scholarly journals Comprehensive Identification of PTI Suppressors in Type III Effector Repertoire Reveals that Ralstonia solanacearum Activates Jasmonate Signaling at Two Different Steps

2019 ◽  
Vol 20 (23) ◽  
pp. 5992 ◽  
Author(s):  
Masahito Nakano ◽  
Takafumi Mukaihara
Keyword(s):  
Pseudomonas Syringae ◽  
Cysteine Protease ◽  
Ralstonia Solanacearum ◽  
Acid Synthesis ◽  
Defense Responses ◽  
Dependent Manner ◽  
Jaz Proteins ◽  
Ros Burst ◽  
Ja Signaling ◽  
Activity Dependent

Ralstonia solanacearum is the causative agent of bacterial wilt in many plants. To identify R. solanacearum effectors that suppress pattern-triggered immunity (PTI) in plants, we transiently expressed R. solanacearum RS1000 effectors in Nicotiana benthamiana leaves and evaluated their ability to suppress the production of reactive oxygen species (ROS) triggered by flg22. Out of the 61 effectors tested, 11 strongly and five moderately suppressed the flg22-triggered ROS burst. Among them, RipE1 shared homology with the Pseudomonas syringae cysteine protease effector HopX1. By yeast two-hybrid screening, we identified jasmonate-ZIM-domain (JAZ) proteins, which are transcriptional repressors of the jasmonic acid (JA) signaling pathway in plants, as RipE1 interactors. RipE1 promoted the degradation of JAZ repressors and induced the expressions of JA-responsive genes in a cysteine–protease-activity-dependent manner. Simultaneously, RipE1, similarly to the previously identified JA-producing effector RipAL, decreased the expression level of the salicylic acid synthesis gene that is required for the defense responses against R. solanacearum. The undecuple mutant that lacks 11 effectors with a strong PTI suppression activity showed reduced growth of R. solanacearum in Nicotiana plants. These results indicate that R. solanacearum subverts plant PTI responses using multiple effectors and manipulates JA signaling at two different steps to promote infection.

scholarly journals Epicutaneous Administration of Papain Induces IgE and IgG Responses in a Cysteine Protease Activity-Dependent Manner

2014 ◽  
Vol 63 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Hideo Iida ◽  
Toshiro Takai ◽  
Yusuke Hirasawa ◽  
Seiji Kamijo ◽  
Sakiko Shimura ◽  
...  
Keyword(s):  
Cysteine Protease ◽  
Protease Activity ◽  
Dependent Manner ◽  
Cysteine Protease Activity ◽  
Activity Dependent

scholarly journals Novel molecular components involved in callose-mediated Arabidopsis defense against Salmonella enterica and Escherichia coli O157:H7

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Paula Rodrigues Oblessuc ◽  
Cleverson Carlos Matiolli ◽  
Maeli Melotto
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Syringae ◽  
Salmonella Enterica ◽  
Plant Pathogens ◽  
Dependent Manner ◽  
Callose Deposition ◽  
E Coli ◽  
Genetic Components ◽  
Ros Burst ◽  
Sa Signaling

Abstract Background Food contamination with Salmonella enterica and enterohemorrhagic Escherichia coli is among the leading causes of foodborne illnesses worldwide and crop plants are associated with > 50% of the disease outbreaks. However, the mechanisms underlying the interaction of these human pathogens with plants remain elusive. In this study, we have explored plant resistance mechanisms against these enterobacteria and the plant pathogen Pseudomonas syringae pv. tomato (Pst) DC3118, as an opportunity to improve food safety. Results We found that S. enterica serovar Typhimurium (STm) transcriptionally modulates stress responses in Arabidopsis leaves, including induction of two hallmark processes of plant defense: ROS burst and cell wall modifications. Analyses of plants with a mutation in the potentially STm-induced gene EXO70H4 revealed that its encoded protein is required for stomatal defense against STm and E. coli O157:H7, but not against Pst DC3118. In the apoplast however, EXO70H4 is required for defense against STm and Pst DC3118, but not against E. coli O157:H7. Moreover, EXO70H4 is required for callose deposition, but had no function in ROS burst, triggered by all three bacteria. The salicylic acid (SA) signaling and biosynthesis proteins NPR1 and ICS1, respectively, were involved in stomatal and apoplastic defense, as well as callose deposition, against human and plant pathogens. Conclusions The results show that EXO70H4 is involved in stomatal and apoplastic defenses in Arabidopsis and suggest that EXO70H4-mediated defense play a distinct role in guard cells and leaf mesophyll cells in a bacteria-dependent manner. Nonetheless, EXO70H4 contributes to callose deposition in response to both human and plant pathogens. NPR1 and ICS1, two proteins involved in the SA signaling pathway, are important to inhibit leaf internalization and apoplastic persistence of enterobacteria and proliferation of phytopathogens. These findings highlight the existence of unique and shared plant genetic components to fight off diverse bacterial pathogens providing specific targets for the prevention of foodborne diseases.

