scholarly journals Proteomic analysis of SUMO1-SUMOylome changes during defense elicitation in Arabidopsis

2020 ◽  
Author(s):  
Kishor D. Ingole ◽  
Shraddha K. Dahale ◽  
Saikat Bhattacharjee
Keyword(s):  
Pseudomonas Syringae ◽  
Defense Responses ◽  
Covalent Attachment ◽  
Wild Type ◽  
Rapid Adaptation ◽  
Post Translational Modification ◽  
Specific Receptors ◽  
Arabidopsis Mutant ◽  
Reversible Covalent

AbstractRapid adaptation of plants to developmental or physiological cues is facilitated by specific receptors that transduce the signals mostly via post-translational modification (PTM) cascades of downstream partners. Reversible covalent attachment of SMALL UBIQUITIN-LIKE MODIFIER (SUMO), a process termed as SUMOylation, influence growth, development and adaptation of plants to various stresses. Strong regulatory mechanisms maintain the steady-state SUMOylome and mutants with SUMOylation disturbances display mis-primed immunity often with growth consequences. Identity of the SUMO-substrates undergoing SUMOylation changes during defences however remain largely unknown. Here we exploit either the auto-immune property of an Arabidopsis mutant or defense responses induced in wild-type plants against Pseudomonas syringae pv tomato (PstDC3000) to enrich and identify SUMO1-substrates. Our results demonstrate massive enhancement of SUMO1-conjugates due to increased SUMOylation efficiencies during defense responses. Of the 261 proteins we identify, 29 have been previously implicated in immune-associated processes. Role of others expand to diverse cellular roles indicating massive readjustments the SUMOylome alterations may cause during induction of immunity. Overall, our study highlights the complexities of a plant immune network and identifies multiple SUMO-substrates that may orchestrate the signalling.

scholarly journals Uncoupling Salicylic Acid-Dependent Cell Death and Defense-Related Responses From Disease Resistance in the Arabidopsis Mutant acd5

Genetics ◽  
2000 ◽  
Vol 156 (1) ◽  
pp. 341-350
Author(s):  
Jean T Greenberg ◽  
F Paul Silverman ◽  
Hua Liang
Keyword(s):  
Cell Death ◽  
Salicylic Acid ◽  
Disease Resistance ◽  
Pseudomonas Syringae ◽  
Higher Plants ◽  
Ethylene Signaling ◽  
Symptom Development ◽  
Wild Type ◽  
Dependent Cell ◽  
Arabidopsis Mutant

Abstract Salicylic acid (SA) is required for resistance to many diseases in higher plants. SA-dependent cell death and defense-related responses have been correlated with disease resistance. The accelerated cell death 5 mutant of Arabidopsis provides additional genetic evidence that SA regulates cell death and defense-related responses. However, in acd5, these events are uncoupled from disease resistance. acd5 plants are more susceptible to Pseudomonas syringae early in development and show spontaneous SA accumulation, cell death, and defense-related markers later in development. In acd5 plants, cell death and defense-related responses are SA dependent but they do not confer disease resistance. Double mutants with acd5 and nonexpressor of PR1, in which SA signaling is partially blocked, show greatly attenuated cell death, indicating a role for NPR1 in controlling cell death. The hormone ethylene potentiates the effects of SA and is important for disease symptom development in Arabidopsis. Double mutants of acd5 and ethylene insensitive 2, in which ethylene signaling is blocked, show decreased cell death, supporting a role for ethylene in cell death control. We propose that acd5 plants mimic P. syringae-infected wild-type plants and that both SA and ethylene are normally involved in regulating cell death during some susceptible pathogen infections.

scholarly journals Mutations in the Bacillus thuringiensis Cry1Ca toxin demonstrate the role of domains II and III in specificity towards Spodoptera exigua larvae

2004 ◽  
Vol 384 (3) ◽  
pp. 507-513 ◽  
Author(s):  
Salvador HERRERO ◽  
Joel GONZÁLEZ-CABRERA ◽  
Juan FERRÉ ◽  
Petra L. BAKKER ◽  
Ruud A. de MAAGD
Keyword(s):  
Bacillus Thuringiensis ◽  
Spodoptera Exigua ◽  
Brush Border Membrane ◽  
Specific Activity ◽  
Membrane Vesicles ◽  
Wild Type ◽  
Oligomeric Form ◽  
Specific Receptors ◽  
Domain Iii

