Temperature-Inducible Transgenic EDS1 and PAD4 in Arabidopsis Confer an Enhanced Disease Resistance at Elevated Temperature

Temperature is one of the most important environmental factors greatly affecting plant disease development. High temperature favors outbreaks of many plant diseases, which threaten food security and turn to be a big issue along with climate change and global warming. Here, we found that concurrent constitutive expression of the key immune regulators EDS1 and PAD4 in Arabidopsis significantly enhanced resistance to virulent bacterial pathogen Pseudomonas syringae pv. tomato at elevated temperature; however, autoimmunity-related growth retardation was also observed on these plants at a normal temperature. To balance this growth-defense trade-off, we generated transgenic plants dual expressing EDS1 and PAD4 genes under the control of a thermo-sensitive promoter from the HSP70 gene, whose expression is highly induced at an elevated temperature. Unlike constitutive overexpression lines, the proHSP70-EP transgenic lines exhibited enhanced resistance to bacterial pathogens at an elevated temperature without growth defects at normal condition. Thus, this study provides a potential strategy for genetic manipulation of plants to deal with the simultaneous abiotic and biotic stresses.

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Cysteine protease RD21A regulated by E3 ligase SINAT4 is required for drought-induced resistance to Pseudomonas syringae in Arabidopsis

Journal of Experimental Botany ◽

10.1093/jxb/eraa255 ◽

2020 ◽

Vol 71 (18) ◽

pp. 5562-5576

Author(s):

Yi Liu ◽

Kunru Wang ◽

Qiang Cheng ◽

Danyu Kong ◽

Xunzhong Zhang ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Cysteine Protease ◽

Plant Immunity ◽

Stomatal Closure ◽

Bacterial Pathogen ◽

E3 Ligase ◽

Biotic Stresses ◽

Ubiquitin E3 Ligase ◽

Induced Immunity

Abstract Plants can be simultaneously exposed to multiple stresses. The interplay of abiotic and biotic stresses may result in synergistic or antagonistic effects on plant development and health. Temporary drought stress can stimulate plant immunity; however, the molecular mechanism of drought-induced immunity is largely unknown. In this study, we demonstrate that cysteine protease RD21A is required for drought-induced immunity. Temporarily drought-treated wild-type Arabidopsis plants became more sensitive to the bacterial pathogen-associated molecular pattern flg22, triggering stomatal closure, which resulted in increased resistance to Pseudomonas syringae pv. tomato DC3000 (Pst-DC3000). Knocking out rd21a inhibited flg22-triggered stomatal closure and compromised the drought-induced immunity. Ubiquitin E3 ligase SINAT4 interacted with RD21A and promoted its degradation in vivo. The overexpression of SINAT4 also consistently compromised the drought-induced immunity to Pst-DC3000. A bacterial type III effector, AvrRxo1, interacted with both SINAT4 and RD21A, enhancing SINAT4 activity and promoting the degradation of RD21A in vivo. Therefore, RD21A could be a positive regulator of drought-induced immunity, which could be targeted by pathogen virulence effectors during pathogenesis.

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Characterization of a Novel, Defense-Related Arabidopsis Mutant, cir1, Isolated By Luciferase Imaging

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2002.15.6.557 ◽

2002 ◽

Vol 15 (6) ◽

pp. 557-566 ◽

Cited By ~ 32

Author(s):

Shane L. Murray ◽

Catherine Thomson ◽

Andrea Chini ◽

Nick D. Read ◽

Gary J. Loake

Keyword(s):

