suresh ◽  
E. H. Najarro ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Arabidopsis Thaliana ◽  
Salicylic Acid ◽  
Plant Defense ◽  
Virulence Factors ◽  
Target Genes ◽  
Defense Responses ◽  
Infection Model ◽  
Plant Defense Responses ◽  
Wild Type

ABSTRACT Salicylic acid (SA) is a phenolic metabolite produced by plants and is known to play an important role in several physiological processes, such as the induction of plant defense responses against pathogen attack. Here, using the Arabidopsis thaliana-Pseudomonas aeruginosa pathosystem, we provide evidence that SA acts directly on the pathogen, down regulating fitness and virulence factor production of the bacteria. Pseudomonas aeruginosa PA14 showed reduced attachment and biofilm formation on the roots of the Arabidopsis mutants lox2 and cpr5-2, which produce elevated amounts of SA, as well as on wild-type Arabidopsis plants primed with exogenous SA, a treatment known to enhance endogenous SA concentration. Salicylic acid at a concentration that did not inhibit PA14 growth was sufficient to significantly affect the ability of the bacteria to attach and form biofilm communities on abiotic surfaces. Furthermore, SA down regulated three known virulence factors of PA14: pyocyanin, protease, and elastase. Interestingly, P. aeruginosa produced more pyocyanin when infiltrated into leaves of the Arabidopsis transgenic line NahG, which accumulates less SA than wild-type plants. This finding suggests that endogenous SA plays a role in down regulating the synthesis and secretion of pyocyanin in vivo. To further test if SA directly affects the virulence of P. aeruginosa, we used the Caenorhabiditis elegans-P. aeruginosa infection model. The addition of SA to P. aeruginosa lawns significantly diminished the bacterium's ability to kill the worms, without affecting the accumulation of bacteria inside the nematodes' guts, suggesting that SA negatively affects factors that influence the virulence of P. aeruginosa. We employed microarray technology to identify SA target genes. These analyses showed that SA treatment affected expression of 331 genes. It selectively repressed transcription of exoproteins and other virulence factors, while it had no effect on expression of housekeeping genes. Our results indicate that in addition to its role as a signal molecule in plant defense responses, SA works as an anti-infective compound by affecting the physiology of P. aeruginosa and ultimately attenuating its virulence.

Cryptotanshinone Suppresses Liver Fibrosis by Attenuating Epithelial-Mesenchymal Transition through Targeting Hedgehog Pathway

2020 ◽  
Vol 20 ◽  
Author(s):  
Shurong Ren ◽  
Qizhen Yue ◽  
Qiubo Wang ◽  
Yanli Zhang ◽  
Bei Zhang
Keyword(s):  
Animal Model ◽  
Liver Fibrosis ◽  
Liver Diseases ◽  
Target Genes ◽  
Epithelial Mesenchymal Transition ◽  
Chronic Liver ◽  
Luciferase Assay ◽  
Induced Expression ◽  
Mesenchymal Transition ◽  
Realtime Pcr

Background: Chronic liver damages from viral infection or alcohol abuse result in liver fibrosis, which is a key pathological event in many types of liver diseases. Discovering new anti-fibrosis agents may provide alternative solutions to manage chronic liver diseases. Methods: We first used CCl4 induced liver fibrosis animal model to evaluate the beneficial effects of Cryptotanshinone (CRY). We next explored target miRNAs regulated by CRY in hepatocytes using microarray. The target miRNA candidate was confirmed with realtime-PCR. We also elucidated the downstream target and pathway directly regulated by the miRNA using luciferase assay, western blotting and Epithelial–Mesenchymal Transition (EMT) markers quantification. Lastly, we confirmed CRY induced expression changes of the target genes in vivo. Results: CRY oral administration markedly alleviated the liver injury caused by CCl4. miRNAs expression profiling and realtime-PCR validation revealed miR-539-3p was directly induced by CRY around 4 folds. The induction of miR-539-3p suppressed SMO expression and antagonized Hedgehog (Hh) pathway. Independently CRY treatment suppressed SMO and inhibited EMT process in hepatocytes. The CRY induced expression changes of both miR-539-3p (~ 2 folds increase) and SMO (~ 60% decrease) in livers were validated in animal model. Conclusion: Our study supported CRY could inhibit liver fibrosis by targeting Hh pathway during EMT. CRY could be used as anti-fibrosis agent candidate for managing chronic liver damages.