Several mutants of the Bacillus thuringiensis Cry1Ca toxin affected with regard to specific activity towards Spodoptera exigua were studied. Alanine was used to replace single residues in loops 2 and 3 of domain II (mutant pPB19) and to replace residues 541–544 in domain III (mutant pPB20). Additionally, a Cry1Ca mutant combining all mutations was constructed (mutant pPB21). Toxicity assays showed a marked decrease in toxicity against S. exigua for all mutants, while they retained their activity against Manduca sexta, confirming the importance of these residues in determining insect specificity. Parameters for binding to the specific receptors in BBMV (brush border membrane vesicles) of S. exigua were determined for all toxins. Compared with Cry1Ca, the affinity of mutant pPB19 was slightly affected (2-fold lower), whereas the affinity of the mutants with an altered domain III (pPB20 and pPB21) was approx. 8-fold lower. Activation of Cry1Ca protoxin by incubation with S. exigua or M. sexta BBMV revealed the transient formation of an oligomeric form of Cry1Ca. The presence of this oligomeric form was tested in the activation of the different Cry1Ca mutants, and we found that those mutated in domain II (pPB19 and pPB21) could not generate the oligomeric form when activated by S. exigua BBMV. In contrast, when oligomerization was tested using BBMV prepared from M. sexta, all of the Cry1Ca mutants showed the formation of a similar oligomeric form as did the wild-type toxin. Our results show how modification of insect specificity can be achieved by manipulation of different parts of the toxin structure involved in different steps of the mode of action of B. thuringiensis toxins.

scholarly journals Convergent Evolution of Effector Protease Recognition by Arabidopsis and Barley

2019 ◽  
Vol 32 (5) ◽  
pp. 550-565 ◽  
Author(s):  
Morgan E. Carter ◽  
Matthew Helm ◽  
Antony V. E. Chapman ◽  
Emily Wan ◽  
Ana Maria Restrepo Sierra ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Protease Activity ◽  
Phylogenetic Analyses ◽  
Defense Responses ◽  
Host Protein ◽  
Wheat Cultivars ◽  
Wild Type ◽  
Barley Cultivars ◽  
Resistance Protein ◽  
Effector Recognition

The Pseudomonas syringae cysteine protease AvrPphB activates the Arabidopsis resistance protein RPS5 by cleaving a second host protein, PBS1. AvrPphB induces defense responses in other plant species, but the genes and mechanisms mediating AvrPphB recognition in those species have not been defined. Here, we show that AvrPphB induces defense responses in diverse barley cultivars. We also show that barley contains two PBS1 orthologs, that their products are cleaved by AvrPphB, and that the barley AvrPphB response maps to a single locus containing a nucleotide-binding leucine-rich repeat (NLR) gene, which we termed AvrPphB Response 1 (Pbr1). Transient coexpression of PBR1 with wild-type AvrPphB but not with a protease inactive mutant triggered defense responses, indicating that PBR1 detects AvrPphB protease activity. Additionally, PBR1 coimmunoprecipitated with barley and Nicotiana benthamiana PBS1 proteins, suggesting mechanistic similarity to detection by RPS5. Lastly, we determined that wheat cultivars also recognize AvrPphB protease activity and contain two putative Pbr1 orthologs. Phylogenetic analyses showed, however, that Pbr1 is not orthologous to RPS5. Our results indicate that the ability to recognize AvrPphB evolved convergently and imply that selection to guard PBS1-like proteins occurs across species. Also, these results suggest that PBS1-based decoys may be used to engineer protease effector recognition–based resistance in barley and wheat.

scholarly journals Effects of Jasmonate on Ethylene Function during the Development of Tomato Stamens

Plants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 277 ◽  
Author(s):  
Ramona Schubert ◽  
Stephan Grunewald ◽  
Lea von Sivers ◽  
Bettina Hause
Keyword(s):  
Water Content ◽  
Minor Role ◽  
Wild Type ◽  
Stamen Development ◽  
Hormone Levels ◽  
Pollen Release ◽  
Arabidopsis Mutant ◽  
Ethylene Function ◽  
Pollen Vitality

