scholarly journals Phytosphingosine induces systemic acquired resistance through activation of sphingosine kinase

2020 ◽  
Author(s):  
So Yeon Seo ◽  
Yu Jung Kim ◽  
Myung Hee Nam ◽  
Ky Young Park
Keyword(s):  
Systemic Acquired Resistance ◽  
De Novo ◽  
Cell Damage ◽  
Plant Immunity ◽  
Acquired Resistance ◽  
Signaling Molecules ◽  
Dependent Manner ◽  
Serine Palmitoyltransferase ◽  
Exogenous Addition ◽  
Sphingolipid Biosynthesis

AbstractPhytosphingosine (PHS) is a naturally occurring bioactive sphingolipid molecule. Intermediates such as sphingolipid long-chain bases (LCBs) in sphingolipid biosynthesis have been shown to have important roles as signaling molecules. In this study, exogenous addition of PHS caused rapid induction of transcripts responsible for transient synthesis of LCBs, reactive oxygen species, and ethylene. These events were followed by the induction of sphingolipid kinase (SphK), which metabolized PHS to phytosphingosine-1-phosphate in an biphasic manner. PHS alleviated not only pathogen-induced cell damage but also reduced the growth of virulent pathogens in the entire upper part of the PHS-treated plant stem during the necrotic stage after inoculation, suggesting the development of systemic acquired resistance (SAR) and plant immunity. Moreover, PHS treatment up-regulated the transcription and activity of SphK, accompanied by prominent increases in the transcription levels of serine palmitoyltransferase (LCB1 and LCB2) for de novo synthesis of sphingolipids, as well as ROS-detoxifying enzymes and PR proteins at 48 h after virulent pathogen infection. The impairment of ROS production at this time is more beneficial for the activation of SphK and inhibition of pathogenicity during the necrotic stage of hemibiotrophic infection, indicating that necrotic cell death at the late stage is regulated by ROS-independent SphK. Phosphorylated LCBs significantly reduced pathogen-induced cell damage. These observations suggest that selective channeling of sphingolipids into phosphorylated forms in a time-dependent manner has a pro-survival effect by promoting SAR in plant immunity.4.One Sentence SummarySelective gene expression in sphingolipid biosynthesis and channeling into their phosphorylated forms are significant determinants of their roles as pro-survival signaling molecules.

Regulation of de novo sphingolipid biosynthesis and the toxic consequences of its disruption

2001 ◽  
Vol 29 (6) ◽  
pp. 831-835 ◽  
Author(s):  
S. C. Linn ◽  
H. S. Kim ◽  
E. M. Keane ◽  
L. M. Andras ◽  
E. Wang ◽  
...  
Keyword(s):  
De Novo ◽  
Uv Light ◽  
Wide Spectrum ◽  
Sphingolipid Metabolism ◽  
Intrinsic Activity ◽  
Type I ◽  
Serine Palmitoyltransferase ◽  
Post Translational Modification ◽  
Sphingolipid Biosynthesis ◽  
Complex Sphingolipids

Complex sphingolipids are ‘built’ on highly bio-active backbones (sphingoid bases and ceramides) that can cause cell death when the amounts are elevated by turnover of complex sphingolipids, disruption of normal sphingolipid metabolism, or over-induction of sphingolipid biosynthesis de novo. Under normal conditions, it appears that the bioactive intermediates of this pathway (3-keto-sphinganine, sphinganine and ceramides) are kept at relatively low levels. Both the intrinsic activity of serine palmitoyltransferase (SPT) and the availability of its substrates (especially palmitoyl-CoA) can have toxic consequences for cells by increasing the production of cytotoxic intermediates. Recent work has also revealed that diverse agonists and stresses (cytokines, UV light, glucocorticoids, heat shock and toxic compounds) modulate SPT activity by induction of SPTLC2 gene transcription and/or post-translational modification. Mutation of the SPTLC1 component of SPT has also been shown to cause hereditary sensory neuropathy type I, possibly via aberrant oversynthesis of sphingolipids. Another key step of the pathway is the acylation of sphinganine (and sphingosine in the recycling pathway) by ceramide synthase, and up-regulation of this enzyme (or its inhibition to cause accumulation of sphinganine) can also be toxic for cells. Since it appears that most, if not all, tissues synthesize sphingolipids de novo, it may not be surprising that disruption of this pathway has been implicated in a wide spectrum of disease.

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 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.

scholarly journals Crassaostrea gigas Oyster Shell Extract Inhibits Lipogenesis via Suppression of Serine Palmitoyltransferase

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000
Author(s):  
Nguyen Khoi Song Tran ◽  
Jeong Eun Kwon ◽  
Se Chan Kang ◽  
Soon-Mi Shim ◽  
Tae-Sik Park
Keyword(s):  
De Novo ◽  
Preventive Measure ◽  
Ethanol Extract ◽  
Oyster Shell ◽  
Lipid Lowering ◽  
Metabolic Dysfunction ◽  
Serine Palmitoyltransferase ◽  
Lipogenic Gene Expression ◽  
Cholesterol Levels ◽  
Sphingolipid Biosynthesis

Oysters are widely consumed seafood, but their shells impose a serious environmental problem. To extend the utilization of oyster shell waste, we investigated the biological role of oyster shell extract. In this study, we verified that the ethanol extract of oyster shell (EOS) contains taurine and betaine, the major components of oyster body. EOS downregulated transcription of Sptlc1 and Sptlc2 mRNA, the subunits of serine palmitoyltransferase (SPT). Suppression of SPT subunits reduced sphinganine and sphingomyelin by inhibiting de novo sphingolipid biosynthesis. Inhibition of sphingomyelin biosynthesis resulted in downregulation of lipogenic gene expression such as ACC, FAS, SCD1, and DGAT2. Consistent with inhibition of lipogenesis, cellular triglyceride levels were diminished by EOS, but cholesterol levels were not altered. Taken together, these results suggest that EOS has a lipid-lowering effect and could be applied as either a therapeutic or preventive measure for metabolic dysfunction.