scholarly journals The Plant Growth–Promoting Rhizobacterium Bacillus cereus AR156 Induces Systemic Resistance in Arabidopsis thaliana by Simultaneously Activating Salicylate- and Jasmonate/Ethylene-Dependent Signaling Pathways

2011 ◽  
Vol 24 (5) ◽  
pp. 533-542 ◽  
Author(s):  
Dong-Dong Niu ◽  
Hong-Xia Liu ◽  
Chun-Hao Jiang ◽  
Yun-Peng Wang ◽  
Qing-Ya Wang ◽  
...  
Keyword(s):  
Plant Growth ◽  
Bacillus Cereus ◽  
Signaling Pathways ◽  
Pseudomonas Syringae ◽  
Defense Responses ◽  
Systemic Resistance ◽  
Dependent Manner ◽  
Challenge Inoculation ◽  
Plant Growth Promoting ◽  
Growth Promoting

Bacillus cereus AR156 is a plant growth–promoting rhizobacterium that induces resistance against a broad spectrum of pathogens including Pseudomonas syringae pv. tomato DC3000. This study analyzed AR156-induced systemic resistance (ISR) to DC3000 in Arabidopsis ecotype Col-0 plants. Compared with mock-treated plants, AR156-treated ones showed an increase in biomass and reductions in disease severity and pathogen density in the leaves. The defense-related genes PR1, PR2, PR5, and PDF1.2 were concurrently expressed in the leaves of AR156-treated plants, suggesting simultaneous activation of the salicylic acid (SA)- and the jasmonic acid (JA)- and ethylene (ET)-dependent signaling pathways by AR156. The above gene expression was faster and stronger in plants treated with AR156 and inoculated with DC3000 than that in plants only inoculated with DC3000. Moreover, the cellular defense responses hydrogen peroxide accumulation and callose deposition were induced upon challenge inoculation in the leaves of Col-0 plants primed by AR156. Also, pretreatment with AR156 led to a higher level of induced protection against DC3000 in Col-0 than that in the transgenic NahG, the mutant jar1 or etr1, but the protection was absent in the mutant npr1. Therefore, AR156 triggers ISR in Arabidopsis by simultaneously activating the SA- and JA/ET-signaling pathways in an NPR1-dependent manner that leads to an additive effect on the level of induced protection.

scholarly journals Hexanoic Acid-Induced Resistance Against Botrytis cinerea in Tomato Plants

2009 ◽  
Vol 22 (11) ◽  
pp. 1455-1465 ◽  
Author(s):  
Begonya Vicedo ◽  
Víctor Flors ◽  
María de la O Leyva ◽  
Ivan Finiti ◽  
Zhana Kravchuk ◽  
...  
Keyword(s):  
Botrytis Cinerea ◽  
Induced Resistance ◽  
Pseudomonas Syringae ◽  
Hexanoic Acid ◽  
Dependent Manner ◽  
Deficient Mutant ◽  
Callose Deposition ◽  
Tomato Plants ◽  
In The Wild ◽  
Ja Signaling

We have demonstrated that root treatment with hexanoic acid protects tomato plants against Botrytis cinerea. Hexanoic acid-induced resistance (Hx-IR) was blocked in the jasmonic acid (JA)-insensitive mutant jai1 (a coi1 homolog) and in the abscisic acid (ABA)-deficient mutant flacca (flc). Upon infection, the LoxD gene as well as the oxylipin 12-oxo-phytodienoic acid and the bioactive molecule JA-Ile were clearly induced in treated plants. However, the basal ABA levels were not altered. Hexanoic acid primed callose deposition against B. cinerea in a cultivar-dependent manner. Treated plants from Ailsa Craig, Moneymaker, and Rheinlands Ruhm showed increased callose deposition but not from Castlemart. Hexanoic acid did not prime callose accumulation in flc plants upon B. cinerea infection; therefore, ABA could act as a positive regulator of Hx-IR by enhancing callose deposition. Furthermore, although hexanoic acid protected the JA-deficient mutant defensless1 (def1), the priming for callose was higher than in the wild type. This suggests a link between JA and callose deposition in tomato. Hence, the obtained results support the idea that callose, oxylipins, and the JA-signaling pathway are involved in Hx-IR against B. cinerea. Moreover our data support the relevance of JA-signaling for basal defense against this necrotroph in tomato. Hexanoic acid also protected against Pseudomonas syringae, indicating a broad-spectrum effect for this new inducer.