Signaling Pathways ◽

Pseudomonas Syringae ◽

Constitutive Expression ◽

Bacterial Pathogen ◽

Negative Regulator ◽

Reactive Oxygen Intermediate ◽

Peronospora Parasitica ◽

Tomato Dc3000 ◽

Pathogen Invasion ◽

Arabidopsis Mutant

In order to identify components of the defense signaling network engaged following attempted pathogen invasion, we generated a novel PR-1∷luciferase (LUC) transgenic line that was deployed in an imaging-based screen to uncover defense-related mutants. The recessive mutant designated cir1 exhibited constitutive expression of salicylic acid (SA), jasmonic acid (JA)/ethylene, and reactive oxygen intermediate-dependent genes. Moreover, this mutation conferred resistance against the bacterial pathogen Pseudomonas syringae pv. tomato DC3000 and a virulent oomycete pathogen Peronospora parasitica Noco2. Epistasis analyses were undertaken between cir1 and mutants that disrupt the SA (npr1, nahG), JA (jar1), and ethylene (ET) (ein2) signaling pathways. While resistance against both P. syringae pv. tomato DC3000 and Peronospora parasitica Noco2 was partially reduced by npr1, resistance against both of these pathogens was lost in an nahG genetic background. Hence, cir1-mediated resistance is established via NPR1-dependent and -independent signaling pathways and SA accumulation is essential for the function of both pathways. While jar1 and ein2 reduced resistance against P. syringae pv. tomato DC3000, these mutations appeared not to impact cir1-mediated resistance against Peronospora parasitica Noco2. Thus, JA and ET sensitivity are required for cir1-mediated resistance against P. syringae pv. tomato DC3000 but not Peronospora parasitica Noco2. Therefore, the cir1 mutation may define a negative regulator of disease resistance that operates upstream of SA, JA, and ET accumulation.

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The Cuticle Mutant eca2 Modifies Plant Defense Responses to Biotrophic and Necrotrophic Pathogens and Herbivory Insects

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi-07-17-0181-r ◽

2018 ◽

Vol 31 (3) ◽

pp. 344-355 ◽

Cited By ~ 7

Author(s):

Catherine Blanc ◽

Fania Coluccia ◽

Floriane L’Haridon ◽

Martha Torres ◽

Marlene Ortiz-Berrocal ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Defense Mechanism ◽

Induced Defense ◽

Constitutive Expression ◽

Bacterial Pathogen ◽

Transcriptional Response ◽

Chemical Characterization ◽

Biotic Interactions ◽

Defense Responses ◽

Herbivorous Insect

We isolated previously several Arabidopsis thaliana mutants with constitutive expression of the early microbe-associated molecular pattern–induced gene ATL2, named eca (expresión constitutiva de ATL2). Here, we further explored the interaction of eca mutants with pest and pathogens. Of all eca mutants, eca2 was more resistant to a fungal pathogen (Botrytis cinerea) and a bacterial pathogen (Pseudomonas syringae) as well as to a generalist herbivorous insect (Spodoptera littoralis). Permeability of the cuticle is increased in eca2; chemical characterization shows that eca2 has a significant reduction of both cuticular wax and cutin. Additionally, we determined that eca2 did not display a similar compensatory transcriptional response, compared with a previously characterized cuticular mutant, and that resistance to B. cinerea is mediated by the priming of the early and late induced defense responses, including salicylic acid– and jasmonic acid–induced genes. These results suggest that ECA2-dependent responses are involved in the nonhost defense mechanism against biotrophic and necrotrophic pathogens and against a generalist insect by modulation and priming of innate immunity and late defense responses. Making eca2 an interesting model to characterize the molecular basis for plant defenses against different biotic interactions and to study the initial events that take place in the cuticle surface of the aerial organs.

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Constitutive Activation of Jasmonate Signaling in an Arabidopsis Mutant Correlates with Enhanced Resistance to Erysiphe cichoracearum, Pseudomonas syringae, and Myzus persicae

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2002.15.10.1025 ◽

2002 ◽

Vol 15 (10) ◽

pp. 1025-1030 ◽

Cited By ~ 191

Author(s):

Christine Ellis ◽

Ioannis Karafyllidis ◽

John G. Turner

Keyword(s):

