scholarly journals Molecular Crosstalk Between PAMP-Triggered Immunity and Photosynthesis

2012 ◽  
Vol 25 (8) ◽  
pp. 1083-1092 ◽  
Author(s):  
Vera Göhre ◽  
Alexandra M. E. Jones ◽  
Jan Sklenář ◽  
Silke Robatzek ◽  
Andreas P. M. Weber
Keyword(s):  
Defense Responses ◽  
Innate Immune ◽  
Energy Costs ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Fluorescence Measurements ◽  
Species Production ◽  
Molecular Patterns ◽  
Intrinsic Component ◽  
Molecular Crosstalk

The innate immune system allows plants to respond to potential pathogens in an appropriate manner while minimizing damage and energy costs. Photosynthesis provides a sustained energy supply and, therefore, has to be integrated into the defense against pathogens. Although changes in photosynthetic activity during infection have been described, a detailed and conclusive characterization is lacking. Here, we addressed whether activation of early defense responses by pathogen-associated molecular patterns (PAMPs) triggers changes in photosynthesis. Using proteomics and chlorophyll fluorescence measurements, we show that activation of defense by PAMPs leads to a rapid decrease in nonphotochemical quenching (NPQ). Conversely, NPQ also influences several responses of PAMP-triggered immunity. In a mutant impaired in NPQ, apoplastic reactive oxygen species production is enhanced and defense gene expression is differentially affected. Although induction of the early defense markers WRKY22 and WRKY29 is enhanced, induction of the late markers PR1 and PR5 is completely abolished. We propose that regulation of NPQ is an intrinsic component of the plant's defense program.

scholarly journals A small cysteine-rich phytotoxic protein of Phytophthora capsici functions as both plant defense elicitor and virulence factor

2021 ◽  
Author(s):  
Zi-Hui Zhang ◽  
Jinghao Jin ◽  
Gui-Lin Sheng ◽  
Yu-Ping Xing ◽  
Wang Liu ◽  
...  
Keyword(s):  
Plant Defense ◽  
Virulence Factor ◽  
Phytophthora Capsici ◽  
Ectopic Expression ◽  
Defense Responses ◽  
Phytophthora Species ◽  
Plant Interactions ◽  
Defense Gene Expression ◽  
Callose Deposition ◽  
Defense Gene

Small cysteine-rich (SCR) proteins including fungal avirulence proteins play important roles in the pathogen-plant interactions. SCR protein-encoding genes have been discovered in the genomes of Phytophthora pathogens, but their functions during the pathogenesis remain obscure. Here, we report the characterization of one Phytophthora capsici SCR protein, namely SCR82 with similarity to Phytophthora cactorum phytotoxic protein PcF. The scr82 gene has 10 allelic sequences in the P. capsici population. Homologues of SCR82 were not identified in fungi or other organisms but in Phytophthora relative species. Initially scr82 was weakly expressed during the mycelium, sporangium and zoospore stages, but quickly upregulated when the infection initiated. Both ectopic expression of SCR82 and recombinant yeast-expressed protein (rSCR82) caused cell death on tomato leaves. Upon treatment, rSCR82 induced plant defense responses including the induction of defense gene expression, reactive oxygen species burst and callose deposition. Knockout of scr82 in P. capsici by CRISPR/Cas9 severely impaired its virulence on host plants and reduced significantly its resistance againstoxidative stress. Inversely, its overexpression increased the pathogen’s virulence and tolerance to oxidative stress. Our results collectively demonstrate that SCR82 functions as both an important virulence factor and plant defense elicitor, which is conserved across Phytophthora species.

scholarly journals The Role of Peptide Signals Hidden in the Structure of Functional Proteins in Plant Immune Responses

2019 ◽  
Vol 20 (18) ◽  
pp. 4343 ◽  
Author(s):  
Irina Lyapina ◽  
Anna Filippova ◽  
Igor Fesenko
Keyword(s):  
Immune Responses ◽  
Defense Responses ◽  
Innate Immune ◽  
Functional Protein ◽  
Diverse Range ◽  
Peptide Signals ◽  
Plant Pathogen Interactions ◽  
Molecular Patterns ◽  
Damage Associated Molecular Patterns

Plants have evolved a sophisticated innate immune system to cope with a diverse range of phytopathogens and insect herbivores. Plasma-membrane-localized pattern recognition receptors (PRRs), such as receptor-like kinases (RLK), recognize special signals, pathogen- or damage-associated molecular patterns (PAMPs or DAMPs), and trigger immune responses. A growing body of evidence shows that many peptides hidden in both plant and pathogen functional protein sequences belong to the group of such immune signals. However, the origin, evolution, and release mechanisms of peptide sequences from functional and nonfunctional protein precursors, known as cryptic peptides, are largely unknown. Various special proteases, such as metacaspase or subtilisin-like proteases, are involved in the release of such peptides upon activation during defense responses. In this review, we discuss the roles of cryptic peptide sequences hidden in the structure of functional proteins in plant defense and plant-pathogen interactions.