Functional characterization of the Arabidopsis disease resistance gene RPS4

2005 ◽  
Author(s):  
◽  
Xue-Cheng Zhang
Keyword(s):  
Disease Resistance ◽  
Alternative Splicing ◽  
Protein Stability ◽  
Resistance Gene ◽  
Pseudomonas Syringae ◽  
Defense Responses ◽  
Alternative Transcript ◽  
Disease Resistance Gene ◽  
Dependent Manner ◽  
Multiple Transcripts

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The Arabidopsis disease resistance gene RPS4 activates defense responses to the bacterial pathogen Pseudomonas syringae pv. tomato strain DC3000 expressing avrRps4 in a gene-for-gene specific manner. Like other plant TIRNBS-LRR resistance genes, RPS4 produces multiple transcripts via alternative splicing. Alternative RPS4 transcripts are predominantly generated by intron retention. First, the biological significance of these alternative transcripts in disease resistance was analyzed. It was shown that alternative RPS4 transcripts are required for complete function and that RPS4-mediated resistance requires the combined presence of multiple transcripts encoding both full-length and truncated open reading frames. Interestingly, the dominant alternative transcript is the only alternative transcript whose abundance relative to the regular transcript undergoes dramatic and dynamic changes during the resistance response. Furthermore, RPS4 expression is induced by AvrRps4 and an unrelated effector, HopPsyA, in an EDS1-dependent manner. These data suggest that rapid gene induction and changes in transcript ratios might be under coordinated regulation that are important to fine-tune RPS4-mediated resistance. Our previous data showed that removal of one intron abolished RPS4 function. However, no significant changes of transcript ratios in intron-deficient transgenic rps4-1 plants were observed compared to rps4-1 expressing a wild type genomic transgene, suggesting that the artificial removal of one intron has no effect on the splicing frequency of other introns. In consistent with our previous data, analyses on secondary RNA structures suggest that alternative RPS4 transcripts function at protein level. Of the three expected truncated RPS4 proteins, only one was detected and stable in vivo, indicating that RPS4 protein stability or activity is regulated. In summary, RPS4 function is regulated at multiple levels including gene expression, alternative splicing and protein stability or activity.

scholarly journals Planthopper-Secreted Salivary Disulfide Isomerase Activates Immune Responses in Plants

2021 ◽  
Vol 11 ◽  
Author(s):  
Jianmei Fu ◽  
Yu Shi ◽  
Lu Wang ◽  
Hao Zhang ◽  
Jing Li ◽  
...  
Keyword(s):  
Cell Death ◽  
Molecular Mechanisms ◽  
Brown Planthopper ◽  
Defense Responses ◽  
Salivary Proteins ◽  
Plant Host ◽  
Callose Deposition ◽  
Disulfide Isomerase ◽  
Ros Burst ◽  
Ja Signaling

The small brown planthopper (Laodelphax striatellus; SBPH) is a piercing-sucking insect that secretes salivary proteins into its plant host during feeding. However, the mechanisms by which these salivary proteins regulate plant defense responses remain poorly understood. Here, we identified the disulfide isomerase (LsPDI1) in the SBPH salivary proteome. LsPDI1 was highly expressed in the SBPH salivary glands and secreted into rice plants during feeding. Transient in planta LsPDI1 expression in the absence of signal peptide induced reactive oxygen species (ROS) burst, cell death, callose deposition, and jasmonic acid (JA) signaling pathway. Deletion mutant analysis revealed that either the a-b-b’ or the b-b’-a’ domains in LsPDI1 are required to induce cell death in plants. LsPDI1 and its orthologs were highly conserved among various planthopper species and strongly induced ROS burst and cell death in plants. Transient in Nicotiana benthamiana LsPDI1 expression impaired the performance of Spodoptera frugiperda and Myzus persicae on host plants. Hence, LsPDI1 is an important salivary elicitor that enhances plant resistance to insects by inducing the calcium, ROS, and JA signaling pathways. The findings of this study provide novel insights into the molecular mechanisms underlying plant-insect interactions.