The phenotype of the tomato mutant jasmonate-insensitive1-1 (jai1-1) mutated in the JA-Ile co-receptor COI1 demonstrates JA function in flower development, since it is female-sterile. In addition, jai1-1 exhibits a premature anther dehydration and pollen release, being in contrast to a delayed anther dehiscence in the JA-insensitive Arabidopsis mutant coi1-1. The double mutant jai1-1 Never ripe (jai1-1 Nr), which is in addition insensitive to ethylene (ET), showed a rescue of the jai1-1 phenotype regarding pollen release. This suggests that JA inhibits a premature rise in ET to prevent premature stamen desiccation. To elucidate the interplay of JA and ET in more detail, stamen development in jai1-1 Nr was compared to wild type, jai1-1 and Nr regarding water content, pollen vitality, hormone levels, and accumulation of phenylpropanoids and transcripts encoding known JA- and ET-regulated genes. For the latter, RT-qPCR based on nanofluidic arrays was employed. The data showed that additional prominent phenotypic features of jai1-1, such as diminished water content and pollen vitality, and accumulation of phenylpropanoids were at least partially rescued by the ET-insensitivity. Hormone levels and accumulation of transcripts were not affected. The data revealed that strictly JA-regulated processes cannot be rescued by ET-insensitivity, thereby emphasizing a rather minor role of ET in JA-regulated stamen development.

scholarly journals Involvement of the Small GTPase Rac in the Defense Responses of Tobacco to Pathogens

2005 ◽  
Vol 18 (2) ◽  
pp. 116-124 ◽  
Author(s):  
Wolfgang Moeder ◽  
Keiko Yoshioka ◽  
Daniel F. Klessig
Keyword(s):  
Nadph Oxidase ◽  
Pseudomonas Syringae ◽  
Systemic Acquired Resistance ◽  
Defense Responses ◽  
Small Gtpase ◽  
Dominant Negative ◽  
Dominant Negative Effect ◽  
Helicase Domain ◽  
Wild Type ◽  
Antioxidant Genes

During the hypersensitive response (HR), plants accumulate reactive oxygen species (ROS) that are likely generated at least in part by an NADPH oxidase similar to that found in mammalian neutrophils. An essential regulator of mammalian NADPH oxidase is the small GTP-binding protein Rac. To investigate whether Rac also regulates the pathogen-induced oxidative burst in plants, a dominant negative form of the rice OsRac1 gene was overexpressed in tobacco carrying the N resistance gene. Following infection with Tobacco mosaic virus (TMV), DN-OsRac1 plants developed smaller lesions than wild-type plants, accumulated lower levels of lipid peroxidation products, and failed to activate expression of antioxidant genes. These results, combined with the demonstration that superoxide and hydrogen peroxide levels were reduced in DN-OsRac1 tobacco developing a synchronous HR triggered by transient expression of the TMV p50 helicase domain or the Pto and AvrPto proteins, suggest that ROS production is impaired. The dominant negative effect of DN-OsRac1 could be rescued by transiently overexpressing the wild-type OsRac1 protein. TMV-induced salicylic acid accumulation also was compromised in DN-OsRac1 tobacco. Interestingly, while systemic acquired resistance to TMV was not impaired, nonhost resistance to Pseudomonas syringae pv. maculicola ES4326 was suppressed. Thus, the effect DN-OsRac1 expression exerts on the resistance signaling pathway appears to vary depending on the identity of the inoculated pathogen.

scholarly journals Role of Jasmonic Acid Pathway in Tomato Plant-Pseudomonas syringae Interaction

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 136 ◽  
Author(s):  
Loredana Scalschi ◽  
Eugenio Llorens ◽  
Pilar García-Agustín ◽  
Begonya Vicedo
Keyword(s):  
Gene Expression ◽  
Salicylic Acid ◽  
Jasmonic Acid ◽  
Pseudomonas Syringae ◽  
Tomato Plant ◽  
Wild Type ◽  
Tomato Plants ◽  
Bacterial Pathogenicity ◽  
Acid Pathway