scholarly journals Early Pep-13-induced immune responses are SERK3A/B-dependent in potato

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Linda Nietzschmann ◽  
Karin Gorzolka ◽  
Ulrike Smolka ◽  
Andreas Matern ◽  
Lennart Eschen-Lippold ◽  
...  
Keyword(s):  
Immune Responses ◽  
Defense Responses ◽  
Defense Gene Expression ◽  
Kinase Activation ◽  
Defense Gene ◽  
Potato Plants ◽  
Molecular Pattern ◽  
Hydroxycinnamic Acid Amides ◽  
Untargeted Metabolite Profiling ◽  
Blight Disease

AbstractPotato plants treated with the pathogen-associated molecular pattern Pep-13 mount salicylic acid- and jasmonic acid-dependent defense responses, leading to enhanced resistance against Phytophthora infestans, the causal agent of late blight disease. Recognition of Pep-13 is assumed to occur by binding to a yet unknown plasma membrane-localized receptor kinase. The potato genes annotated to encode the co-receptor BAK1, StSERK3A and StSERK3B, are activated in response to Pep-13 treatment. Transgenic RNAi-potato plants with reduced expression of both SERK3A and SERK3B were generated. In response to Pep-13 treatment, the formation of reactive oxygen species and MAP kinase activation, observed in wild type plants, is highly reduced in StSERK3A/B-RNAi plants, suggesting that StSERK3A/B are required for perception of Pep-13 in potato. In contrast, defense gene expression is induced by Pep-13 in both control and StSERK3A/B-depleted plants. Altered morphology of StSERK3A/B-RNAi plants correlates with major shifts in metabolism, as determined by untargeted metabolite profiling. Enhanced levels of hydroxycinnamic acid amides, typical phytoalexins of potato, in StSERK3A/B-RNAi plants are accompanied by significantly decreased levels of flavonoids and steroidal glycoalkaloids. Thus, altered metabolism in StSERK3A/B-RNAi plants correlates with the ability of StSERK3A/B-depleted plants to mount defense, despite highly decreased early immune responses.

scholarly journals The Immunity Regulator BAK1 Contributes to Resistance Against Diverse RNA Viruses

2013 ◽  
Vol 26 (11) ◽  
pp. 1271-1280 ◽  
Author(s):  
Camilla Julie Kørner ◽  
Dominik Klauser ◽  
Annette Niehl ◽  
Ana Domínguez-Ferreras ◽  
Delphine Chinchilla ◽  
...  
Keyword(s):  
Rna Viruses ◽  
Transcriptional Gene Silencing ◽  
Dependent Manner ◽  
Antiviral Defense ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Resistance Proteins ◽  
Post Transcriptional Gene Silencing ◽  
Effector Triggered Immunity ◽  
Molecular Patterns

The plant's innate immune system detects potential biotic threats through recognition of microbe-associated molecular patterns (MAMPs) or danger-associated molecular patterns (DAMPs) by pattern recognition receptors (PRR). A central regulator of pattern-triggered immunity (PTI) is the BRI1-associated kinase 1 (BAK1), which undergoes complex formation with PRR upon ligand binding. Although viral patterns inducing PTI are well known from animal systems, nothing similar has been reported for plants. Rather, antiviral defense in plants is thought to be mediated by post-transcriptional gene silencing of viral RNA or through effector-triggered immunity, i.e., recognition of virus-specific effectors by resistance proteins. Nevertheless, infection by compatible viruses can also lead to the induction of defense gene expression, indicating that plants may also recognize viruses through PTI. Here, we show that PTI, or at least the presence of the regulator BAK1, is important for antiviral defense of Arabidopsis plants. Arabidopsis bak1 mutants show increased susceptibility to three different RNA viruses during compatible interactions. Furthermore, crude viral extracts but not purified virions induce several PTI marker responses in a BAK1-dependent manner. Overall, we conclude that BAK1-dependent PTI contributes to antiviral resistance in plants.

scholarly journals Breaking Bad News: Dynamic Molecular Mechanisms of Wound Response in Plants

2020 ◽  
Vol 11 ◽  
Author(s):  
Isaac Vega-Muñoz ◽  
Dalia Duran-Flores ◽  
Álvaro Daniel Fernández-Fernández ◽  
Jefri Heyman ◽  
Andrés Ritter ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Wound Response ◽  
Surrounding Tissue ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Breaking Bad ◽  
Damage Recognition ◽  
Pathogen Colonization ◽  
Recognition And Response ◽  
Molecular Patterns