Pseudomonas Syringae ◽

Myzus Persicae ◽

Green Peach Aphid ◽

Bacterial Pathogen ◽

Wild Type ◽

Defense Genes ◽

Erysiphe Cichoracearum ◽

Enhanced Resistance ◽

Arabidopsis Mutant ◽

Ja Signaling

In Arabidopsis spp., the jasmonate (JA) response pathway generally is required for defenses against necrotrophic pathogens and chewing insects, while the salicylic acid (SA) response pathway is generally required for specific, resistance (R) gene-mediated defenses against both biotrophic and necrotrophic pathogens. For example, SA-dependent defenses are required for resistance to the biotrophic fungal pathogen Erysiphe cichoracearum UCSC1 and the bacterial pathogen Pseudomonas syringae pv. maculicola, and also are expressed during response to the green peach aphid Myzus persicae. However, recent evidence indicates that the expression of JA-dependent defenses also may confer resistance to E. cichoracearum. To confirm and to extend this observation, we have compared the disease and pest resistance of wild-type Arabidopsis plants with that of the mutants coi1, which is insensitive to JA, and cev1, which has constitutive JA signaling. Measurements of the colonization of these plants by E. cichoracearum, P. syringae pv. maculicola, and M. persicae indicated that activation of the JA signal pathway enhanced resistance, and was associated with the activation of JA-dependent defense genes and the suppression of SA-dependent defense genes. We conclude that JA and SA induce alternative defense pathways that can confer resistance to the same pathogens and pests.

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Pathogens and Elicitors Induce Local and Systemic Changes in Triacylglycerol Metabolism in Roots and in Leaves of Arabidopsis thaliana

Biology ◽

10.3390/biology10090920 ◽

2021 ◽

Vol 10 (9) ◽

pp. 920

Author(s):

Sebastian Schieferle ◽

Beeke Tappe ◽

Pamela Korte ◽

Martin J. Mueller ◽

Susanne Berger

Keyword(s):

Arabidopsis Thaliana ◽

Abiotic Stress ◽

Lipid Metabolism ◽

Pseudomonas Syringae ◽

Bacterial Pathogen ◽

Biotic Stresses ◽

Triacylglycerol Metabolism ◽

Triacylglycerol Accumulation ◽

Insight Into ◽

Tof Ms

Interaction of plants with the environment affects lipid metabolism. Changes in the pattern of phospholipids have been reported in response to abiotic stress, particularly accumulation of triacylglycerols, but less is known about the alteration of lipid metabolism in response to biotic stress and leaves have been more intensively studied than roots. This work investigates the levels of lipids in roots as well as leaves of Arabidopsis thaliana in response to pathogens and elicitor molecules by UPLC-TOF-MS. Triacylglycerol levels increased in roots and systemically in leaves upon treatment of roots with the fungus Verticillium longisporum. Upon spray infection of leaves with the bacterial pathogen Pseudomonas syringae, triacylglycerols accumulated locally in leaves but not in roots. Treatment of roots with a bacterial lipopolysaccharide elicitor induced a strong triacylglycerol accumulation in roots and leaves. Induction of the expression of the bacterial effector AVRRPM1 resulted in a dramatic increase of triacylglycerol levels in leaves, indicating that elicitor molecules are sufficient to induce accumulation of triacylglycerols. These results give insight into local and systemic changes to lipid metabolism in roots and leaves in response to biotic stresses.

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Isolation and Characterization of Broad-Spectrum Disease-Resistant Arabidopsis Mutants

Genetics ◽

10.1093/genetics/160.4.1661 ◽

2002 ◽

Vol 160 (4) ◽

pp. 1661-1671

Author(s):

Klaus Maleck ◽

Urs Neuenschwander ◽

Rebecca M Cade ◽

Robert A Dietrich ◽

Jeffery L Dangl ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Systemic Acquired Resistance ◽

Acquired Resistance ◽

Constitutive Expression ◽

Firefly Luciferase ◽

Marker Genes ◽

Arabidopsis Mutants ◽

Isolation And Characterization ◽

Firefly Luciferase Gene

Abstract To identify Arabidopsis mutants that constitutively express systemic acquired resistance (SAR), we constructed reporter lines expressing the firefly luciferase gene under the control of the SAR-inducible PR-1 promoter (PR-1/luc). After EMS mutagenesis of a well-characterized transgenic line, we screened 250,000 M2 plants for constitutive expression of the reporter gene in vivo. From a mutant collection containing several hundred putative mutants, we concentrated on 16 mutants lacking spontaneous hypersensitive response (HR) cell death. We mapped 4 of these constitutive immunity (cim) mutants to chromosome arms. Constitutive expression of disease resistance was established by analyzing responses to virulent Peronospora parasitica and Pseudomonas syringae strains, by RNA blot analysis for endogenous marker genes, and by determination of salicylic acid levels in the mutants. The variety of the cim phenotypes allowed us to define distinct steps in both the canonical SAR signaling pathway and a separate pathway for resistance to Erysiphe cichoracearum, active in only a subset of the mutants.

