scholarly journals Crosstalk between Calcium and ROS Signaling during Flg22-Triggered Immune Response in Arabidopsis Leaves

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 14
Author(s):  
Matthew J. Marcec ◽  
Kiwamu Tanaka
Keyword(s):  
Second Messengers ◽  
Cytosolic Calcium ◽  
Defense Responses ◽  
Calcium Signal ◽  
Pharmacological Agents ◽  
Ros Signaling ◽  
Molecular Pattern ◽  
Respiratory Burst Oxidase ◽  
Insight Into ◽  
Calcium Elevation

Calcium and reactive oxygen species (ROS) are two of the earliest second messengers in response to environmental stresses in plants. The rise and sequestration of these messengers in the cytosol and apoplast are formed by various channels, transporters, and enzymes that are required for proper defense responses. It remains unclear how calcium and ROS signals regulate each other during pattern-triggered immunity (PTI). In the present study, we examined the effects of perturbing one signal on the other in Arabidopsis leaves upon the addition of flg22, a well-studied microbe-associated molecular pattern (MAMP). To this end, a variety of pharmacological agents were used to suppress either calcium or ROS signaling. Our data suggest that cytosolic calcium elevation is required to initiate and regulate apoplastic ROS production generated by respiratory burst oxidase homologs (RBOHs). In contrast, ROS has no effect on the initiation of the calcium signal, but is required for forming a sufficient amplitude of the calcium signal. This finding using pharmacological agents is corroborated by the result of using a genetic double mutant, rbohd rbohf. Our study provides an insight into the mutual interplay of calcium and ROS signals during the MAMP-induced PTI response in plants.

scholarly journals Identification of Msp1-Induced Signaling Components in Rice Leaves by Integrated Proteomic and Phosphoproteomic Analysis

2019 ◽  
Vol 20 (17) ◽  
pp. 4135 ◽  
Author(s):  
Ravi Gupta ◽  
Cheol Woo Min ◽  
Yu-Jin Kim ◽  
Sun Tae Kim
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase ◽  
Defense Responses ◽  
Mitogen Activated Protein Kinase ◽  
Calcium Dependent ◽  
Molecular Pattern ◽  
Mitogen Activated Protein ◽  
Dependent Protein ◽  
Rice Leaves ◽  
Respiratory Burst Oxidase

MSP1 is a Magnaporthe oryzae secreted protein that elicits defense responses in rice. However, the molecular mechanism of MSP1 action is largely elusive. Moreover, it is yet to be established whether MSP1 functions as a pathogen-associated molecular pattern (PAMP) or an effector. Here, we employed a TMT-based quantitative proteomic analysis of cytosolic as well as plasma membrane proteins to decipher the MSP1 induced signaling in rice. This approach led to the identification of 6691 proteins, of which 3049 were identified in the plasma membrane (PM), while 3642 were identified in the cytosolic fraction. A parallel phosphoproteome analysis led to the identification of 1906 phosphopeptides, while the integration of proteome and phosphoproteome data showed activation of proteins related to the proteolysis, jasmonic acid biosynthesis, redox metabolism, and MAP kinase signaling pathways in response to MSP1 treatment. Further, MSP1 induced phosphorylation of some of the key proteins including respiratory burst oxidase homologue-D (RBOHD), mitogen-activated protein kinase kinase kinase-1 (MEKK1), mitogen-activated protein kinase-3/6 (MPK3/6), calcium-dependent protein kinase (CDPK) and calmodulin (CaM) suggest activation of PAMP-triggered immunity (PTI) in response to MSP1 treatment. In essence, our results further support the functioning of MSP1 as a PAMP and provide an overview of the MSP1 induced signaling in rice leaves.

scholarly journals Arabidopsis Toxicos en Levadura 12 (ATL12): A Gene Involved in Chitin-Induced, Hormone-Related and NADPH Oxidase-Mediated Defense Responses

2021 ◽  
Vol 7 (10) ◽  
pp. 883
Author(s):  
Feng Kong ◽  
Tingwei Guo ◽  
Katrina M. Ramonell
Keyword(s):  
Plasma Membrane ◽  
Nadph Oxidase ◽  
Model Organism ◽  
Defense Responses ◽  
Histochemical Staining ◽  
Fungal Cell ◽  
Mapk Cascades ◽  
Molecular Pattern ◽  
Golovinomyces Cichoracearum ◽  
Respiratory Burst Oxidase