scholarly journals SmbHLH37 functions antagonistically with SmMYC2 in regulating jasmonate-mediated biosynthesis of phenolic acids in Salvia miltiorrhiza

2018 ◽  
Author(s):  
Tang-Zhi Du ◽  
Jun-Feng Niu ◽  
Jiao Su ◽  
Sha-Sha Li ◽  
Xiao-Rong Guo ◽  
...  
Keyword(s):  
Target Genes ◽  
Salvia Miltiorrhiza ◽  
Functional Characterization ◽  
Constitutive Expression ◽  
Defense Responses ◽  
Bhlh Transcription Factor ◽  
Bhlh Gene ◽  
Helix Loop Helix ◽  
Jaz Proteins ◽  
Ja Signaling

AbstractJasmonates (JAs) are integral to various defense responses and induce biosynthesis of many secondary metabolites. MYC2, a basic helix-loop-helix (bHLH) transcription factor (TF), acts as a transcriptional activator of JA signaling. MYC2 is repressed by the JASMONATE ZIM-domain (JAZ) proteins in the absence of JA, but de-repressed by the protein complex SCFCOI1 on perception of JA. We previously reported that overexpression of SmMYC2 promotes the production of salvianolic acid B (Sal B) in Salvia miltiorrhiza. However, the responsible molecular mechanism is unclear. Here, we showed that SmMYC2 binds to and activates the promoters of its target genes SmTAT1, SmPAL1, and SmCYP98A14 to activate Sal B accumulations. SmbHLH37, a novel bHLH gene significantly up-regulated by constitutive expression of SmMYC2, was isolated from S. miltiorrhiza for detailed functional characterization. SmbHLH37 forms a homodimer and interacts with SmJAZ3/8. Overexpression of SmbHLH37 substantially decreased yields of Sal B. SmbHLH37 binds to the promoters of its target genes SmTAT1 and SmPAL1 and blocks their expression to suppress the pathway for Sal B biosynthesis. These results indicate that SmbHLH37 negatively regulates JA signaling and functions antagonistically with SmMYC2 in regulating Sal B biosynthesis in S. miltiorrhiza.

scholarly journals Key Genes in the Jaz Signaling Pathway Are Up-regulated Faster and More Abundantly in Caterpillar-resistant Maize

2021 ◽  
Author(s):  
Yang Han ◽  
DAWN LUTHE
Keyword(s):  
Fall Armyworm ◽  
Defense Responses ◽  
Plant Responses ◽  
Limited Information ◽  
Mechanical Wounding ◽  
Transcript Levels ◽  
Jaz Proteins ◽  
Regulation Function ◽  
Key Genes ◽  
Ja Signaling

Abstract Jasmonic acid (JA) and its derivatives, collectively known as jasmonates (JAs), are important signaling hormones for plant responses against chewing herbivores. In JA signaling networks, jasmonate ZIM-domain (JAZ) proteins are transcriptional repressors that regulate JA-modulated downstream herbivore defenses. JAZ repressors are widely presented in land plants, however, there is only limited information about the regulation/function of JAZ proteins in maize. In this study, we performed a comprehensive expression analysis of ZmJAZ genes with other selected genes in the jasmonate pathway in response to feeding by fall armyworm (Spodoptera frugiperda, FAW), mechanical wounding, and exogenous hormone treatments in two maize genotypes differing in FAW resistance. Results showed that transcript levels of JAZ genes and several key genes in JA-signaling and biosynthesis pathways were rapidly and abundantly expressed in both genotypes in response to these various treatments. However, there were key differences between the two genotypes in the expression of ZmJAZ1 and ZmCOI1a, these two genes were expressed significantly rapidly and abundantly in the resistant line which was tightly regulated by endogenous JA level upon feeding. For instance, transcript levels of ZmJAZ1 increase dramatically within 30 min of FAW-fed Mp708 but not Tx601, correlating with the JA accumulation. The results also demonstrated that wounding or JA treatment alone was not as effective as FAW feeding; this suggests that insect-derived factors are required for optimal defense responses.