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Transcriptomic and genetic approaches reveal an essential role of the NAC transcription factor SlNAP1 in the growth and defense response of tomato

Horticulture Research ◽

10.1038/s41438-020-00442-6 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Jiao Wang ◽

Chenfei Zheng ◽

Xiangqi Shao ◽

Zhangjian Hu ◽

Jianxin Li ◽

...

Keyword(s):

Pseudomonas Syringae ◽

Defense Response ◽

Global Climate ◽

Plant Responses ◽

Multiple Stresses ◽

Bacterial Diseases ◽

Bacterial Wilt Disease ◽

Transgenic Lines ◽

Breeding Target

AbstractWith global climate change, plants are frequently being exposed to various stresses, such as pathogen attack, drought, and extreme temperatures. Transcription factors (TFs) play crucial roles in numerous plant biological processes; however, the functions of many tomato (Solanum lycopersicum L.) TFs that regulate plant responses to multiple stresses are largely unknown. Here, using an RNA-seq approach, we identified SlNAP1, a NAC TF-encoding gene, which was strongly induced by various stresses. By generating SlNAP1 transgenic lines and evaluating their responses to biotic and abiotic stresses in tomato, we found that SlNAP1-overexpressing plants showed significantly enhanced defense against two widespread bacterial diseases, leaf speck disease, caused by Pseudomonas syringae pv. tomato (Pst) DC3000, and root-borne bacterial wilt disease, caused by Ralstonia solanacearum. In addition, SlNAP1 overexpression dramatically improved drought tolerance in tomato. Although the SlNAP1-overexpressing plants were shorter than the wild-type plants during the early vegetative stage, eventually, their fruit yield increased by 10.7%. Analysis of different hormone contents revealed a reduced level of physiologically active gibberellins (GAs) and an increased level of salicylic acid (SA) and abscisic acid (ABA) in the SlNAP1-overexpressing plants. Moreover, EMSAs and ChIP-qPCR assays showed that SlNAP1 directly activated the transcription of multiple genes involved in GA deactivation and both SA and ABA biosynthesis. Our findings reveal that SlNAP1 is a positive regulator of the tomato defense response against multiple stresses and thus may be a potential breeding target for improving crop yield and stress resistance.

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Systemic Acquired Resistance in Canola Is Linked with Pathogenesis-Related Gene Expression and Requires Salicylic Acid

Phytopathology ◽

10.1094/phyto-97-7-0794 ◽

2007 ◽

Vol 97 (7) ◽

pp. 794-802 ◽

Cited By ~ 29

Author(s):

Shobha D. Potlakayala ◽

Darwin W. Reed ◽

Patrick S. Covello ◽

Pierre R. Fobert

Keyword(s):

Salicylic Acid ◽

Pseudomonas Syringae ◽

Systemic Acquired Resistance ◽

Induced Defense ◽

Acquired Resistance ◽

Microbial Pathogens ◽

Broad Host Range ◽

Avirulent Strain ◽

Enhanced Resistance ◽

Pathogenesis Related

Systemic acquired resistance (SAR) is an induced defense response that confers long-lasting protection against a broad range of microbial pathogens. Here we show that treatment of Brassica napus plants with the SAR-inducing chemical benzo-(1,2,3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) significantly enhanced resistance against virulent strains of the bacterial pathogen Pseudomonas syringae pv. maculicola and the fungal pathogen Leptosphaeria maculans. Localized preinoculation of plants with an avirulent strain of P. syringae pv. maculicola also enhanced resistance to these pathogens but was not as effective as BTH treatment. Single applications of either SAR-inducing pretreatment were effective against P. syringae pv. maculicola, even when given more than 3 weeks prior to the secondary challenge. The pretreatments also led to the accumulation of pathogenesis-related (PR) genes, including BnPR-1 and BnPR-2, with higher levels of transcripts observed in the BTH-treatment material. B. napus plants expressing a bacterial salicylate hydroxylase transgene (NahG) that metabolizes salicylic acid to catechol were substantially compromised in SAR and accumulated reduced levels of PR gene transcripts when compared with untransformed controls. Thus, SAR in B. napus displays many of the hallmarks of classical SAR including long lasting and broad host range resistance, association with PR gene activation, and a requirement for salicylic acid.

