Write 'systemic small RNAs': read 'systemic immunity'

2011 ◽  
Vol 38 (10) ◽  
pp. 747
Author(s):  
Alireza Seifi
Keyword(s):  
Gene Expression ◽  
Small Rnas ◽  
Rna Silencing ◽  
Mammalian Cells ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Plant Molecular Biology ◽  
Potential Contribution ◽  
Systemic Immunity

About 50 years ago, it was reported that pathogen-infected plants are less susceptible to a broad spectrum of the subsequent pathogen attacks. This form of induced resistance, which resembles the immunisation in mammalian cells, is called systemic acquired resistance (SAR). In the last 10 years, plant molecular biology has been revolutionised by the discovery of RNA silencing, which is also a systemic phenomenon and also contributes to plant immunity. Here, I review these two systemic phenomena in a comparative way to highlight the possibility that systemic silencing contributes to systemic immunity. This potential contribution could be in the process of gene expression reprogramming, which is needed for SAR induction, and/or in SAR signal complex, and/or in establishing SAR in remote tissues and forming priming status.

scholarly journals Extracellular pyridine nucleotides trigger plant systemic immunity through a lectin receptor kinase/BAK1 complex

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Chenggang Wang ◽  
Xiaoen Huang ◽  
Qi Li ◽  
Yanping Zhang ◽  
Jian-Liang Li ◽  
...  
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Receptor Complex ◽  
Pyridine Nucleotides ◽  
Receptor Kinase ◽  
Systemic Immunity ◽  
Lectin Receptor

Abstract Systemic acquired resistance (SAR) is a long-lasting broad-spectrum plant immunity induced by mobile signals produced in the local leaves where the initial infection occurs. Although multiple structurally unrelated signals have been proposed, the mechanisms responsible for perception of these signals in the systemic leaves are unknown. Here, we show that exogenously applied nicotinamide adenine dinucleotide (NAD+) moves systemically and induces systemic immunity. We demonstrate that the lectin receptor kinase (LecRK), LecRK-VI.2, is a potential receptor for extracellular NAD+ (eNAD+) and NAD+ phosphate (eNADP+) and plays a central role in biological induction of SAR. LecRK-VI.2 constitutively associates with BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1) in vivo. Furthermore, BAK1 and its homolog BAK1-LIKE1 are required for eNAD(P)+ signaling and SAR, and the kinase activities of LecR-VI.2 and BAK1 are indispensable to their function in SAR. Our results indicate that eNAD+ is a putative mobile signal, which triggers SAR through its receptor complex LecRK-VI.2/BAK1 in Arabidopsis thaliana.

scholarly journals Transcription Factors as the “Blitzkrieg” of Plant Defense: A Pragmatic View of Nitric Oxide’s Role in Gene Regulation

2021 ◽  
Vol 22 (2) ◽  
pp. 522
Author(s):  
Noreen Falak ◽  
Qari Muhammad Imran ◽  
Adil Hussain ◽  
Byung-Wook Yun
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Plant Defense ◽  
Systemic Acquired Resistance ◽  
Defense Mechanism ◽  
Regulation Of Gene Expression ◽  
Acquired Resistance ◽  
Biological Processes ◽  
Genetic Components ◽  
Transcriptional Changes

Plants are in continuous conflict with the environmental constraints and their sessile nature demands a fine-tuned, well-designed defense mechanism that can cope with a multitude of biotic and abiotic assaults. Therefore, plants have developed innate immunity, R-gene-mediated resistance, and systemic acquired resistance to ensure their survival. Transcription factors (TFs) are among the most important genetic components for the regulation of gene expression and several other biological processes. They bind to specific sequences in the DNA called transcription factor binding sites (TFBSs) that are present in the regulatory regions of genes. Depending on the environmental conditions, TFs can either enhance or suppress transcriptional processes. In the last couple of decades, nitric oxide (NO) emerged as a crucial molecule for signaling and regulating biological processes. Here, we have overviewed the plant defense system, the role of TFs in mediating the defense response, and that how NO can manipulate transcriptional changes including direct post-translational modifications of TFs. We also propose that NO might regulate gene expression by regulating the recruitment of RNA polymerase during transcription.

scholarly journals NPR1 and Redox Rhythmx: Connections, between Circadian Clock and Plant Immunity