Recognition and repair of damaged tissue are an integral part of life. The failure of cells and tissues to appropriately respond to damage can lead to severe dysfunction and disease. Therefore, it is essential that we understand the molecular pathways of wound recognition and response. In this review, we aim to provide a broad overview of the molecular mechanisms underlying the fate of damaged cells and damage recognition in plants. Damaged cells release the so-called damage associated molecular patterns to warn the surrounding tissue. Local signaling through calcium (Ca2+), reactive oxygen species (ROS), and hormones, such as jasmonic acid, activates defense gene expression and local reinforcement of cell walls to seal off the wound and prevent evaporation and pathogen colonization. Depending on the severity of damage, Ca2+, ROS, and electrical signals can also spread throughout the plant to elicit a systemic defense response. Special emphasis is placed on the spatiotemporal dimension in order to obtain a mechanistic understanding of wound signaling in plants.

scholarly journals Phosphatidylcholines from Pieris brassicae eggs activate an immune response in Arabidopsis

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Elia Stahl ◽  
Théo Brillatz ◽  
Emerson Ferreira Queiroz ◽  
Laurence Marcourt ◽  
André Schmiesing ◽  
...  
Keyword(s):  
Pieris Brassicae ◽  
Fatty Acyl ◽  
Cell Surface Receptor ◽  
Ligand Specificity ◽  
Defense Gene Expression ◽  
Insect Eggs ◽  
Defense Gene ◽  
Surface Receptor ◽  
Acyl Chains ◽  
Molecular Patterns

Recognition of conserved microbial molecules activates immune responses in plants, a process termed pattern-triggered immunity (PTI). Similarly, insect eggs trigger defenses that impede egg development or attract predators, but information on the nature of egg-associated elicitors is scarce. We performed an unbiased bioactivity-guided fractionation of eggs of the butterfly Pieris brassicae. Nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry of active fractions led to the identification of phosphatidylcholines (PCs). PCs are released from insect eggs, and they induce salicylic acid and H2O2 accumulation, defense gene expression and cell death in Arabidopsis, all of which constitute a hallmark of PTI. Active PCs contain primarily C16 to C18-fatty acyl chains with various levels of desaturation, suggesting a relatively broad ligand specificity of cell-surface receptor(s). The finding of PCs as egg-associated molecular patterns (EAMPs) illustrates the acute ability of plants to detect conserved immunogenic patterns from their enemies, even from seemingly passive structures such as eggs.

scholarly journals Defense Gene Expression Associated with Biotrophic Phase of Mycosphaerella fijiensis M. Morelet Infection in Banana

Plant Disease ◽  
2016 ◽  
Vol 100 (6) ◽  
pp. 1170-1175 ◽  
Author(s):  
Hector A. Rodriguez ◽  
Esperanza Rodriguez-Arango ◽  
Juan G. Morales ◽  
Gert Kema ◽  
Rafael E. Arango
Keyword(s):  
Reference Genes ◽  
Ribosomal Subunit ◽  
Defense Responses ◽  
Mycosphaerella Fijiensis ◽  
Defense Gene Expression ◽  
Resistance Response ◽  
Defense Gene ◽  
Pathogenesis Related ◽  
Host Defense Response ◽  
Black Leaf Streak

Banana black leaf streak, caused by Mycosphaerella fijiensis M. Morelet, is a primary phytosanitary concern in export of this fruit around the world. To develop improved cultivars resistant to this disease, an understanding of host response to infection is necessary. In this study, we obtained expression data on 14,872 genes by microarray analysis in the resistant genotype Musa acuminata subsp. burmannicoides ‘Calcutta 4’ after inoculation with Mycosphaerella fijiensis. From these data, 16 genes were analyzed as potential reference genes and 12 genes were identified as potential early indicators of the onset of the host defense response. Subsequently, these genes were analyzed by quantitative reverse-transcription polymerase chain reaction in susceptible ‘Williams’ and resistant Calcutta 4. The 18S and 26S ribosomal subunit genes in both cultivars showed the best characteristics as reference genes. In all, 5 of the 12 defense genes expressed shortly after infection (peroxidase, pathogenesis-related [PR]-4, PR-10, phenylalanine ammonia-liase, and disease resistance response 1) showed overexpression in Calcutta 4 between 6 and 24 h after inoculation as opposed to Williams, which did not show overexpression after 144 h. Early induction of defense-related genes could be a key component of the resistance of the Calcutta 4 genotype against M. fijiensis. In addition, these five genes could be used as indicators of the activation of defense responses in the interaction between banana and M. fijiensis.

scholarly journals Transgenic expression of the dicotyledonous pattern recognition receptor EFR in rice leads to ligand-dependent activation of defense responses