Plants, as sessile organisms, have evolved complex systems to respond to changes in environmental conditions. Chitin is a Pathogen-Associated-Molecular Pattern (PAMP) that exists in the fungal cell walls, and can be recognized by plants and induce plant pattern-triggered immunity (PTI). Our previous studies showed that Arabidopsis Toxicos en Levadura 12 (ATL12) is highly induced in response to fungal infection and chitin treatment. We used the model organism Arabidopsis thaliana to characterize ATL12 and explore its role in fungal defense. Histochemical staining showed that pATL12-GUS was continually expressed in roots, leaves, stems, and flowers. Subcellular co-localization of the ATL12-GFP fusion protein with the plasma membrane-mcherry marker showed that ATL12 localizes to the plasma membrane. Mutants of atl12 are more susceptible to Golovinomyces cichoracearum infection, while overexpression of ATL12 increased plant resistance to the fungus. ATL12 is highly induced by chitin after two hours of treatment and ATL12 may act downstream of MAPK cascades. Additionally, 3,3′-diaminobenzidine (DAB) staining indicated that atl12 mutants generate less reactive oxygen species compared to wild-type Col-0 plants and RT-PCR indicated that ATL12-regulated ROS production may be linked to the expression of respiratory burst oxidase homolog protein D/F (AtRBOHD/F). Furthermore, we present evidence that ATL12 expression is upregulated after treatment with both salicylic acid and jasmonic acid. Taken together, these results suggest a role for ATL12 in crosstalk between hormonal, chitin-induced, and NADPH oxidase-mediated defense responses in Arabidopsis.

scholarly journals The Fungal Effector Avr-Pita Suppresses Innate Immunity by Increasing COX Activity in Rice Mitochondria

Rice ◽  
2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Jingluan Han ◽  
Xiaoyu Wang ◽  
Fengpin Wang ◽  
Zhe Zhao ◽  
Gousi Li ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Host Plant ◽  
Fungal Pathogen ◽  
Defense Responses ◽  
Oxygen Species ◽  
Mitochondrial Reactive Oxygen Species ◽  
Molecular Pattern ◽  
Ros Accumulation ◽  
Ros Metabolism ◽  
Increased Susceptibility

Abstract Background Avr-Pita was the first effector identified in the blast fungus (Magnaporthe oryzae)–rice (Oryza sativa) pathosystem. However, the molecular mechanism underlying its effects on the host plant has remained a long-standing mystery. Results Here, we report that ectopically expressing Avr-Pita in rice enhances susceptibility to M. oryzae and suppresses pathogen-associated molecular pattern (PAMP)-triggered defense responses. Avr-Pita targets the host mitochondria and interacts with the cytochrome c oxidase (COX) assembly protein OsCOX11, a key regulator of mitochondrial reactive oxygen species (ROS) metabolism in rice. Overexpressing Avr-Pita or OsCOX11 increased COX activity and decreased ROS accumulation triggered by the fungal PAMP chitin. OsCOX11-overexpressing plants showed increased susceptibility to M. oryzae, whereas OsCOX11-knockdown plants showed resistance to M. oryzae. Conclusions Taken together, these findings suggest that the fungal pathogen M. oryzae delivers the effector Avr-Pita to the host plant, where it enhances COX activity thus decreasing ROS accumulation. Therefore, this effector suppresses host innate immunity by perturbing ROS metabolism in the mitochondria.

scholarly journals Protection against hydrogen peroxide cytotoxicity in Rat-1 fibroblasts provided by the oncoprotein Bcl-2: maintenance of calcium homoeostasis is secondary to the effect of Bcl-2 on cellular glutathione

1999 ◽  
Vol 340 (1) ◽  
pp. 291-297 ◽  
Author(s):  
Matthäus M. RIMPLER ◽  
Ursula RAUEN ◽  
Thorsten SCHMIDT ◽  
Tarik MÖRÖY ◽  
Herbert DE GROOT
Keyword(s):  
Cell Death ◽  
Calcium Concentration ◽  
Cell Injury ◽  
Cytosolic Calcium ◽  
Glutathione Metabolism ◽  
Transfected Cells ◽  
Cytosolic Calcium Concentration ◽  
Glutathione Status ◽  
Calcium Elevation ◽  
Reduced State