scholarly journals Alternative splicing landscapes in Arabidopsis thaliana across tissues and stress conditions highlight major functional differences with animals

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Guiomar Martín ◽  
Yamile Márquez ◽  
Federica Mantica ◽  
Paula Duque ◽  
Manuel Irimia
Keyword(s):  
Gene Expression ◽  
Arabidopsis Thaliana ◽  
Alternative Splicing ◽  
Stress Responses ◽  
Target Genes ◽  
Intron Retention ◽  
Single Gene ◽  
Exon Skipping ◽  
Environmental Response ◽  
Biotic Stresses

Abstract Background Alternative splicing (AS) is a widespread regulatory mechanism in multicellular organisms. Numerous transcriptomic and single-gene studies in plants have investigated AS in response to specific conditions, especially environmental stress, unveiling substantial amounts of intron retention that modulate gene expression. However, a comprehensive study contrasting stress-response and tissue-specific AS patterns and directly comparing them with those of animal models is still missing. Results We generate a massive resource for Arabidopsis thaliana, PastDB, comprising AS and gene expression quantifications across tissues, development and environmental conditions, including abiotic and biotic stresses. Harmonized analysis of these datasets reveals that A. thaliana shows high levels of AS, similar to fruitflies, and that, compared to animals, disproportionately uses AS for stress responses. We identify core sets of genes regulated specifically by either AS or transcription upon stresses or among tissues, a regulatory specialization that is tightly mirrored by the genomic features of these genes. Unexpectedly, non-intron retention events, including exon skipping, are overrepresented across regulated AS sets in A. thaliana, being also largely involved in modulating gene expression through NMD and uORF inclusion. Conclusions Non-intron retention events have likely been functionally underrated in plants. AS constitutes a distinct regulatory layer controlling gene expression upon internal and external stimuli whose target genes and master regulators are hardwired at the genomic level to specifically undergo post-transcriptional regulation. Given the higher relevance of AS in the response to different stresses when compared to animals, this molecular hardwiring is likely required for a proper environmental response in A. thaliana.

scholarly journals The EAR Motif in the Arabidopsis MADS Transcription Factor AGAMOUS-Like 15 Is Not Necessary to Promote Somatic Embryogenesis

Plants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 758
Author(s):  
Sanjay Joshi ◽  
Christian Keller ◽  
Sharyn E. Perry
Keyword(s):  
Gene Expression ◽  
Somatic Embryogenesis ◽  
Target Gene ◽  
Target Genes ◽  
Domain Family ◽  
Binding Factor ◽  
Ear Motif ◽  
Carboxyl Terminal ◽  
Responsive Element ◽  
Carboxy Terminal

AGAMOUS-like 15 (AGL15) is a member of the MADS domain family of transcription factors (TFs) that can directly induce and repress target gene expression, and for which promotion of somatic embryogenesis (SE) is positively correlated with accumulation. An ethylene-responsive element binding factor-associated amphiphilic repression (EAR) motif of form LxLxL within the carboxyl-terminal domain of AGL15 was shown to be involved in repression of gene expression. Here, we examine whether AGL15′s ability to repress gene expression is needed to promote SE. While a form of AGL15 where the LxLxL is changed to AxAxA can still promote SE, another form with a strong transcriptional activator at the carboxy-terminal end, does not promote SE and, in fact, is detrimental to SE development. Select target genes were examined for response to the different forms of AGL15.

scholarly journals Arabidopsis thaliana cdd1 mutant uncouples the constitutive activation of salicylic acid signalling from growth defects

2011 ◽  
Vol 12 (9) ◽  
pp. 855-865 ◽  
Author(s):  
SWADHIN SWAIN ◽  
SHWETA ROY ◽  
JYOTI SHAH ◽  
SASKIA VAN WEES ◽  
CORNÉ M. PIETERSE ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Salicylic Acid ◽  
Constitutive Activation ◽  
Growth Defects
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