2019 ◽  
Vol 20 (5) ◽  
pp. 1211 ◽  
Author(s):  
Jingjing Zhang ◽  
Ziyu Ren ◽  
Yuqing Zhou ◽  
Zheng Ma ◽  
Yanqin Ma ◽  
...  
Keyword(s):  
Circadian Clock ◽  
Systemic Acquired Resistance ◽  
Nuclear Translocation ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Defense Responses ◽  
Diurnal Changes ◽  
Pr Genes ◽  
Pathogen Infection ◽  
Physiological Reactions

The circadian clock in plants synchronizes biological processes that display cyclic 24-h oscillation based on metabolic and physiological reactions. This clock is a precise timekeeping system, that helps anticipate diurnal changes; e.g., expression levels of clock-related genes move in synchrony with changes in pathogen infection and help prepare appropriate defense responses in advance. Salicylic acid (SA) is a plant hormone and immune signal involved in systemic acquired resistance (SAR)-mediated defense responses. SA signaling induces cellular redox changes, and degradation and rhythmic nuclear translocation of the non-expresser of PR genes 1 (NPR1) protein. Recent studies demonstrate the ability of the circadian clock to predict various potential attackers, and of redox signaling to determine appropriate defense against pathogen infection. Interaction of the circadian clock with redox rhythm promotes the balance between immunity and growth. We review here a variety of recent evidence for the intricate relationship between circadian clock and plant immune response, with a focus on the roles of redox rhythm and NPR1 in the circadian clock and plant immunity.

Induction of gene expression for systemic acquired resistance in tobacco by 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (KODA)

2013 ◽  
Vol 93 (5) ◽  
pp. 827-830
Author(s):  
Jyun-ichi Endo ◽  
Wataru Takahashi ◽  
Mineyuki Yokoyama ◽  
Osamu Tanaka
Keyword(s):  
Gene Expression ◽  
Nicotiana Tabacum ◽  
Systemic Acquired Resistance ◽  
Octadecadienoic Acid ◽  
Acquired Resistance ◽  
Lemna Paucicostata

Endo, J., Takahashi, W., Yokoyama, M. and Tanaka, O. 2013. Induction of gene expression for systemic acquired resistance in tobacco by 9-hydroxy-10-oxo-12( Z ),15( Z )-octadecadienoic acid (KODA). Can. Plant Sci. 93: 827–830. The reaction of 9-hydroxy-10-oxo-12(Z),15(Z)-octadecadienoic acid (KODA) with (–)-norepinephrine (NE) generates the flowering inducer FN1 of duckweed Lemna paucicostata, although KODA and NE themselves do not promote flowering. We examined the effects of FN1, KODA, and NE on the induction of gene expression for systemic acquired resistance (SAR) in tobacco (Nicotiana tabacum) leaves and found that KODA induces the expression of SAR related genes.

scholarly journals rgs-CaM Detects and Counteracts Viral RNA Silencing Suppressors in Plant Immune Priming

2017 ◽  
Vol 91 (19) ◽  
Author(s):  
Eun Jin Jeon ◽  
Kazuki Tadamura ◽  
Taiki Murakami ◽  
Jun-ichi Inaba ◽  
Bo Min Kim ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Virus Infection ◽  
Virulence Factor ◽  
Rna Silencing ◽  
Systemic Acquired Resistance ◽  
Secondary Infection ◽  
Acquired Resistance ◽  
Tobacco Plants ◽  
Enhanced Resistance ◽  
Salicylic Acid Signaling

ABSTRACT Primary infection of a plant with a pathogen that causes high accumulation of salicylic acid in the plant typically via a hypersensitive response confers enhanced resistance against secondary infection with a broad spectrum of pathogens, including viruses. This phenomenon is called systemic acquired resistance (SAR), which is a plant priming for adaption to repeated biotic stress. However, the molecular mechanisms of SAR-mediated enhanced inhibition, especially of virus infection, remain unclear. Here, we show that SAR against cucumber mosaic virus (CMV) in tobacco plants (Nicotiana tabacum) involves a calmodulin-like protein, rgs-CaM. We previously reported the antiviral function of rgs-CaM, which binds to and directs degradation of viral RNA silencing suppressors (RSSs), including CMV 2b, via autophagy. We found that rgs-CaM-mediated immunity is ineffective against CMV infection in normally growing tobacco plants but is activated as a result of SAR induction via salicylic acid signaling. We then analyzed the effect of overexpression of rgs-CaM on salicylic acid signaling. Overexpressed and ectopically expressed rgs-CaM induced defense reactions, including cell death, generation of reactive oxygen species, and salicylic acid signaling. Further analysis using a combination of the salicylic acid analogue benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) and the Ca2+ ionophore A23187 revealed that rgs-CaM functions as an immune receptor that induces salicylic acid signaling by simultaneously perceiving both viral RSS and Ca2+ influx as infection cues, implying its autoactivation. Thus, secondary infection of SAR-induced tobacco plants with CMV seems to be effectively inhibited through 2b recognition and degradation by rgs-CaM, leading to reinforcement of antiviral RNA silencing and other salicylic acid-mediated antiviral responses. IMPORTANCE Even without an acquired immune system like that in vertebrates, plants show enhanced whole-plant resistance against secondary infection with pathogens; this so-called systemic acquired resistance (SAR) has been known for more than half a century and continues to be extensively studied. SAR-induced plants strongly and rapidly express a number of antibiotics and pathogenesis-related proteins targeted against secondary infection, which can account for enhanced resistance against bacterial and fungal pathogens but are not thought to control viral infection. This study showed that enhanced resistance against cucumber mosaic virus is caused by a tobacco calmodulin-like protein, rgs-CaM, which detects and counteracts the major viral virulence factor (RNA silencing suppressor) after SAR induction. rgs-CaM-mediated SAR illustrates the growth versus defense trade-off in plants, as it targets the major virulence factor only under specific biotic stress conditions, thus avoiding the cost of constitutive activation while reducing the damage from virus infection.