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.

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.

scholarly journals Viral serine palmitoyltransferase induces metabolic switch in sphingolipid biosynthesis and is required for infection of a marine alga

2016 ◽  
Vol 113 (13) ◽  
pp. E1907-E1916 ◽  
Author(s):  
Carmit Ziv ◽  
Sergey Malitsky ◽  
Alaa Othman ◽  
Shifra Ben-Dor ◽  
Yu Wei ◽  
...  
Keyword(s):  
De Novo ◽  
Serine Palmitoyltransferase ◽  
Metabolic Switch ◽  
Marine Viruses ◽  
Key Enzyme ◽  
Infected Cells ◽  
Biochemical Analyses ◽  
Biological Entities ◽  
Sphingolipid Biosynthesis

Marine viruses are the most abundant biological entities in the oceans shaping community structure and nutrient cycling. The interaction between the bloom-forming algaEmiliania huxleyiand its specific large dsDNA virus (EhV) is a major factor determining the fate of carbon in the ocean, thus serving as a key host-pathogen model system. The EhV genome encodes for a set of genes involved in the de novo sphingolipid biosynthesis, not reported in any viral genome to date. We combined detailed lipidomic and biochemical analyses to characterize the functional role of this virus-encoded pathway during lytic viral infection. We identified a major metabolic shift, mediated by differential substrate specificity of virus-encoded serine palmitoyltransferase, a key enzyme of sphingolipid biosynthesis. Consequently, unique viral glycosphingolipids, composed of unusual hydroxylated C17 sphingoid bases (t17:0) were highly enriched in the infected cells, and their synthesis was found to be essential for viral assembly. These findings uncover the biochemical bases of the virus-induced metabolic rewiring of the host sphingolipid biosynthesis during the chemical “arms race” in the ocean.

scholarly journals Polyphenol oxidase and lysozyme mediate induction of systemic resistance in tomato, when a bioelicitor is used

2015 ◽  
Vol 55 (4) ◽  
pp. 343-350 ◽  
Author(s):  
Navodit Goel ◽  
Prabir Kumar Paul
Keyword(s):  
Pseudomonas Syringae ◽  
Polyphenol Oxidase ◽  
Systemic Acquired Resistance ◽  
De Novo ◽  
Acquired Resistance ◽  
Crop Protection ◽  
Systemic Resistance ◽  
Neem Extract ◽  
Single Node ◽  
Protection Method

Abstract Tomato (Solanum lycopersicum L.) is attacked by Pseudomonas syringae pv. tomato causing heavy damage to the crops. The present study focused on the application of aqueous fruit extracts of neem (Azadirachta indica L.) on a single node of aseptically raised tomato plants. Observations were done, and the changes in the activity and isoenzyme profile of polyphenol oxidase (PPO) and lysozyme, both at the site of treatment as well as away from it, were noted. The results demonstrate that neem extract could significantly induce the activities of both the enzymes as well as upregulate the de novo expression of additional PPO isoenzymes. Induction of systemic acquired resistance (SAR) by natural plant extracts is a potent eco-friendly crop protection method.

scholarly journals HrpNEa Induces Chinese Cabbage Resistance to Bacterial Soft Rot by Inhibiting the Bacterial Attachment to Root Surfaces

Plant Disease ◽  
2010 ◽  
Vol 94 (12) ◽  
pp. 1441-1447 ◽  
Author(s):  
Lijun Sun ◽  
Xiaomeng Wang ◽  
Shuping Qu ◽  
Huimin Liu ◽  
Zhenhua Jia ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Chinese Cabbage ◽  
Systemic Acquired Resistance ◽  
Acquired Resistance ◽  
Soft Rot ◽  
Bacterial Attachment ◽  
Dependent Manner ◽  
Bacterial Soft Rot ◽  
Root Surfaces ◽  
Quorum Sensing Signals

HrpNEa is a harpin protein produced by the bacterial plant pathogen Erwinia amylovora. When applied to aerial parts of plants, the protein induces systemic acquired resistance in a variety of plant species. Here, we report that treating Chinese cabbage roots with HrpNEa induces resistance of the plant to Pectobacterium carotovora subsp. carotovora, the pathogen that invades roots and causes bacterial soft rot in cruciferous plants. Treating Chinese cabbage roots with HrpNEa significantly decreased severities of soft rot symptoms on the plant. The root treatment decreased the number of P. carotovora subsp. carotovora cells attached to root surfaces and inhibited the ability of P. carotovora subsp. carotovora to produce quorum-sensing signals, which regulate pathogenicity in a bacterial population-dependent manner. The inhibitory effects of HrpNEa on the root attachment and quorum-sensing signals accompanied the induced expression of several defense response genes. These results suggest that HrpNEa induces Chinese cabbage resistance to bacterial soft rot by inhibiting the bacterial attachment to root surfaces.

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