scholarly journals Ectomycorrhizal fungi induce systemic resistance against insects on a non-mycorrhizal plant in a CERK1-dependent manner

2019 ◽  
Author(s):  
Kishore Vishwanathan ◽  
Krzysztof Zienkiewicz ◽  
Yang Liu ◽  
Dennis Janz ◽  
Ivo Feussner ◽  
...  
Keyword(s):  
Pseudomonas Syringae ◽  
Trichoplusia Ni ◽  
Bacterial Pathogen ◽  
Systemic Resistance ◽  
Dependent Manner ◽  
Induce Systemic Resistance ◽  
Mycorrhizal Plant ◽  
Plant Host ◽  
Mediated Effects ◽  
Ja Signaling

ABSTRACTBelow-ground microbes can induce systemic resistance (ISR) against foliar pests and pathogens on diverse plant hosts. The prevalence of ISR among plant-microbe-pest systems raises the question of host specificity in microbial induction of ISR. To test whether ISR is limited by plant host range, we tested the ISR-inducing ectomycorrhizal (ECM) fungus Laccaria bicolor on the non-mycorrhizal plant Arabidopsis. We found that root inoculation with L. bicolor triggered ISR against the insect herbivore Trichoplusia ni and induced systemic susceptibility (ISS) against the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 (Pto). We found that L. bicolor-triggered ISR against T. ni was dependent on jasmonic acid (JA) signaling and salicylic acid (SA) biosynthesis and signaling. We found that heat killed L. bicolor and chitin are sufficient to trigger ISR against T. ni and ISS against Pto and that the chitin receptor CERK1 is necessary for L. bicolor-mediated effects on systemic immunity. Collectively our findings suggest that some ISR responses might not require intimate co-evolution of host and microbe, but rather might be the result of root perception of conserved microbial signals.

scholarly journals Ethylene and Jasmonic Acid Signaling Affect the NPR1-Independent Expression of Defense Genes Without Impacting Resistance to Pseudomonas syringae and Peronospora parasitica in the Arabidopsis ssi1 Mutant

2003 ◽  
Vol 16 (7) ◽  
pp. 588-599 ◽  
Author(s):  
Ashis Nandi ◽  
Pradeep Kachroo ◽  
Hirotada Fukushige ◽  
David F. Hildebrand ◽  
Daniel F. Klessig ◽  
...  
Keyword(s):  
Jasmonic Acid ◽  
Plant Defense ◽  
Pseudomonas Syringae ◽  
Defense Mechanism ◽  
Constitutive Expression ◽  
Defense Responses ◽  
Peronospora Parasitica ◽  
Defense Genes ◽  
Pr Genes ◽  
Ja Signaling

Salicylic acid (SA), ethylene, and jasmonic acid (JA) are important signaling molecules in plant defense to biotic stress. An intricate signaling network involving SA, ethylene, and JA fine tunes plant defense responses. SA-dependent defense responses in Arabidopsis thaliana are mediated through NPR1-dependent and -independent mechanisms. We have previously shown that activation of an NPR1-independent defense mechanism confers enhanced disease resistance and constitutive expression of the pathogenesis-related (PR) genes in the Arabidopsis ssi1 mutant. In addition, the ssi1 mutant constitutively expresses the defensin gene PDF1.2. Moreover, SA is required for the ssi1-conferred constitutive expression of PDF1.2 in addition to PR genes. Hence, the ssi1 mutant appears to target a step common to SA- and ethylene- or JA-regulated defense pathways. In the present study, we show that, in addition to SA, ethylene and JA signaling also are required for the ssi1-conferred constitutive expression of PDF1.2 and the NPR1-independent expression of PR-1. Furthermore, the ethylene-insensitive ein2 and JA-insensitive jar1 mutants enhance susceptibility of ssi1 plants to the necrotrophic fungus Botrytis cinerea. However, defects in either the ethylene- or JA-signaling pathways do not compromise ssi1-conferred resistance to the bacterial pathogen Pseudomonas syringae pv. maculicola and the oomycete pathogen Peronospora parasitica. Interestingly, ssi1 exhibits a marginal increase in the levels of ethylene and JA, suggesting that low endogenous levels of these phytohormones are sufficient to activate expression of defense genes. Taken together, our results indicate that although cross talk in ssi1 renders expression of ethylene- or JA-responsive defense genes sensitive to SA and vice versa, it does not affect downstream signaling leading to resistance.

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