The jasmonic acid pathway has been considered as the backbone of the response against necrotrophic pathogens. However, a hemi-biotrophic pathogen, such as Pseudomonas syringae, has taken advantage of the crosstalk between the different plant hormones in order to manipulate the responses for its own interest. Despite that, the way in which Pseudomonas syringae releases coronatine to activate jasmonic acid-derived responses and block the activation of salicylic acid-mediated responses is widely known. However, the implication of the jasmonic intermediates in the plant-Pseudomonas interaction is not studied yet. In this work, we analyzed the response of both, plant and bacteria using SiOPR3 tomato plants. Interestingly, SiOPR3 plants are more resistant to infection with Pseudomonas. The gene expression of bacteria showed that, in SiOPR3 plants, the activation of pathogenicity is repressed in comparison to wild type plants, suggesting that the jasmonic acid pathway might play a role in the pathogenicity of the bacteria. Moreover, treatments with JA restore the susceptibility as well as activate the expression of bacterial pathogenicity genes. The observed results suggest that a complete jasmonic acid pathway is necessary for the susceptibility of tomato plants to Pseudomonas syringae.

scholarly journals Pseudomonas syringae Evades Host Immunity by Degrading Flagellin Monomers with Alkaline Protease AprA

2014 ◽  
Vol 27 (7) ◽  
pp. 603-610 ◽  
Author(s):  
Michiel J. C. Pel ◽  
Anja J. H. van Dijken ◽  
Bart W. Bardoel ◽  
Michael F. Seidl ◽  
Sjoerd van der Ent ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Alkaline Protease ◽  
Bacterial Species ◽  
Gene Activation ◽  
Ectopic Expression ◽  
Host Immunity ◽  
Wild Type ◽  
Knockout Mutant ◽  
Inhibitory Peptide

Bacterial flagellin molecules are strong inducers of innate immune responses in both mammals and plants. The opportunistic pathogen Pseudomonas aeruginosa secretes an alkaline protease called AprA that degrades flagellin monomers. Here, we show that AprA is widespread among a wide variety of bacterial species. In addition, we investigated the role of AprA in virulence of the bacterial plant pathogen P. syringae pv. tomato DC3000. The AprA-deficient DC3000 ΔaprA knockout mutant was significantly less virulent on both tomato and Arabidopsis thaliana. Moreover, infiltration of A. thaliana Col-0 leaves with DC3000 ΔaprA evoked a significantly higher level of expression of the defense-related genes FRK1 and PR-1 than did wild-type DC3000. In the flagellin receptor mutant fls2, pathogen virulence and defense-related gene activation did not differ between DC3000 and DC3000 ΔaprA. Together, these results suggest that AprA of DC3000 is important for evasion of recognition by the FLS2 receptor, allowing wild-type DC3000 to be more virulent on its host plant than AprA-deficient DC3000 ΔaprA. To provide further evidence for the role of DC3000 AprA in host immune evasion, we overexpressed the AprA inhibitory peptide AprI of DC3000 in A. thaliana to counteract the immune evasive capacity of DC3000 AprA. Ectopic expression of aprI in A. thaliana resulted in an enhanced level of resistance against wild-type DC3000, while the already elevated level of resistance against DC3000 ΔaprA remained unchanged. Together, these results indicate that evasion of host immunity by the alkaline protease AprA is important for full virulence of strain DC3000 and likely acts by preventing flagellin monomers from being recognized by its cognate immune receptor.

scholarly journals The Role of Ethylene Production in Virulence of Pseudomonas syringae pvs. glycinea and phaseolicola

2001 ◽  
Vol 91 (5) ◽  
pp. 511-518 ◽  
Author(s):  
Helge Weingart ◽  
Henriette Ullrich ◽  
Klaus Geider ◽  
Beate Völksch
Keyword(s):  
Pseudomonas Syringae ◽  
Ethylene Production ◽  
Type Strain ◽  
Wild Type Strain ◽  
Wild Type ◽  
In Planta ◽  
Population Sizes ◽  
Soybean Plants ◽  
Type Strains