2014 ◽  
Author(s):  
Benjamin Schwessinger ◽  
Ofir Bahar ◽  
Thomas Nicolas ◽  
Nicolas Holton ◽  
Vladimir Nekrasov ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pattern Recognition ◽  
Reactive Oxygen ◽  
Leaf Tissue ◽  
Defense Responses ◽  
Oxygen Production ◽  
Defense Gene Expression ◽  
Crop Species ◽  
Defense Gene ◽  
Enhanced Resistance

Plant plasma membrane localized pattern recognition receptors (PRRs) detect extracellular pathogen-associated molecules. PRRs such as Arabidopsis EFR and rice XA21 are taxonomically restricted and are absent from most plant genomes. Here we show that rice plants expressing EFR or the chimeric receptor EFR::XA21, containing the EFR ectodomain and the XA21 intracellular domain, sense both Escherichia coli- and Xanthomonas oryzae pv. oryzae (Xoo)-derived elf18 peptides at sub-nanomolar concentrations. Treatment of EFR and EFR::XA21 rice leaf tissue with elf18 leads to MAP kinase activation, reactive oxygen production and defense gene expression. Although expression of EFR does not lead to robust enhanced resistance to fully virulent Xoo isolates, it does lead to quantitatively enhanced resistance to weakly virulent Xoo isolates. EFR interacts with OsSERK2 and the XA21 binding protein 24 (XB24), two key components of the rice XA21-mediated immune response. Rice-EFR plants silenced for OsSERK2, or overexpressing rice XB24 are compromised in elf18-induced reactive oxygen production and defense gene expression indicating that these proteins are also important for EFR-mediated signaling in transgenic rice. Taken together, our results demonstrate the potential feasibility of enhancing disease resistance in rice and possibly other monocotyledonous crop species by expression of dicotyledonous PRRs. Our results also suggest that Arabidopsis EFR utilizes at least a subset of the known endogenous rice XA21 signaling components.

scholarly journals Cyclic Lipopeptides of Bacillus amyloliquefaciens subsp. plantarum Colonizing the Lettuce Rhizosphere Enhance Plant Defense Responses Toward the Bottom Rot Pathogen Rhizoctonia solani

2015 ◽  
Vol 28 (9) ◽  
pp. 984-995 ◽  
Author(s):  
Soumitra Paul Chowdhury ◽  
Jenny Uhl ◽  
Rita Grosch ◽  
Sylvia Alquéres ◽  
Sabrina Pittroff ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Plant Defense ◽  
Bacillus Amyloliquefaciens ◽  
Defense Responses ◽  
Disease Suppression ◽  
Plant Defense Responses ◽  
Defense Gene Expression ◽  
Defense Gene ◽  
Pathogen Challenge ◽  
Bottom Rot

The commercially available inoculant Bacillus amyloliquefaciens FZB42 is able to considerably reduce lettuce bottom rot caused by Rhizoctonia solani. To understand the interaction between FZB42 and R. solani in the rhizosphere of lettuce, we used an axenic system with lettuce bacterized with FZB42 and inoculated with R. solani. Confocal laser scanning microscopy showed that FZB42 could delay the initial establishment of R. solani on the plants. To show which secondary metabolites of FZB42 are produced under these in-situ conditions, we developed an ultra-high performance liquid chromatography coupled to time of flight mass spectrometry–based method and identified surfactin, fengycin, and bacillomycin D in the lettuce rhizosphere. We hypothesized that lipopeptides and polyketides play a role in enhancing the plant defense responses in addition to the direct antagonistic effect toward R. solani and used a quantitative real-time polymerase chain reaction–based assay for marker genes involved in defense signaling pathways in lettuce. A significant higher expression of PDF 1.2 observed in the bacterized plants in response to subsequent pathogen challenge showed that FZB42 could enhance the lettuce defense response toward the fungal pathogen. To identify if surfactin or other nonribosomally synthesized secondary metabolites could elicit the observed enhanced defense gene expression, we examined two mutants of FZB42 deficient in production of surfactin and the lipopetides and polyketides, by expression analysis and pot experiments. In the absence of surfactin and other nonribosomally synthesized secondary metabolites, there was no enhanced PDF 1.2–mediated response to the pathogen challenge. Pot experiment results showed that the mutants failed to reduce disease incidence in lettuce as compared with the FZB42 wild type, indicating, that surfactin as well as other nonribosomally synthesized secondary metabolites play a role in the actual disease suppression and on lettuce health. In conclusion, our study showed that nonribosomally synthesized secondary metabolites of FZB42 are actually produced in the lettuce rhizosphere and contribute to the disease suppression by mediating plant defense gene expression toward the pathogen R. solani.

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