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Overexpression of antizyme in the hearts of transgenic mice prevents the isoprenaline-induced increase in cardiac ornithine decarboxylase activity and polyamines, but does not prevent cardiac hypertrophy

Biochemical Journal ◽

10.1042/bj3500645 ◽

2000 ◽

Vol 350 (3) ◽

pp. 645-653 ◽

Cited By ~ 11

Author(s):

Caroline A. MACKINTOSH ◽

David J. FEITH ◽

Lisa M. SHANTZ ◽

Anthony E. PEGG

Keyword(s):

Transgenic Mice ◽

Ornithine Decarboxylase ◽

Prolonged Exposure ◽

Constitutive Expression ◽

Decarboxylase Activity ◽

Cardiac Growth ◽

Polyamine Content ◽

Transgenic Lines ◽

Response To Stress ◽

Polyamine Uptake

Two lines of transgenic mice were produced with constitutive expression of antizyme-1 in the heart, driven from the cardiac α-myosin heavy chain promoter. The use of engineered antizyme cDNA in which nucleotide 205 had been deleted eliminated the need for polyamine-mediated frameshifting, normally necessary for translation of antizyme mRNA, and thus ensured the constitutive expression of antizyme. Antizyme-1 is thought to be a major factor in regulating cellular polyamine content, acting both to inhibit ornithine decarboxylase (ODC) activity and to target it for degradation, as well as preventing polyamine uptake. The two transgenic lines had substantial, but different, levels of antizyme in the heart, as detected by Western blotting and by the ability of heart extracts to inhibit exogenous purified ODC. Despite the high levels of antizyme, endogenous ODC activity was not completely abolished, with 10– 39% remaining, depending on the transgenic line. Additionally, a relatively small decrease (30–32%) in cardiac spermidine content was observed, with levels of putrescine and spermine unaffected. Interestingly, although the two lines of transgenic mice had different antizyme expression levels, they had almost identical cardiac polyamine content. When treated with a single acute dose of isoprenaline (isoproterenol), cardiac ODC activity and putrescine content were substantially increased (by 14-fold and 4.7-fold respectively) in non-transgenic littermate mice, but these increases were completely prevented in the transgenic mice from both founder lines. Prolonged exposure to isoprenaline also caused increases in cardiac ODC activity and polyamine content, as well as an increase in cardiac growth, in non-transgenic mice. Although the increases in cardiac ODC activity and polyamine content were prevented in the transgenic mice from both founder lines, the increase in cardiac growth was unaffected. These transgenic mice thus provide a valuable model system in which to study the importance of polyamine levels in cardiac growth and electrophysiology in response to stress.

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In planta bacterial multi-omics analysis illuminates regulatory principles underlying plant-pathogen interactions

10.1101/822932 ◽

2019 ◽

Cited By ~ 1

Author(s):

Tatsuya Nobori ◽

Yiming Wang ◽

Jingni Wu ◽

Sara Christina Stolze ◽

Yayoi Tsuda ◽

...

Keyword(s):

Gene Regulation ◽

Pseudomonas Syringae ◽

Protein Level ◽

Plant Pathogens ◽

Plant Immunity ◽

Bacterial Pathogen ◽

Bacterial Virulence ◽

In Planta ◽

Bacterial Gene ◽

Global Food Security

AbstractUnderstanding how gene expression is regulated in plant pathogens is crucial for pest control and thus global food security. An integrated understanding of bacterial gene regulation in the host is dependent on multi-omic datasets, but these are largely lacking. Here, we simultaneously characterized the transcriptome and proteome of a foliar bacterial pathogen, Pseudomonas syringae, in Arabidopsis thaliana and identified a number of bacterial processes influenced by plant immunity at the mRNA and the protein level. We found instances of both concordant and discordant regulation of bacterial mRNAs and proteins. Notably, the tip component of bacterial type III secretion system was selectively suppressed by the plant salicylic acid pathway at the protein level, suggesting protein-level targeting of the bacterial virulence system by plant immunity. Furthermore, gene co-expression analysis illuminated previously unknown gene regulatory modules underlying bacterial virulence and their regulatory hierarchy. Collectively, the integrated in planta bacterial omics approach provides molecular insights into multiple layers of bacterial gene regulation that contribute to bacterial growth in planta and elucidate the role of plant immunity in controlling pathogens.

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