The importance of ethylene production for virulence of Pseudomonas syringae pvs. glycinea and phaseolicola was assayed by comparing bacterial multiplication and symptom development in bean and soybean plants inoculated with ethylene-negative (efe) mutants and wild-type strains. The efe mutants of Pseudomonas syringae pv. glycinea were significantly reduced in their ability to grow in planta. However, the degree of reduction was strain-dependent. Population sizes of efe mutant 16/83-E1 that did not produce the phototoxin coronatine were 10- and 15-fold lower than those of the wild-type strain on soybean and on bean, and 16/83-E1 produced very weak symptoms compared with the wild-type strain. The coronatine-producing efe mutant 7a/90-E1 reached fourfold and twofold lower population sizes compared with the wild-type strain on soybean and bean, respectively, and caused disease symptoms typical of the wild-type strain. Experiments with ethylene-insensitive soybeans confirmed these results. The virulence of the wild-type strains was reduced to the same extent in ethylene-insensitive soybean plants as the virulence of the efe mutants in ethylene-susceptible soybeans. In contrast, the virulence of Pseudomonas syringae pv. phaseolicola was not affected by disruption of the efe gene.

scholarly journals Contrasting functions of Arabidopsis SUMO1/2 isoforms with SUMO3 intersect to modulate innate immunity and global SUMOylome responses

2020 ◽  
Author(s):  
Kishor Dnyaneshwar Ingole ◽  
Mritunjay Kasera ◽  
Harrold A. van den Burg ◽  
Saikat Bhattacharjee
Keyword(s):  
Arabidopsis Thaliana ◽  
Steady State ◽  
Heat Shock ◽  
Pseudomonas Syringae ◽  
Bacterial Pathogen ◽  
Defense Responses ◽  
Vital Role ◽  
Covalent Attachment ◽  
Developmental Defects ◽  
Small Proteins

AbstractReversible covalent attachment of SMALL UBIQUITIN-LIKE MODIFIERS (SUMOs) on target proteins regulate diverse cellular process across all eukaryotes. In Arabidopsis thaliana, most mutants with perturbed global SUMOylome display severe impairments in growth and adaptations to physiological stresses. Since SUMOs self-regulate activities of SUMOylation-associated proteins, existence of multiple isoforms introduces possibilities of their functional intersections which remain unexplored especially in plant systems. Using well-established defense responses elicited against virulent and avirulent Pseudomonas syringae pv. tomato strains, we investigated crosstalks in individual and combinatorial Arabidopsis sum mutants. Here we report that while SUM1 and SUM2 additively, but not equivalently suppress basal and TNL-specific immunity via down-regulation of salicylic acid (SA)-dependent responses, SUM3 promotes these defenses genetically downstream of SA. Remarkably, the expression of SUM3 is transcriptionally suppressed by SUMO1 or SUMO2. The loss of SUM3 not only lowers basal or post-bacterial challenge responsive enhancements of SUMO1/2-congugates but also reduces upregulation dynamics of defensive proteins and SUMOylation-associated transcripts. Combining a sum3 mutation partially attenuates heightened immunity of sum1 or sum2 mutants suggesting intricate functional impingements among these isoforms in optimizing immune amplitudes. Similar SUM1-SUM3 intersections also affect global SUMOylome responses to heat-shock affecting most notably the induction of selective heat-shock transcription factors. Overall, our investigations reveal novel insights into auto-regulatory mechanisms among SUMO isoforms in host SUMOylome maintenance and adjustments to environmental challenges.Author SummaryIn plants, similar to animals, protein functions are regulated at multiple levels. One prevalent mode is to allow covalent linkage of small proteins to specific amino acids on targets thereby affecting its fate and function. One such kind of modification named as SUMOylation involves attachment of SUMO proteins. A plant maintains strict control over its pool of SUMOylated proteins (termed SUMOylome) which upon biotic or abiotic stresses are altered to facilitate appropriate responses, returning back to steady-state when the threat subsides. In mutants of the model plant Arabidopsis thaliana having disturbed steady-state SUMOylome, growth and developmental defects ensue. These mutants are auto-immune showing more resistance to infection by the bacterial pathogen Pseudomonas syringae. However, Arabidopsis SUMO-family are comprised of multiple members raising the question about their specificity or functional crosstalks. We discovered that two SUMO members function in coordination to suppress immunity including the repression of a third member which supports defenses. The expression of this third member during pathogen attack or heat-shock influences the responsive changes in the host SUMOylome likely suggesting SUMOs themselves play vital role in these adaptations. Overall, our work highlights novel intersections of SUMO members in mounting stress-specific responses.

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