scholarly journals Induce the plant resistance to pathogen infection

2014 ◽  
Vol 20 (1-2) ◽  
Author(s):  
A. Ezzat ◽  
Z. Szabó ◽  
J. Nyéki
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Systemic Acquired Resistance ◽  
Induced Defense ◽  
Acquired Resistance ◽  
Vital Role ◽  
Signal Molecule ◽  
Pathogenesis Related ◽  
Related Proteins ◽  
Direct Toxicity

Systemic acquired resistance (SAR) is a mechanism of induced defense that confers long-lasting protection against a broad spectrum of microorganisms. Salicylic acid (SA) is the signal molecule which is required for induce SAR and is associated with accumulation of pathogenesis-related proteins, which are thought to contribute to resistance. SA paly vital role in some related resistance gene expression in plant cell which have direct or indirect effect on pathogen growth as SA has direct toxicity for pathogen and in the same time has stimulation effect for some enzyme related to reduce the oxidative burst.

scholarly journals The glycosyltransferase UGT76B1 is critical for plant immunity as it governs the homeostasis of N-hydroxy-pipecolic acid

2020 ◽  
Author(s):  
Lennart Mohnike ◽  
Dmitrij Rekhter ◽  
Weijie Huang ◽  
Kirstin Feussner ◽  
Hainan Tian ◽  
...  
Keyword(s):  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Pipecolic Acid ◽  
Balance Growth ◽  
Loss Of Function ◽  
Long Distance ◽  
Knock Out ◽  
Endogenous Substrates ◽  
Mutant Lines

AbstractThe trade-off between growth and defense is a critical aspect of plant immunity. Therefore, plant immune response needs to be tightly regulated. The hormone regulating plant defense against biotrophic pathogens is salicylic acid (SA). Recently, N-hydroxy-pipecolic acid (NHP) was identified as second regulator for plant innate immunity and systemic acquired resistance. Although the biosynthetic pathway leading to NHP formation has already been identified, the route how NHP is further metabolized was unclear. Here, we present UGT76B1 as a UDP-dependent glycosyltransferase that modifies NHP by catalyzing the formation of 1-O-glucosyl-pipecolic acid (NHP-OGlc). Analysis of T-DNA and CRISPR knock-out mutant lines of UGT76B1 by targeted and non-targeted UHPLC-HRMS underlined NHP and SA as endogenous substrates of this enzyme in response to Pseudomonas infection and UV treatment. UGT76B1 shows similar KM for NHP and SA. ugt76b1 mutant plants have a dwarf phenotype and a constitutive defense response which can be suppressed by loss of function of the NHP biosynthetic enzyme FMO1. This suggests that elevated accumulation of NHP contributes to the enhanced disease resistance in ugt76b1. Externally applied NHP can move to distal tissue in ugt76b1 mutant plants. Although glycosylation is not required for the long distance movement of NHP during systemic acquired resistance, it is crucial to balance growth and defense.

scholarly journals Physiologically relevant miRNAs in mammalian oocytes are rare and highly abundant.