The oncoprotein Bcl-2 protects cells against apoptosis, but the exact molecular mechanism that underlies this function has not yet been identified. Studying H2O2-induced cell injury in Rat-1 fibroblast cells, we observed that Bcl-2 had a protective effect against the increase in cytosolic calcium concentration and subsequent cell death. Furthermore, overexpression of Bcl-2 resulted in an alteration of cellular glutathione status: the total amount of cellular glutathione was increased by about 60% and the redox potential of the cellular glutathione pool was maintained in a more reduced state during H2O2 exposure compared with non-Bcl-2-expressing controls. In our cytotoxicity model, disruption of cellular glutathione homoeostasis closely correlated with the pathological elevation of cytosolic calcium concentration. Stabilization of the glutathione pool by Bcl-2, N-acetylcysteine or glucose delayed the cytosolic calcium increase and subsequent cell death, whereas depletion of glutathione by DL-buthionine-(S,R)-sulphoximine, sensitized Bcl-2-transfected cells towards cytosolic calcium increase and cell death. We therefore suggest that the protection exerted by Bcl-2 against H2O2-induced cytosolic calcium elevation and subsequent cell death is secondary to its effect on the cellular glutathione metabolism.

scholarly journals The calcium-dependent ATP-Mg/Pi mitochondrial carrier is a target of glucose-induced calcium signalling in Saccharomyces cerevisiae

2005 ◽  
Vol 392 (3) ◽  
pp. 537-544 ◽  
Author(s):  
Santiago Cavero ◽  
Javier Traba ◽  
Araceli Del Arco ◽  
Jorgina Satrústegui
Keyword(s):  
Calcium Binding ◽  
Mitochondrial Protein ◽  
Calcium Signalling ◽  
Cytosolic Calcium ◽  
Calcium Signal ◽  
Transport Activity ◽  
Wild Type ◽  
Binding Motifs ◽  
Mitochondrial Carrier ◽  
Calcium Dependent

Sal1p is a mitochondrial protein that belongs to the SCaMC (short calcium-binding mitochondrial carrier) subfamily of mitochondrial carriers. The presence of calcium-binding motifs facing the extramitochondrial space allows the regulation of the transport activity of these carriers by cytosolic calcium and provides a new mechanism to transduce calcium signals in mitochondria without the requirement of calcium entry in the organelle. We have studied its transport activity, finding that it is a carboxyatractyloside-resistant ATP-Mg carrier. Mitochondria from a disruption mutant of SAL1 have a 50% reduction in the uptake of ATP. We have also found a clear stimulation of ATP-transport activity by calcium, with an S0.5 of approx. 30 μM. Our results also suggest that Sal1p is a target of the glucose-induced calcium signal which is non-essential in wild-type cells, but becomes essential for transport of ATP into mitochondria in yeast lacking ADP/ATP translocases.

Discovery and Characterization of Differentially Expressed Soybean MiRNAs and Their Targets During Soybean Mosaic Virus Infection Unveils Novel Insight Into Soybean-SMV Interaction

2021 ◽  
Author(s):  
Bowen Li ◽  
Adhimoolam Karthikeyan ◽  
Liqun Wang ◽  
Jinlong Yin ◽  
Tongtong Jin ◽  
...  
Keyword(s):  
Virus Infection ◽  
Mosaic Virus ◽  
Target Genes ◽  
Soybean Mosaic Virus ◽  
Expression Patterns ◽  
Defense Responses ◽  
Pcr Analysis ◽  
Functional Annotations ◽  
Additional Information ◽  
Insight Into

Abstract Background: Soybean mosaic virus (SMV) is the most devastating pathogen of soybean. MicroRNAs (miRNAs) are a class of non-coding RNAs (21-24 nucleotides) and play important roles in regulating defense responses against pathogens. However, miRNA's response to SMV in soybean is not as well documented. Result: In this study, we analyzed 18 miRNA libraries, including three biological replicates from two soybean lines (Resistant and susceptible lines to SMV strain SC3 selected from the near-isogenic lines of Qihuang No. 1× Nannong1138-2) after virus infection at three different time intervals (0 dpi, 7 dpi, and 14 dpi). A total of 1,092 miRNAs, including 608 known miRNAs and 484 novel miRNAs were detected. Differential expression analyses identified the miRNAs responded during soybean-SMV interaction. Then, miRNAs potential target genes were predicted via data mining, and functional annotation was done by Gene Ontology (GO) analysis. Eventually, the expression patterns of several miRNAs validated by quantitative real-time PCR analysis are consistent with sequencing results. Conclusion: We have identified a large number of miRNAs and their target genes and also functional annotations. Our study provides additional information on soybean miRNAs and an insight into the role of miRNAs during SMV-infection in soybean.

scholarly journals Role of Ca2+ in Mediating Plant Responses to Extracellular ATP and ADP