2021 ◽  
Author(s):  
Shubhangini Kataruka ◽  
Veronika Kinterova ◽  
Filip Horvat ◽  
Jiri Kanka ◽  
Petr Svoboda
Keyword(s):  
Gene Expression ◽  
Small Rnas ◽  
Mammalian Cells ◽  
Negative Regulators ◽  
Oocyte Growth ◽  
Maternal To Zygotic Transition ◽  
Porcine Oocyte ◽  
Mirna Pathway ◽  
Expression In Mammalian Cells ◽  
Cognate Mrnas

miRNAs, ~22nt small RNAs associated with Argonaute (AGO) proteins, are important negative regulators of gene expression in mammalian cells. However, mammalian maternal miRNAs show negligible repressive activity and the miRNA pathway is dispensable for oocytes and maternal-to-zygotic transition. The stoichiometric hypothesis proposed that this is caused by dilution of maternal miRNAs during oocyte growth. As the dilution affects miRNAs but not mRNAs, it creates unfavorable miRNA:mRNA stoichiometry for efficient repression of cognate mRNAs. Here we report that porcine ssc-miR-205 and bovine bta-miR-10b are exceptional miRNAs, which resist the diluting effect of oocyte growth and can efficiently suppress gene expression. Additional analysis of ssc-miR-205 shows that it has higher stability, reduces expression of endogenous targets, and contributes to porcine oocyte-to-embryo transition. Consistent with the stoichiometric hypothesis, our results show that the endogenous miRNA pathway in mammalian oocytes is intact and that maternal miRNAs can efficiently suppress gene expression when a favorable miRNA:mRNA stoichiometry is established.

Taking Advantage of Plant Defense Mechanisms to Promote Human Health. The Plant Immune System. First of Two Parts

2020 ◽  
Vol 20 ◽  
Author(s):  
Thea Magrone ◽  
Manrico Magrone ◽  
Matteo Antonio Russo ◽  
Emilio Jirillo
Keyword(s):  
Immune Response ◽  
Plant Defense ◽  
Defense Mechanisms ◽  
Systemic Acquired Resistance ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Early Response ◽  
Protein Receptors ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Background: Despite the evidence that plants do not possess sessile cells, they are able to mount a vigorous immune response against invaders or under stressful conditions. Mechanisms of action: Plants are endowed with pattern recognition receptors (PPRs) which perceive damage-associated molecular patterns and microbe-associated molecular patterns or pathogen-associated molecular patterns (PAMPs), respectively. PPR activation leads to either the initiation of PAMP-triggered immunity (PTI) (early response) or the effectortriggered immunity (ETI). Both PTI and ETI contribute to plant systemic acquired resistance as also an expression of immunological memory or trained immunity. Plant immune receptors: PTI is initiated by activation of both receptor-like kinases and receptor-like proteins, while ETI depends on nucleotide-binding leucine-rich-repeat protein receptors for microbe recognition. Peptides involved in plant defenses: Plant chloroplasts contribute to both PTI and ETI through production of peptides which act as hormones or phytocytokines. Salicylic acid, jasmonic acid and ethylene are the major compounds involved in plant defense. Specific aims: The interaction between plant receptors and/or their products and bacterial components will be discussed. Also emphasis will be placed on plant microbiome for its contribution to plant immune response. Finally, the mutual interplay between insects and plants will also be illustrated. Conclusion: A better knowledge on plant immunity may pave the way for the exploitation of plant derivatives in the field of agriculture and medicine, as well.

Salicylic Acid: Biosynthesis and Signaling

2021 ◽  
Vol 72 (1) ◽  
Author(s):  
Yujun Peng ◽  
Jianfei Yang ◽  
Xin Li ◽  
Yuelin Zhang
Keyword(s):  
Salicylic Acid ◽  
Systemic Acquired Resistance ◽  
Current Knowledge ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Annual Review ◽  
Publication Date ◽  
Basal Defense ◽  
Made In ◽  
Key Questions

Salicylic acid (SA) is an essential plant defense hormone that promotes immunity against biotrophic and semibiotrophic pathogens. It plays crucial roles in basal defense and the amplification of local immune responses, as well as the establishment of systemic acquired resistance. During the past three decades, immense progress has been made in understanding the biosynthesis, homeostasis, perception, and functions of SA. This review summarizes the current knowledge regarding SA in plant immunity and other biological processes. We highlight recent breakthroughs that substantially advanced our understanding of how SA is biosynthesized from isochorismate, how it is perceived, and how SA receptors regulate different aspects of plant immunity. Some key questions in SA biosynthesis and signaling, such as how SA is produced via another intermediate benzoic acid and how SA affects the activities of its receptors in the transcriptional regulation of defense genes, remain to be addressed. Expected final online publication date for the Annual Review of Plant Biology, Volume 72 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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