2018 ◽  
Vol 19 (11) ◽  
pp. 3590 ◽  
Author(s):  
Greg Clark ◽  
Stanley Roux
Keyword(s):  
Cytosolic Calcium ◽  
Defense Responses ◽  
Receptor Activation ◽  
Extracellular Atp ◽  
Extracellular Nucleotides ◽  
Nucleoside Triphosphate ◽  
Plant Responses ◽  
Downstream Signaling ◽  
Nucleoside Triphosphate Diphosphohydrolase

Among the most recently discovered chemical regulators of plant growth and development are extracellular nucleotides, especially extracellular ATP (eATP) and extracellular ADP (eADP). Plant cells release ATP into their extracellular matrix under a variety of different circumstances, and this eATP can then function as an agonist that binds to a specific receptor and induces signaling changes, the earliest of which is an increase in the concentration of cytosolic calcium ([Ca2+]cyt). This initial change is then amplified into downstream-signaling changes that include increased levels of reactive oxygen species and nitric oxide, which ultimately lead to major changes in the growth rate, defense responses, and leaf stomatal apertures of plants. This review presents and discusses the evidence that links receptor activation to increased [Ca2+]cyt and, ultimately, to growth and diverse adaptive changes in plant development. It also discusses the evidence that increased [Ca2+]cyt also enhances the activity of apyrase (nucleoside triphosphate diphosphohydrolase) enzymes that function in multiple subcellular locales to hydrolyze ATP and ADP, and thus limit or terminate the effects of these potent regulators.

L-selectin stimulation of canine neutrophil initiates calcium signal secondary to tyrosine kinase activation

1997 ◽  
Vol 272 (3) ◽  
pp. H1302-H1308 ◽  
Author(s):  
E. Crockett-Torabi ◽  
J. C. Fantone
Keyword(s):  
Tyrosine Kinase ◽  
Reperfusion Injury ◽  
Protein Tyrosine Kinase ◽  
Kinase Inhibitor ◽  
Ischemia Reperfusion Injury ◽  
Leukocyte Adhesion ◽  
Ischemia Reperfusion ◽  
Second Messengers ◽  
Cross Linking ◽  
Calcium Signal

Neutrophils play an important role in myocardial ischemia-reperfusion injury. Neutrophil adhesion to the vascular endothelium is one of the important early mechanisms that lead to reperfusion injury. The leukocyte adhesion molecule, L-selectin, plays a major role in the initial interaction between neutrophils and endothelial cells. Intervention aimed at blocking selectins or their associated ligands can exert cardioprotective effects. The purpose of this study was to examine the role of L-selectin in the initiation of transmembrane signaling and regulation of canine neutrophil responses. Cross-linking of canine neutrophil L-selectin using anti-L-selectin antibody induced a rapid and transient increase in intracellular Ca2+ levels and superoxide anion generation that were dependent on the extent of L-selectin cross-linking. The responses were significantly inhibited by the protein tyrosine kinase inhibitor, genistein. The results demonstrate that ligation of canine neutrophil L-selectin is coupled to intracellular signal transduction pathways and the generation of second messengers, which may independently play important regulatory roles in modulating neutrophil-endothelial cell interactions.

scholarly journals Biophoton Imaging: A Nondestructive Method for Assaying R Gene Responses

2005 ◽  
Vol 18 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Mark Bennett ◽  
Monaz Mehta ◽  
Murray Grant
Keyword(s):  
Plant Disease Resistance ◽  
Photon Emission ◽  
Cytosolic Calcium ◽  
Defense Responses ◽  
Nondestructive Method ◽  
Genetic Dissection ◽  
Protein Signaling ◽  
Plant Defense Responses ◽  
Hypersensitive Cell Death ◽  
Repeat Class

Plant disease resistance (R) proteins of the nucleotide binding-leucine rich repeat class are responsible for pathogen recognition and activation of defense signaling networks leading to the hypersensitive response (HR). Genetically, R-protein signaling appears to be integrated through a limited set of common downstream components. However, the timing of development of visible HR is unique to individual R proteins. By utilizing the phenomena of ultraweak photon emission from leaves undergoing an incompatible interacttion, a powerful nondestructive and facile assay is described to compare timing of defense responses elicited by different R proteins. We demonstrate that ultraweak photon emission, or “biophoton generation,” is demonstrated to be associated with hypersensitive cell death. Biophoton emission requires an intact R signaling network and increases in cytosolic calcium and nitric oxide, but elevated reactive oxygen species are not necessary. Importantly, the assay is robust and applicable to a range of incompatible interactions in various plant species. The ability to assay R responses nondestructively in real time and a chosen genetic background makes this technique amenable to subtle genetic dissection of plant defense responses.

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